86 lines
3.5 KiB
Python
86 lines
3.5 KiB
Python
import psycopg2
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from django.db.backends.base.schema import BaseDatabaseSchemaEditor
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class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
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sql_create_sequence = "CREATE SEQUENCE %(sequence)s"
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sql_delete_sequence = "DROP SEQUENCE IF EXISTS %(sequence)s CASCADE"
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sql_set_sequence_max = "SELECT setval('%(sequence)s', MAX(%(column)s)) FROM %(table)s"
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sql_create_varchar_index = "CREATE INDEX %(name)s ON %(table)s (%(columns)s varchar_pattern_ops)%(extra)s"
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sql_create_text_index = "CREATE INDEX %(name)s ON %(table)s (%(columns)s text_pattern_ops)%(extra)s"
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def quote_value(self, value):
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return psycopg2.extensions.adapt(value)
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def _model_indexes_sql(self, model):
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output = super(DatabaseSchemaEditor, self)._model_indexes_sql(model)
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if not model._meta.managed or model._meta.proxy or model._meta.swapped:
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return output
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for field in model._meta.local_fields:
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db_type = field.db_type(connection=self.connection)
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if db_type is not None and (field.db_index or field.unique):
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# Fields with database column types of `varchar` and `text` need
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# a second index that specifies their operator class, which is
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# needed when performing correct LIKE queries outside the
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# C locale. See #12234.
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if db_type.startswith('varchar'):
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output.append(self._create_index_sql(
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model, [field], suffix='_like', sql=self.sql_create_varchar_index))
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elif db_type.startswith('text'):
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output.append(self._create_index_sql(
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model, [field], suffix='_like', sql=self.sql_create_text_index))
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return output
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def _alter_column_type_sql(self, table, column, type):
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"""
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Makes ALTER TYPE with SERIAL make sense.
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"""
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if type.lower() == "serial":
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sequence_name = "%s_%s_seq" % (table, column)
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return (
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(
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self.sql_alter_column_type % {
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"column": self.quote_name(column),
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"type": "integer",
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},
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[],
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),
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[
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(
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self.sql_delete_sequence % {
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"sequence": sequence_name,
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},
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[],
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),
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(
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self.sql_create_sequence % {
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"sequence": sequence_name,
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},
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[],
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),
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(
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self.sql_alter_column % {
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"table": table,
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"changes": self.sql_alter_column_default % {
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"column": column,
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"default": "nextval('%s')" % sequence_name,
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}
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},
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[],
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),
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(
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self.sql_set_sequence_max % {
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"table": table,
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"column": column,
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"sequence": sequence_name,
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},
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[],
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),
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],
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)
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else:
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return super(DatabaseSchemaEditor, self)._alter_column_type_sql(table, column, type)
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