Clean document references
This has the advantage that we can inform the user if a document
could not be found.
Patch by: Sverre Rabbelier
from django.db.backends import BaseDatabaseIntrospection
import cx_Oracle
import re
foreign_key_re = re.compile(r"\sCONSTRAINT `[^`]*` FOREIGN KEY \(`([^`]*)`\) REFERENCES `([^`]*)` \(`([^`]*)`\)")
class DatabaseIntrospection(BaseDatabaseIntrospection):
# Maps type objects to Django Field types.
data_types_reverse = {
cx_Oracle.CLOB: 'TextField',
cx_Oracle.DATETIME: 'DateTimeField',
cx_Oracle.FIXED_CHAR: 'CharField',
cx_Oracle.NCLOB: 'TextField',
cx_Oracle.NUMBER: 'DecimalField',
cx_Oracle.STRING: 'CharField',
cx_Oracle.TIMESTAMP: 'DateTimeField',
}
def get_table_list(self, cursor):
"Returns a list of table names in the current database."
cursor.execute("SELECT TABLE_NAME FROM USER_TABLES")
return [row[0].upper() for row in cursor.fetchall()]
def get_table_description(self, cursor, table_name):
"Returns a description of the table, with the DB-API cursor.description interface."
cursor.execute("SELECT * FROM %s WHERE ROWNUM < 2" % self.connection.ops.quote_name(table_name))
return cursor.description
def table_name_converter(self, name):
"Table name comparison is case insensitive under Oracle"
return name.upper()
def _name_to_index(self, cursor, table_name):
"""
Returns a dictionary of {field_name: field_index} for the given table.
Indexes are 0-based.
"""
return dict([(d[0], i) for i, d in enumerate(self.get_table_description(cursor, table_name))])
def get_relations(self, cursor, table_name):
"""
Returns a dictionary of {field_index: (field_index_other_table, other_table)}
representing all relationships to the given table. Indexes are 0-based.
"""
cursor.execute("""
SELECT ta.column_id - 1, tb.table_name, tb.column_id - 1
FROM user_constraints, USER_CONS_COLUMNS ca, USER_CONS_COLUMNS cb,
user_tab_cols ta, user_tab_cols tb
WHERE user_constraints.table_name = %s AND
ta.table_name = %s AND
ta.column_name = ca.column_name AND
ca.table_name = %s AND
user_constraints.constraint_name = ca.constraint_name AND
user_constraints.r_constraint_name = cb.constraint_name AND
cb.table_name = tb.table_name AND
cb.column_name = tb.column_name AND
ca.position = cb.position""", [table_name, table_name, table_name])
relations = {}
for row in cursor.fetchall():
relations[row[0]] = (row[2], row[1])
return relations
def get_indexes(self, cursor, table_name):
"""
Returns a dictionary of fieldname -> infodict for the given table,
where each infodict is in the format:
{'primary_key': boolean representing whether it's the primary key,
'unique': boolean representing whether it's a unique index}
"""
# This query retrieves each index on the given table, including the
# first associated field name
# "We were in the nick of time; you were in great peril!"
sql = """
WITH primarycols AS (
SELECT user_cons_columns.table_name, user_cons_columns.column_name, 1 AS PRIMARYCOL
FROM user_cons_columns, user_constraints
WHERE user_cons_columns.constraint_name = user_constraints.constraint_name AND
user_constraints.constraint_type = 'P' AND
user_cons_columns.table_name = %s),
uniquecols AS (
SELECT user_ind_columns.table_name, user_ind_columns.column_name, 1 AS UNIQUECOL
FROM user_indexes, user_ind_columns
WHERE uniqueness = 'UNIQUE' AND
user_indexes.index_name = user_ind_columns.index_name AND
user_ind_columns.table_name = %s)
SELECT allcols.column_name, primarycols.primarycol, uniquecols.UNIQUECOL
FROM (SELECT column_name FROM primarycols UNION SELECT column_name FROM
uniquecols) allcols,
primarycols, uniquecols
WHERE allcols.column_name = primarycols.column_name (+) AND
allcols.column_name = uniquecols.column_name (+)
"""
cursor.execute(sql, [table_name, table_name])
indexes = {}
for row in cursor.fetchall():
# row[1] (idx.indkey) is stored in the DB as an array. It comes out as
# a string of space-separated integers. This designates the field
# indexes (1-based) of the fields that have indexes on the table.
# Here, we skip any indexes across multiple fields.
indexes[row[0]] = {'primary_key': row[1], 'unique': row[2]}
return indexes