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98 lines
4.2 KiB
98 lines
4.2 KiB
from django.db.backends import BaseDatabaseIntrospection |
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from MySQLdb import ProgrammingError, OperationalError |
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from MySQLdb.constants import FIELD_TYPE |
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import re |
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foreign_key_re = re.compile(r"\sCONSTRAINT `[^`]*` FOREIGN KEY \(`([^`]*)`\) REFERENCES `([^`]*)` \(`([^`]*)`\)") |
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class DatabaseIntrospection(BaseDatabaseIntrospection): |
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data_types_reverse = { |
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FIELD_TYPE.BLOB: 'TextField', |
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FIELD_TYPE.CHAR: 'CharField', |
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FIELD_TYPE.DECIMAL: 'DecimalField', |
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FIELD_TYPE.NEWDECIMAL: 'DecimalField', |
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FIELD_TYPE.DATE: 'DateField', |
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FIELD_TYPE.DATETIME: 'DateTimeField', |
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FIELD_TYPE.DOUBLE: 'FloatField', |
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FIELD_TYPE.FLOAT: 'FloatField', |
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FIELD_TYPE.INT24: 'IntegerField', |
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FIELD_TYPE.LONG: 'IntegerField', |
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FIELD_TYPE.LONGLONG: 'IntegerField', |
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FIELD_TYPE.SHORT: 'IntegerField', |
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FIELD_TYPE.STRING: 'CharField', |
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FIELD_TYPE.TIMESTAMP: 'DateTimeField', |
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FIELD_TYPE.TINY: 'IntegerField', |
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FIELD_TYPE.TINY_BLOB: 'TextField', |
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FIELD_TYPE.MEDIUM_BLOB: 'TextField', |
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FIELD_TYPE.LONG_BLOB: 'TextField', |
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FIELD_TYPE.VAR_STRING: 'CharField', |
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} |
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def get_table_list(self, cursor): |
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"Returns a list of table names in the current database." |
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cursor.execute("SHOW TABLES") |
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return [row[0] for row in cursor.fetchall()] |
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def get_table_description(self, 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" % self.connection.ops.quote_name(table_name)) |
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return cursor.description |
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def _name_to_index(self, cursor, table_name): |
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""" |
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Returns a dictionary of {field_name: field_index} for the given table. |
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Indexes are 0-based. |
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""" |
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return dict([(d[0], i) for i, d in enumerate(self.get_table_description(cursor, table_name))]) |
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def get_relations(self, 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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my_field_dict = self._name_to_index(cursor, table_name) |
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constraints = [] |
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relations = {} |
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try: |
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# This should work for MySQL 5.0. |
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cursor.execute(""" |
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SELECT column_name, referenced_table_name, referenced_column_name |
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FROM information_schema.key_column_usage |
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WHERE table_name = %s |
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AND table_schema = DATABASE() |
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AND referenced_table_name IS NOT NULL |
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AND referenced_column_name IS NOT NULL""", [table_name]) |
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constraints.extend(cursor.fetchall()) |
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except (ProgrammingError, OperationalError): |
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# Fall back to "SHOW CREATE TABLE", for previous MySQL versions. |
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# Go through all constraints and save the equal matches. |
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cursor.execute("SHOW CREATE TABLE %s" % self.connection.ops.quote_name(table_name)) |
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for row in cursor.fetchall(): |
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pos = 0 |
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while True: |
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match = foreign_key_re.search(row[1], pos) |
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if match == None: |
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break |
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pos = match.end() |
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constraints.append(match.groups()) |
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for my_fieldname, other_table, other_field in constraints: |
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other_field_index = self._name_to_index(cursor, other_table)[other_field] |
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my_field_index = my_field_dict[my_fieldname] |
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relations[my_field_index] = (other_field_index, other_table) |
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return relations |
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def get_indexes(self, 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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cursor.execute("SHOW INDEX FROM %s" % self.connection.ops.quote_name(table_name)) |
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indexes = {} |
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for row in cursor.fetchall(): |
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indexes[row[4]] = {'primary_key': (row[2] == 'PRIMARY'), 'unique': not bool(row[1])} |
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return indexes |
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