86 lines
3.2 KiB
Python
86 lines
3.2 KiB
Python
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from django.db import transaction
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from django.db.backends.postgresql.base import quote_name
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def get_table_list(cursor):
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"Returns a list of table names in the current database."
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cursor.execute("""
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SELECT c.relname
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FROM pg_catalog.pg_class c
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LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
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WHERE c.relkind IN ('r', 'v', '')
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AND n.nspname NOT IN ('pg_catalog', 'pg_toast')
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AND pg_catalog.pg_table_is_visible(c.oid)""")
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return [row[0] for row in cursor.fetchall()]
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def get_table_description(cursor, table_name):
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"Returns a description of the table, with the DB-API cursor.description interface."
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cursor.execute("SELECT * FROM %s LIMIT 1" % quote_name(table_name))
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return cursor.description
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def get_relations(cursor, table_name):
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"""
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Returns a dictionary of {field_index: (field_index_other_table, other_table)}
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representing all relationships to the given table. Indexes are 0-based.
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"""
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cursor.execute("""
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SELECT con.conkey, con.confkey, c2.relname
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FROM pg_constraint con, pg_class c1, pg_class c2
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WHERE c1.oid = con.conrelid
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AND c2.oid = con.confrelid
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AND c1.relname = %s
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AND con.contype = 'f'""", [table_name])
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relations = {}
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for row in cursor.fetchall():
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try:
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# row[0] and row[1] are like "{2}", so strip the curly braces.
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relations[int(row[0][1:-1]) - 1] = (int(row[1][1:-1]) - 1, row[2])
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except ValueError:
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continue
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return relations
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def get_indexes(cursor, table_name):
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"""
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Returns a dictionary of fieldname -> infodict for the given table,
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where each infodict is in the format:
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{'primary_key': boolean representing whether it's the primary key,
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'unique': boolean representing whether it's a unique index}
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"""
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# Get the table description because we only have the column indexes, and we
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# need the column names.
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desc = get_table_description(cursor, table_name)
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# This query retrieves each index on the given table.
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cursor.execute("""
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SELECT idx.indkey, idx.indisunique, idx.indisprimary
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FROM pg_catalog.pg_class c, pg_catalog.pg_class c2,
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pg_catalog.pg_index idx
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WHERE c.oid = idx.indrelid
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AND idx.indexrelid = c2.oid
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AND c.relname = %s""", [table_name])
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indexes = {}
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for row in cursor.fetchall():
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# row[0] (idx.indkey) is stored in the DB as an array. It comes out as
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# a string of space-separated integers. This designates the field
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# indexes (1-based) of the fields that have indexes on the table.
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# Here, we skip any indexes across multiple fields.
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if ' ' in row[0]:
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continue
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col_name = desc[int(row[0])-1][0]
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indexes[col_name] = {'primary_key': row[2], 'unique': row[1]}
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return indexes
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# Maps type codes to Django Field types.
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DATA_TYPES_REVERSE = {
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16: 'BooleanField',
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21: 'SmallIntegerField',
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23: 'IntegerField',
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25: 'TextField',
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869: 'IPAddressField',
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1043: 'CharField',
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1082: 'DateField',
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1083: 'TimeField',
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1114: 'DateTimeField',
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1184: 'DateTimeField',
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1266: 'TimeField',
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1700: 'FloatField',
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}
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