922 lines
39 KiB
Python
922 lines
39 KiB
Python
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from django.core.exceptions import FieldError
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from django.db import connections
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from django.db.backends.util import truncate_name
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from django.db.models.sql.constants import *
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from django.db.models.sql.datastructures import EmptyResultSet
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from django.db.models.sql.expressions import SQLEvaluator
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from django.db.models.sql.query import get_proxied_model, get_order_dir, \
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select_related_descend, Query
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class SQLCompiler(object):
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def __init__(self, query, connection, using):
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self.query = query
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self.connection = connection
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self.using = using
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self.quote_cache = {}
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# Check that the compiler will be able to execute the query
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for alias, aggregate in self.query.aggregate_select.items():
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self.connection.ops.check_aggregate_support(aggregate)
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def pre_sql_setup(self):
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"""
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Does any necessary class setup immediately prior to producing SQL. This
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is for things that can't necessarily be done in __init__ because we
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might not have all the pieces in place at that time.
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"""
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if not self.query.tables:
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self.query.join((None, self.query.model._meta.db_table, None, None))
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if (not self.query.select and self.query.default_cols and not
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self.query.included_inherited_models):
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self.query.setup_inherited_models()
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if self.query.select_related and not self.query.related_select_cols:
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self.fill_related_selections()
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def quote_name_unless_alias(self, name):
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"""
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A wrapper around connection.ops.quote_name that doesn't quote aliases
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for table names. This avoids problems with some SQL dialects that treat
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quoted strings specially (e.g. PostgreSQL).
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"""
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if name in self.quote_cache:
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return self.quote_cache[name]
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if ((name in self.query.alias_map and name not in self.query.table_map) or
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name in self.query.extra_select):
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self.quote_cache[name] = name
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return name
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r = self.connection.ops.quote_name(name)
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self.quote_cache[name] = r
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return r
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def as_sql(self, with_limits=True, with_col_aliases=False):
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"""
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Creates the SQL for this query. Returns the SQL string and list of
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parameters.
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If 'with_limits' is False, any limit/offset information is not included
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in the query.
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"""
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self.pre_sql_setup()
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out_cols = self.get_columns(with_col_aliases)
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ordering, ordering_group_by = self.get_ordering()
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# This must come after 'select' and 'ordering' -- see docstring of
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# get_from_clause() for details.
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from_, f_params = self.get_from_clause()
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qn = self.quote_name_unless_alias
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where, w_params = self.query.where.as_sql(qn=qn, connection=self.connection)
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having, h_params = self.query.having.as_sql(qn=qn, connection=self.connection)
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params = []
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for val in self.query.extra_select.itervalues():
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params.extend(val[1])
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result = ['SELECT']
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if self.query.distinct:
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result.append('DISTINCT')
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result.append(', '.join(out_cols + self.query.ordering_aliases))
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result.append('FROM')
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result.extend(from_)
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params.extend(f_params)
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if where:
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result.append('WHERE %s' % where)
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params.extend(w_params)
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if self.query.extra_where:
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if not where:
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result.append('WHERE')
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else:
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result.append('AND')
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result.append(' AND '.join(self.query.extra_where))
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grouping, gb_params = self.get_grouping()
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if grouping:
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if ordering:
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# If the backend can't group by PK (i.e., any database
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# other than MySQL), then any fields mentioned in the
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# ordering clause needs to be in the group by clause.
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if not self.connection.features.allows_group_by_pk:
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for col, col_params in ordering_group_by:
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if col not in grouping:
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grouping.append(str(col))
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gb_params.extend(col_params)
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else:
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ordering = self.connection.ops.force_no_ordering()
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result.append('GROUP BY %s' % ', '.join(grouping))
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params.extend(gb_params)
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if having:
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result.append('HAVING %s' % having)
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params.extend(h_params)
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if ordering:
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result.append('ORDER BY %s' % ', '.join(ordering))
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if with_limits:
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if self.query.high_mark is not None:
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result.append('LIMIT %d' % (self.query.high_mark - self.query.low_mark))
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if self.query.low_mark:
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if self.query.high_mark is None:
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val = self.connection.ops.no_limit_value()
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if val:
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result.append('LIMIT %d' % val)
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result.append('OFFSET %d' % self.query.low_mark)
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params.extend(self.query.extra_params)
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return ' '.join(result), tuple(params)
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def as_nested_sql(self):
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"""
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Perform the same functionality as the as_sql() method, returning an
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SQL string and parameters. However, the alias prefixes are bumped
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beforehand (in a copy -- the current query isn't changed) and any
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ordering is removed.
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Used when nesting this query inside another.
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"""
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obj = self.query.clone()
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obj.clear_ordering(True)
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obj.bump_prefix()
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return obj.get_compiler(connection=self.connection).as_sql()
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def get_columns(self, with_aliases=False):
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"""
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Returns the list of columns to use in the select statement. If no
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columns have been specified, returns all columns relating to fields in
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the model.
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If 'with_aliases' is true, any column names that are duplicated
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(without the table names) are given unique aliases. This is needed in
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some cases to avoid ambiguity with nested queries.
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"""
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qn = self.quote_name_unless_alias
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qn2 = self.connection.ops.quote_name
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result = ['(%s) AS %s' % (col[0], qn2(alias)) for alias, col in self.query.extra_select.iteritems()]
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aliases = set(self.query.extra_select.keys())
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if with_aliases:
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col_aliases = aliases.copy()
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else:
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col_aliases = set()
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if self.query.select:
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only_load = self.deferred_to_columns()
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for col in self.query.select:
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if isinstance(col, (list, tuple)):
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alias, column = col
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table = self.query.alias_map[alias][TABLE_NAME]
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if table in only_load and col not in only_load[table]:
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continue
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r = '%s.%s' % (qn(alias), qn(column))
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if with_aliases:
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if col[1] in col_aliases:
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c_alias = 'Col%d' % len(col_aliases)
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result.append('%s AS %s' % (r, c_alias))
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aliases.add(c_alias)
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col_aliases.add(c_alias)
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else:
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result.append('%s AS %s' % (r, qn2(col[1])))
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aliases.add(r)
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col_aliases.add(col[1])
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else:
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result.append(r)
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aliases.add(r)
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col_aliases.add(col[1])
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else:
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result.append(col.as_sql(qn, self.connection))
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if hasattr(col, 'alias'):
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aliases.add(col.alias)
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col_aliases.add(col.alias)
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elif self.query.default_cols:
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cols, new_aliases = self.get_default_columns(with_aliases,
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col_aliases)
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result.extend(cols)
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aliases.update(new_aliases)
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max_name_length = self.connection.ops.max_name_length()
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result.extend([
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'%s%s' % (
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aggregate.as_sql(qn, self.connection),
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alias is not None
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and ' AS %s' % qn(truncate_name(alias, max_name_length))
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or ''
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)
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for alias, aggregate in self.query.aggregate_select.items()
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])
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for table, col in self.query.related_select_cols:
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r = '%s.%s' % (qn(table), qn(col))
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if with_aliases and col in col_aliases:
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c_alias = 'Col%d' % len(col_aliases)
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result.append('%s AS %s' % (r, c_alias))
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aliases.add(c_alias)
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col_aliases.add(c_alias)
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else:
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result.append(r)
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aliases.add(r)
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col_aliases.add(col)
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self._select_aliases = aliases
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return result
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def get_default_columns(self, with_aliases=False, col_aliases=None,
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start_alias=None, opts=None, as_pairs=False):
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"""
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Computes the default columns for selecting every field in the base
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model. Will sometimes be called to pull in related models (e.g. via
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select_related), in which case "opts" and "start_alias" will be given
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to provide a starting point for the traversal.
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Returns a list of strings, quoted appropriately for use in SQL
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directly, as well as a set of aliases used in the select statement (if
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'as_pairs' is True, returns a list of (alias, col_name) pairs instead
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of strings as the first component and None as the second component).
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"""
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result = []
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if opts is None:
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opts = self.query.model._meta
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qn = self.quote_name_unless_alias
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qn2 = self.connection.ops.quote_name
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aliases = set()
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only_load = self.deferred_to_columns()
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# Skip all proxy to the root proxied model
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proxied_model = get_proxied_model(opts)
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if start_alias:
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seen = {None: start_alias}
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for field, model in opts.get_fields_with_model():
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if start_alias:
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try:
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alias = seen[model]
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except KeyError:
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if model is proxied_model:
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alias = start_alias
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else:
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link_field = opts.get_ancestor_link(model)
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alias = self.query.join((start_alias, model._meta.db_table,
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link_field.column, model._meta.pk.column))
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seen[model] = alias
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else:
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# If we're starting from the base model of the queryset, the
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# aliases will have already been set up in pre_sql_setup(), so
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# we can save time here.
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alias = self.query.included_inherited_models[model]
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table = self.query.alias_map[alias][TABLE_NAME]
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if table in only_load and field.column not in only_load[table]:
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continue
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if as_pairs:
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result.append((alias, field.column))
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aliases.add(alias)
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continue
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if with_aliases and field.column in col_aliases:
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c_alias = 'Col%d' % len(col_aliases)
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result.append('%s.%s AS %s' % (qn(alias),
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qn2(field.column), c_alias))
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col_aliases.add(c_alias)
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aliases.add(c_alias)
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else:
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r = '%s.%s' % (qn(alias), qn2(field.column))
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result.append(r)
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aliases.add(r)
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if with_aliases:
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col_aliases.add(field.column)
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return result, aliases
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def get_ordering(self):
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"""
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Returns a tuple containing a list representing the SQL elements in the
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"order by" clause, and the list of SQL elements that need to be added
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to the GROUP BY clause as a result of the ordering.
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Also sets the ordering_aliases attribute on this instance to a list of
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extra aliases needed in the select.
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Determining the ordering SQL can change the tables we need to include,
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so this should be run *before* get_from_clause().
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"""
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if self.query.extra_order_by:
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ordering = self.query.extra_order_by
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elif not self.query.default_ordering:
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ordering = self.query.order_by
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else:
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ordering = self.query.order_by or self.query.model._meta.ordering
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qn = self.quote_name_unless_alias
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qn2 = self.connection.ops.quote_name
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distinct = self.query.distinct
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select_aliases = self._select_aliases
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result = []
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group_by = []
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ordering_aliases = []
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if self.query.standard_ordering:
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asc, desc = ORDER_DIR['ASC']
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else:
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asc, desc = ORDER_DIR['DESC']
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# It's possible, due to model inheritance, that normal usage might try
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# to include the same field more than once in the ordering. We track
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# the table/column pairs we use and discard any after the first use.
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processed_pairs = set()
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for field in ordering:
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if field == '?':
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result.append(self.connection.ops.random_function_sql())
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continue
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if isinstance(field, int):
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if field < 0:
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order = desc
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field = -field
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else:
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order = asc
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result.append('%s %s' % (field, order))
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group_by.append((field, []))
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continue
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col, order = get_order_dir(field, asc)
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if col in self.query.aggregate_select:
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result.append('%s %s' % (col, order))
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continue
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if '.' in field:
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# This came in through an extra(order_by=...) addition. Pass it
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# on verbatim.
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table, col = col.split('.', 1)
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if (table, col) not in processed_pairs:
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elt = '%s.%s' % (qn(table), col)
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processed_pairs.add((table, col))
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if not distinct or elt in select_aliases:
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result.append('%s %s' % (elt, order))
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group_by.append((elt, []))
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elif get_order_dir(field)[0] not in self.query.extra_select:
|
||
|
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# 'col' is of the form 'field' or 'field1__field2' or
|
||
|
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# '-field1__field2__field', etc.
|
||
|
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for table, col, order in self.find_ordering_name(field,
|
||
|
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self.query.model._meta, default_order=asc):
|
||
|
|
if (table, col) not in processed_pairs:
|
||
|
|
elt = '%s.%s' % (qn(table), qn2(col))
|
||
|
|
processed_pairs.add((table, col))
|
||
|
|
if distinct and elt not in select_aliases:
|
||
|
|
ordering_aliases.append(elt)
|
||
|
|
result.append('%s %s' % (elt, order))
|
||
|
|
group_by.append((elt, []))
|
||
|
|
else:
|
||
|
|
elt = qn2(col)
|
||
|
|
if distinct and col not in select_aliases:
|
||
|
|
ordering_aliases.append(elt)
|
||
|
|
result.append('%s %s' % (elt, order))
|
||
|
|
group_by.append(self.query.extra_select[col])
|
||
|
|
self.query.ordering_aliases = ordering_aliases
|
||
|
|
return result, group_by
|
||
|
|
|
||
|
|
def find_ordering_name(self, name, opts, alias=None, default_order='ASC',
|
||
|
|
already_seen=None):
|
||
|
|
"""
|
||
|
|
Returns the table alias (the name might be ambiguous, the alias will
|
||
|
|
not be) and column name for ordering by the given 'name' parameter.
|
||
|
|
The 'name' is of the form 'field1__field2__...__fieldN'.
|
||
|
|
"""
|
||
|
|
name, order = get_order_dir(name, default_order)
|
||
|
|
pieces = name.split(LOOKUP_SEP)
|
||
|
|
if not alias:
|
||
|
|
alias = self.query.get_initial_alias()
|
||
|
|
field, target, opts, joins, last, extra = self.query.setup_joins(pieces,
|
||
|
|
opts, alias, False)
|
||
|
|
alias = joins[-1]
|
||
|
|
col = target.column
|
||
|
|
if not field.rel:
|
||
|
|
# To avoid inadvertent trimming of a necessary alias, use the
|
||
|
|
# refcount to show that we are referencing a non-relation field on
|
||
|
|
# the model.
|
||
|
|
self.query.ref_alias(alias)
|
||
|
|
|
||
|
|
# Must use left outer joins for nullable fields and their relations.
|
||
|
|
self.query.promote_alias_chain(joins,
|
||
|
|
self.query.alias_map[joins[0]][JOIN_TYPE] == self.query.LOUTER)
|
||
|
|
|
||
|
|
# If we get to this point and the field is a relation to another model,
|
||
|
|
# append the default ordering for that model.
|
||
|
|
if field.rel and len(joins) > 1 and opts.ordering:
|
||
|
|
# Firstly, avoid infinite loops.
|
||
|
|
if not already_seen:
|
||
|
|
already_seen = set()
|
||
|
|
join_tuple = tuple([self.query.alias_map[j][TABLE_NAME] for j in joins])
|
||
|
|
if join_tuple in already_seen:
|
||
|
|
raise FieldError('Infinite loop caused by ordering.')
|
||
|
|
already_seen.add(join_tuple)
|
||
|
|
|
||
|
|
results = []
|
||
|
|
for item in opts.ordering:
|
||
|
|
results.extend(self.find_ordering_name(item, opts, alias,
|
||
|
|
order, already_seen))
|
||
|
|
return results
|
||
|
|
|
||
|
|
if alias:
|
||
|
|
# We have to do the same "final join" optimisation as in
|
||
|
|
# add_filter, since the final column might not otherwise be part of
|
||
|
|
# the select set (so we can't order on it).
|
||
|
|
while 1:
|
||
|
|
join = self.query.alias_map[alias]
|
||
|
|
if col != join[RHS_JOIN_COL]:
|
||
|
|
break
|
||
|
|
self.query.unref_alias(alias)
|
||
|
|
alias = join[LHS_ALIAS]
|
||
|
|
col = join[LHS_JOIN_COL]
|
||
|
|
return [(alias, col, order)]
|
||
|
|
|
||
|
|
def get_from_clause(self):
|
||
|
|
"""
|
||
|
|
Returns a list of strings that are joined together to go after the
|
||
|
|
"FROM" part of the query, as well as a list any extra parameters that
|
||
|
|
need to be included. Sub-classes, can override this to create a
|
||
|
|
from-clause via a "select".
|
||
|
|
|
||
|
|
This should only be called after any SQL construction methods that
|
||
|
|
might change the tables we need. This means the select columns and
|
||
|
|
ordering must be done first.
|
||
|
|
"""
|
||
|
|
result = []
|
||
|
|
qn = self.quote_name_unless_alias
|
||
|
|
qn2 = self.connection.ops.quote_name
|
||
|
|
first = True
|
||
|
|
for alias in self.query.tables:
|
||
|
|
if not self.query.alias_refcount[alias]:
|
||
|
|
continue
|
||
|
|
try:
|
||
|
|
name, alias, join_type, lhs, lhs_col, col, nullable = self.query.alias_map[alias]
|
||
|
|
except KeyError:
|
||
|
|
# Extra tables can end up in self.tables, but not in the
|
||
|
|
# alias_map if they aren't in a join. That's OK. We skip them.
|
||
|
|
continue
|
||
|
|
alias_str = (alias != name and ' %s' % alias or '')
|
||
|
|
if join_type and not first:
|
||
|
|
result.append('%s %s%s ON (%s.%s = %s.%s)'
|
||
|
|
% (join_type, qn(name), alias_str, qn(lhs),
|
||
|
|
qn2(lhs_col), qn(alias), qn2(col)))
|
||
|
|
else:
|
||
|
|
connector = not first and ', ' or ''
|
||
|
|
result.append('%s%s%s' % (connector, qn(name), alias_str))
|
||
|
|
first = False
|
||
|
|
for t in self.query.extra_tables:
|
||
|
|
alias, unused = self.query.table_alias(t)
|
||
|
|
# Only add the alias if it's not already present (the table_alias()
|
||
|
|
# calls increments the refcount, so an alias refcount of one means
|
||
|
|
# this is the only reference.
|
||
|
|
if alias not in self.query.alias_map or self.query.alias_refcount[alias] == 1:
|
||
|
|
connector = not first and ', ' or ''
|
||
|
|
result.append('%s%s' % (connector, qn(alias)))
|
||
|
|
first = False
|
||
|
|
return result, []
|
||
|
|
|
||
|
|
def get_grouping(self):
|
||
|
|
"""
|
||
|
|
Returns a tuple representing the SQL elements in the "group by" clause.
|
||
|
|
"""
|
||
|
|
qn = self.quote_name_unless_alias
|
||
|
|
result, params = [], []
|
||
|
|
if self.query.group_by is not None:
|
||
|
|
if len(self.query.model._meta.fields) == len(self.query.select) and \
|
||
|
|
self.connection.features.allows_group_by_pk:
|
||
|
|
self.query.group_by = [(self.query.model._meta.db_table, self.query.model._meta.pk.column)]
|
||
|
|
|
||
|
|
group_by = self.query.group_by or []
|
||
|
|
|
||
|
|
extra_selects = []
|
||
|
|
for extra_select, extra_params in self.query.extra_select.itervalues():
|
||
|
|
extra_selects.append(extra_select)
|
||
|
|
params.extend(extra_params)
|
||
|
|
for col in group_by + self.query.related_select_cols + extra_selects:
|
||
|
|
if isinstance(col, (list, tuple)):
|
||
|
|
result.append('%s.%s' % (qn(col[0]), qn(col[1])))
|
||
|
|
elif hasattr(col, 'as_sql'):
|
||
|
|
result.append(col.as_sql(qn))
|
||
|
|
else:
|
||
|
|
result.append(str(col))
|
||
|
|
return result, params
|
||
|
|
|
||
|
|
def fill_related_selections(self, opts=None, root_alias=None, cur_depth=1,
|
||
|
|
used=None, requested=None, restricted=None, nullable=None,
|
||
|
|
dupe_set=None, avoid_set=None):
|
||
|
|
"""
|
||
|
|
Fill in the information needed for a select_related query. The current
|
||
|
|
depth is measured as the number of connections away from the root model
|
||
|
|
(for example, cur_depth=1 means we are looking at models with direct
|
||
|
|
connections to the root model).
|
||
|
|
"""
|
||
|
|
if not restricted and self.query.max_depth and cur_depth > self.query.max_depth:
|
||
|
|
# We've recursed far enough; bail out.
|
||
|
|
return
|
||
|
|
|
||
|
|
if not opts:
|
||
|
|
opts = self.query.get_meta()
|
||
|
|
root_alias = self.query.get_initial_alias()
|
||
|
|
self.query.related_select_cols = []
|
||
|
|
self.query.related_select_fields = []
|
||
|
|
if not used:
|
||
|
|
used = set()
|
||
|
|
if dupe_set is None:
|
||
|
|
dupe_set = set()
|
||
|
|
if avoid_set is None:
|
||
|
|
avoid_set = set()
|
||
|
|
orig_dupe_set = dupe_set
|
||
|
|
|
||
|
|
# Setup for the case when only particular related fields should be
|
||
|
|
# included in the related selection.
|
||
|
|
if requested is None and restricted is not False:
|
||
|
|
if isinstance(self.query.select_related, dict):
|
||
|
|
requested = self.query.select_related
|
||
|
|
restricted = True
|
||
|
|
else:
|
||
|
|
restricted = False
|
||
|
|
|
||
|
|
for f, model in opts.get_fields_with_model():
|
||
|
|
if not select_related_descend(f, restricted, requested):
|
||
|
|
continue
|
||
|
|
# The "avoid" set is aliases we want to avoid just for this
|
||
|
|
# particular branch of the recursion. They aren't permanently
|
||
|
|
# forbidden from reuse in the related selection tables (which is
|
||
|
|
# what "used" specifies).
|
||
|
|
avoid = avoid_set.copy()
|
||
|
|
dupe_set = orig_dupe_set.copy()
|
||
|
|
table = f.rel.to._meta.db_table
|
||
|
|
if nullable or f.null:
|
||
|
|
promote = True
|
||
|
|
else:
|
||
|
|
promote = False
|
||
|
|
if model:
|
||
|
|
int_opts = opts
|
||
|
|
alias = root_alias
|
||
|
|
alias_chain = []
|
||
|
|
for int_model in opts.get_base_chain(model):
|
||
|
|
# Proxy model have elements in base chain
|
||
|
|
# with no parents, assign the new options
|
||
|
|
# object and skip to the next base in that
|
||
|
|
# case
|
||
|
|
if not int_opts.parents[int_model]:
|
||
|
|
int_opts = int_model._meta
|
||
|
|
continue
|
||
|
|
lhs_col = int_opts.parents[int_model].column
|
||
|
|
dedupe = lhs_col in opts.duplicate_targets
|
||
|
|
if dedupe:
|
||
|
|
avoid.update(self.query.dupe_avoidance.get(id(opts), lhs_col),
|
||
|
|
())
|
||
|
|
dupe_set.add((opts, lhs_col))
|
||
|
|
int_opts = int_model._meta
|
||
|
|
alias = self.query.join((alias, int_opts.db_table, lhs_col,
|
||
|
|
int_opts.pk.column), exclusions=used,
|
||
|
|
promote=promote)
|
||
|
|
alias_chain.append(alias)
|
||
|
|
for (dupe_opts, dupe_col) in dupe_set:
|
||
|
|
self.query.update_dupe_avoidance(dupe_opts, dupe_col, alias)
|
||
|
|
if self.query.alias_map[root_alias][JOIN_TYPE] == self.query.LOUTER:
|
||
|
|
self.query.promote_alias_chain(alias_chain, True)
|
||
|
|
else:
|
||
|
|
alias = root_alias
|
||
|
|
|
||
|
|
dedupe = f.column in opts.duplicate_targets
|
||
|
|
if dupe_set or dedupe:
|
||
|
|
avoid.update(self.query.dupe_avoidance.get((id(opts), f.column), ()))
|
||
|
|
if dedupe:
|
||
|
|
dupe_set.add((opts, f.column))
|
||
|
|
|
||
|
|
alias = self.query.join((alias, table, f.column,
|
||
|
|
f.rel.get_related_field().column),
|
||
|
|
exclusions=used.union(avoid), promote=promote)
|
||
|
|
used.add(alias)
|
||
|
|
columns, aliases = self.get_default_columns(start_alias=alias,
|
||
|
|
opts=f.rel.to._meta, as_pairs=True)
|
||
|
|
self.query.related_select_cols.extend(columns)
|
||
|
|
if self.query.alias_map[alias][JOIN_TYPE] == self.query.LOUTER:
|
||
|
|
self.query.promote_alias_chain(aliases, True)
|
||
|
|
self.query.related_select_fields.extend(f.rel.to._meta.fields)
|
||
|
|
if restricted:
|
||
|
|
next = requested.get(f.name, {})
|
||
|
|
else:
|
||
|
|
next = False
|
||
|
|
if f.null is not None:
|
||
|
|
new_nullable = f.null
|
||
|
|
else:
|
||
|
|
new_nullable = None
|
||
|
|
for dupe_opts, dupe_col in dupe_set:
|
||
|
|
self.query.update_dupe_avoidance(dupe_opts, dupe_col, alias)
|
||
|
|
self.fill_related_selections(f.rel.to._meta, alias, cur_depth + 1,
|
||
|
|
used, next, restricted, new_nullable, dupe_set, avoid)
|
||
|
|
|
||
|
|
def deferred_to_columns(self):
|
||
|
|
"""
|
||
|
|
Converts the self.deferred_loading data structure to mapping of table
|
||
|
|
names to sets of column names which are to be loaded. Returns the
|
||
|
|
dictionary.
|
||
|
|
"""
|
||
|
|
columns = {}
|
||
|
|
self.query.deferred_to_data(columns, self.query.deferred_to_columns_cb)
|
||
|
|
return columns
|
||
|
|
|
||
|
|
def results_iter(self):
|
||
|
|
"""
|
||
|
|
Returns an iterator over the results from executing this query.
|
||
|
|
"""
|
||
|
|
resolve_columns = hasattr(self, 'resolve_columns')
|
||
|
|
fields = None
|
||
|
|
for rows in self.execute_sql(MULTI):
|
||
|
|
for row in rows:
|
||
|
|
if resolve_columns:
|
||
|
|
if fields is None:
|
||
|
|
# We only set this up here because
|
||
|
|
# related_select_fields isn't populated until
|
||
|
|
# execute_sql() has been called.
|
||
|
|
if self.query.select_fields:
|
||
|
|
fields = self.query.select_fields + self.query.related_select_fields
|
||
|
|
else:
|
||
|
|
fields = self.query.model._meta.fields
|
||
|
|
# If the field was deferred, exclude it from being passed
|
||
|
|
# into `resolve_columns` because it wasn't selected.
|
||
|
|
only_load = self.deferred_to_columns()
|
||
|
|
if only_load:
|
||
|
|
db_table = self.query.model._meta.db_table
|
||
|
|
fields = [f for f in fields if db_table in only_load and
|
||
|
|
f.column in only_load[db_table]]
|
||
|
|
row = self.resolve_columns(row, fields)
|
||
|
|
|
||
|
|
if self.query.aggregate_select:
|
||
|
|
aggregate_start = len(self.query.extra_select.keys()) + len(self.query.select)
|
||
|
|
aggregate_end = aggregate_start + len(self.query.aggregate_select)
|
||
|
|
row = tuple(row[:aggregate_start]) + tuple([
|
||
|
|
self.query.resolve_aggregate(value, aggregate, self.connection)
|
||
|
|
for (alias, aggregate), value
|
||
|
|
in zip(self.query.aggregate_select.items(), row[aggregate_start:aggregate_end])
|
||
|
|
]) + tuple(row[aggregate_end:])
|
||
|
|
|
||
|
|
yield row
|
||
|
|
|
||
|
|
def execute_sql(self, result_type=MULTI):
|
||
|
|
"""
|
||
|
|
Run the query against the database and returns the result(s). The
|
||
|
|
return value is a single data item if result_type is SINGLE, or an
|
||
|
|
iterator over the results if the result_type is MULTI.
|
||
|
|
|
||
|
|
result_type is either MULTI (use fetchmany() to retrieve all rows),
|
||
|
|
SINGLE (only retrieve a single row), or None. In this last case, the
|
||
|
|
cursor is returned if any query is executed, since it's used by
|
||
|
|
subclasses such as InsertQuery). It's possible, however, that no query
|
||
|
|
is needed, as the filters describe an empty set. In that case, None is
|
||
|
|
returned, to avoid any unnecessary database interaction.
|
||
|
|
"""
|
||
|
|
try:
|
||
|
|
sql, params = self.as_sql()
|
||
|
|
if not sql:
|
||
|
|
raise EmptyResultSet
|
||
|
|
except EmptyResultSet:
|
||
|
|
if result_type == MULTI:
|
||
|
|
return empty_iter()
|
||
|
|
else:
|
||
|
|
return
|
||
|
|
|
||
|
|
cursor = self.connection.cursor()
|
||
|
|
cursor.execute(sql, params)
|
||
|
|
|
||
|
|
if not result_type:
|
||
|
|
return cursor
|
||
|
|
if result_type == SINGLE:
|
||
|
|
if self.query.ordering_aliases:
|
||
|
|
return cursor.fetchone()[:-len(self.query.ordering_aliases)]
|
||
|
|
return cursor.fetchone()
|
||
|
|
|
||
|
|
# The MULTI case.
|
||
|
|
if self.query.ordering_aliases:
|
||
|
|
result = order_modified_iter(cursor, len(self.query.ordering_aliases),
|
||
|
|
self.connection.features.empty_fetchmany_value)
|
||
|
|
else:
|
||
|
|
result = iter((lambda: cursor.fetchmany(GET_ITERATOR_CHUNK_SIZE)),
|
||
|
|
self.connection.features.empty_fetchmany_value)
|
||
|
|
if not self.connection.features.can_use_chunked_reads:
|
||
|
|
# If we are using non-chunked reads, we return the same data
|
||
|
|
# structure as normally, but ensure it is all read into memory
|
||
|
|
# before going any further.
|
||
|
|
return list(result)
|
||
|
|
return result
|
||
|
|
|
||
|
|
|
||
|
|
class SQLInsertCompiler(SQLCompiler):
|
||
|
|
def placeholder(self, field, val):
|
||
|
|
if field is None:
|
||
|
|
# A field value of None means the value is raw.
|
||
|
|
return val
|
||
|
|
elif hasattr(field, 'get_placeholder'):
|
||
|
|
# Some fields (e.g. geo fields) need special munging before
|
||
|
|
# they can be inserted.
|
||
|
|
return field.get_placeholder(val, self.connection)
|
||
|
|
else:
|
||
|
|
# Return the common case for the placeholder
|
||
|
|
return '%s'
|
||
|
|
|
||
|
|
def as_sql(self):
|
||
|
|
# We don't need quote_name_unless_alias() here, since these are all
|
||
|
|
# going to be column names (so we can avoid the extra overhead).
|
||
|
|
qn = self.connection.ops.quote_name
|
||
|
|
opts = self.query.model._meta
|
||
|
|
result = ['INSERT INTO %s' % qn(opts.db_table)]
|
||
|
|
result.append('(%s)' % ', '.join([qn(c) for c in self.query.columns]))
|
||
|
|
values = [self.placeholder(*v) for v in self.query.values]
|
||
|
|
result.append('VALUES (%s)' % ', '.join(values))
|
||
|
|
params = self.query.params
|
||
|
|
if self.return_id and self.connection.features.can_return_id_from_insert:
|
||
|
|
col = "%s.%s" % (qn(opts.db_table), qn(opts.pk.column))
|
||
|
|
r_fmt, r_params = self.connection.ops.return_insert_id()
|
||
|
|
result.append(r_fmt % col)
|
||
|
|
params = params + r_params
|
||
|
|
return ' '.join(result), params
|
||
|
|
|
||
|
|
def execute_sql(self, return_id=False):
|
||
|
|
self.return_id = return_id
|
||
|
|
cursor = super(SQLInsertCompiler, self).execute_sql(None)
|
||
|
|
if not (return_id and cursor):
|
||
|
|
return
|
||
|
|
if self.connection.features.can_return_id_from_insert:
|
||
|
|
return self.connection.ops.fetch_returned_insert_id(cursor)
|
||
|
|
return self.connection.ops.last_insert_id(cursor,
|
||
|
|
self.query.model._meta.db_table, self.query.model._meta.pk.column)
|
||
|
|
|
||
|
|
|
||
|
|
class SQLDeleteCompiler(SQLCompiler):
|
||
|
|
def as_sql(self):
|
||
|
|
"""
|
||
|
|
Creates the SQL for this query. Returns the SQL string and list of
|
||
|
|
parameters.
|
||
|
|
"""
|
||
|
|
assert len(self.query.tables) == 1, \
|
||
|
|
"Can only delete from one table at a time."
|
||
|
|
qn = self.quote_name_unless_alias
|
||
|
|
result = ['DELETE FROM %s' % qn(self.query.tables[0])]
|
||
|
|
where, params = self.query.where.as_sql(qn=qn, connection=self.connection)
|
||
|
|
result.append('WHERE %s' % where)
|
||
|
|
return ' '.join(result), tuple(params)
|
||
|
|
|
||
|
|
class SQLUpdateCompiler(SQLCompiler):
|
||
|
|
def as_sql(self):
|
||
|
|
"""
|
||
|
|
Creates the SQL for this query. Returns the SQL string and list of
|
||
|
|
parameters.
|
||
|
|
"""
|
||
|
|
from django.db.models.base import Model
|
||
|
|
|
||
|
|
self.pre_sql_setup()
|
||
|
|
if not self.query.values:
|
||
|
|
return '', ()
|
||
|
|
table = self.query.tables[0]
|
||
|
|
qn = self.quote_name_unless_alias
|
||
|
|
result = ['UPDATE %s' % qn(table)]
|
||
|
|
result.append('SET')
|
||
|
|
values, update_params = [], []
|
||
|
|
for field, model, val in self.query.values:
|
||
|
|
if hasattr(val, 'prepare_database_save'):
|
||
|
|
val = val.prepare_database_save(field)
|
||
|
|
else:
|
||
|
|
val = field.get_db_prep_save(val, connection=self.connection)
|
||
|
|
|
||
|
|
# Getting the placeholder for the field.
|
||
|
|
if hasattr(field, 'get_placeholder'):
|
||
|
|
placeholder = field.get_placeholder(val, self.connection)
|
||
|
|
else:
|
||
|
|
placeholder = '%s'
|
||
|
|
|
||
|
|
if hasattr(val, 'evaluate'):
|
||
|
|
val = SQLEvaluator(val, self.query, allow_joins=False)
|
||
|
|
name = field.column
|
||
|
|
if hasattr(val, 'as_sql'):
|
||
|
|
sql, params = val.as_sql(qn, self.connection)
|
||
|
|
values.append('%s = %s' % (qn(name), sql))
|
||
|
|
update_params.extend(params)
|
||
|
|
elif val is not None:
|
||
|
|
values.append('%s = %s' % (qn(name), placeholder))
|
||
|
|
update_params.append(val)
|
||
|
|
else:
|
||
|
|
values.append('%s = NULL' % qn(name))
|
||
|
|
if not values:
|
||
|
|
return '', ()
|
||
|
|
result.append(', '.join(values))
|
||
|
|
where, params = self.query.where.as_sql(qn=qn, connection=self.connection)
|
||
|
|
if where:
|
||
|
|
result.append('WHERE %s' % where)
|
||
|
|
return ' '.join(result), tuple(update_params + params)
|
||
|
|
|
||
|
|
def execute_sql(self, result_type):
|
||
|
|
"""
|
||
|
|
Execute the specified update. Returns the number of rows affected by
|
||
|
|
the primary update query. The "primary update query" is the first
|
||
|
|
non-empty query that is executed. Row counts for any subsequent,
|
||
|
|
related queries are not available.
|
||
|
|
"""
|
||
|
|
cursor = super(SQLUpdateCompiler, self).execute_sql(result_type)
|
||
|
|
rows = cursor and cursor.rowcount or 0
|
||
|
|
is_empty = cursor is None
|
||
|
|
del cursor
|
||
|
|
for query in self.query.get_related_updates():
|
||
|
|
aux_rows = query.get_compiler(self.using).execute_sql(result_type)
|
||
|
|
if is_empty:
|
||
|
|
rows = aux_rows
|
||
|
|
is_empty = False
|
||
|
|
return rows
|
||
|
|
|
||
|
|
def pre_sql_setup(self):
|
||
|
|
"""
|
||
|
|
If the update depends on results from other tables, we need to do some
|
||
|
|
munging of the "where" conditions to match the format required for
|
||
|
|
(portable) SQL updates. That is done here.
|
||
|
|
|
||
|
|
Further, if we are going to be running multiple updates, we pull out
|
||
|
|
the id values to update at this point so that they don't change as a
|
||
|
|
result of the progressive updates.
|
||
|
|
"""
|
||
|
|
self.query.select_related = False
|
||
|
|
self.query.clear_ordering(True)
|
||
|
|
super(SQLUpdateCompiler, self).pre_sql_setup()
|
||
|
|
count = self.query.count_active_tables()
|
||
|
|
if not self.query.related_updates and count == 1:
|
||
|
|
return
|
||
|
|
|
||
|
|
# We need to use a sub-select in the where clause to filter on things
|
||
|
|
# from other tables.
|
||
|
|
query = self.query.clone(klass=Query)
|
||
|
|
query.bump_prefix()
|
||
|
|
query.extra = {}
|
||
|
|
query.select = []
|
||
|
|
query.add_fields([query.model._meta.pk.name])
|
||
|
|
must_pre_select = count > 1 and not self.connection.features.update_can_self_select
|
||
|
|
|
||
|
|
# Now we adjust the current query: reset the where clause and get rid
|
||
|
|
# of all the tables we don't need (since they're in the sub-select).
|
||
|
|
self.query.where = self.query.where_class()
|
||
|
|
if self.query.related_updates or must_pre_select:
|
||
|
|
# Either we're using the idents in multiple update queries (so
|
||
|
|
# don't want them to change), or the db backend doesn't support
|
||
|
|
# selecting from the updating table (e.g. MySQL).
|
||
|
|
idents = []
|
||
|
|
for rows in query.get_compiler(self.using).execute_sql(MULTI):
|
||
|
|
idents.extend([r[0] for r in rows])
|
||
|
|
self.query.add_filter(('pk__in', idents))
|
||
|
|
self.query.related_ids = idents
|
||
|
|
else:
|
||
|
|
# The fast path. Filters and updates in one query.
|
||
|
|
self.query.add_filter(('pk__in', query))
|
||
|
|
for alias in self.query.tables[1:]:
|
||
|
|
self.query.alias_refcount[alias] = 0
|
||
|
|
|
||
|
|
class SQLAggregateCompiler(SQLCompiler):
|
||
|
|
def as_sql(self, qn=None):
|
||
|
|
"""
|
||
|
|
Creates the SQL for this query. Returns the SQL string and list of
|
||
|
|
parameters.
|
||
|
|
"""
|
||
|
|
if qn is None:
|
||
|
|
qn = self.quote_name_unless_alias
|
||
|
|
sql = ('SELECT %s FROM (%s) subquery' % (
|
||
|
|
', '.join([
|
||
|
|
aggregate.as_sql(qn, self.connection)
|
||
|
|
for aggregate in self.query.aggregate_select.values()
|
||
|
|
]),
|
||
|
|
self.query.subquery)
|
||
|
|
)
|
||
|
|
params = self.query.sub_params
|
||
|
|
return (sql, params)
|
||
|
|
|
||
|
|
class SQLDateCompiler(SQLCompiler):
|
||
|
|
def results_iter(self):
|
||
|
|
"""
|
||
|
|
Returns an iterator over the results from executing this query.
|
||
|
|
"""
|
||
|
|
resolve_columns = hasattr(self, 'resolve_columns')
|
||
|
|
if resolve_columns:
|
||
|
|
from django.db.models.fields import DateTimeField
|
||
|
|
fields = [DateTimeField()]
|
||
|
|
else:
|
||
|
|
from django.db.backends.util import typecast_timestamp
|
||
|
|
needs_string_cast = self.connection.features.needs_datetime_string_cast
|
||
|
|
|
||
|
|
offset = len(self.query.extra_select)
|
||
|
|
for rows in self.execute_sql(MULTI):
|
||
|
|
for row in rows:
|
||
|
|
date = row[offset]
|
||
|
|
if resolve_columns:
|
||
|
|
date = self.resolve_columns(row, fields)[offset]
|
||
|
|
elif needs_string_cast:
|
||
|
|
date = typecast_timestamp(str(date))
|
||
|
|
yield date
|
||
|
|
|
||
|
|
|
||
|
|
def empty_iter():
|
||
|
|
"""
|
||
|
|
Returns an iterator containing no results.
|
||
|
|
"""
|
||
|
|
yield iter([]).next()
|
||
|
|
|
||
|
|
|
||
|
|
def order_modified_iter(cursor, trim, sentinel):
|
||
|
|
"""
|
||
|
|
Yields blocks of rows from a cursor. We use this iterator in the special
|
||
|
|
case when extra output columns have been added to support ordering
|
||
|
|
requirements. We must trim those extra columns before anything else can use
|
||
|
|
the results, since they're only needed to make the SQL valid.
|
||
|
|
"""
|
||
|
|
for rows in iter((lambda: cursor.fetchmany(GET_ITERATOR_CHUNK_SIZE)),
|
||
|
|
sentinel):
|
||
|
|
yield [r[:-trim] for r in rows]
|