Current File : //opt/hc_python/lib64/python3.8/site-packages/mysql/connector/django/introspection.py
# MySQL Connector/Python - MySQL driver written in Python.
import re
from collections import namedtuple
import django
if django.VERSION >= (1, 8):
from django.db.backends.base.introspection import (
BaseDatabaseIntrospection, FieldInfo, TableInfo
)
else:
from django.db.backends import BaseDatabaseIntrospection
if django.VERSION >= (1, 6):
if django.VERSION < (1, 8):
from django.db.backends import FieldInfo
from django.utils.encoding import force_text
if django.VERSION >= (1, 7):
from django.utils.datastructures import OrderedSet
from mysql.connector.constants import FieldType
foreign_key_re = re.compile(r"\sCONSTRAINT `[^`]*` FOREIGN KEY \(`([^`]*)`\) "
r"REFERENCES `([^`]*)` \(`([^`]*)`\)")
if django.VERSION >= (1, 8):
FieldInfo = namedtuple('FieldInfo', FieldInfo._fields + ('extra',))
class DatabaseIntrospection(BaseDatabaseIntrospection):
data_types_reverse = {
FieldType.BLOB: 'TextField',
FieldType.DECIMAL: 'DecimalField',
FieldType.NEWDECIMAL: 'DecimalField',
FieldType.DATE: 'DateField',
FieldType.DATETIME: 'DateTimeField',
FieldType.DOUBLE: 'FloatField',
FieldType.FLOAT: 'FloatField',
FieldType.INT24: 'IntegerField',
FieldType.LONG: 'IntegerField',
FieldType.LONGLONG: 'BigIntegerField',
FieldType.SHORT: (
'IntegerField' if django.VERSION < (1, 8) else 'SmallIntegerField'
),
FieldType.STRING: 'CharField',
FieldType.TIME: 'TimeField',
FieldType.TIMESTAMP: 'DateTimeField',
FieldType.TINY: 'IntegerField',
FieldType.TINY_BLOB: 'TextField',
FieldType.MEDIUM_BLOB: 'TextField',
FieldType.LONG_BLOB: 'TextField',
FieldType.VAR_STRING: 'CharField',
}
def get_field_type(self, data_type, description):
field_type = super(DatabaseIntrospection, self).get_field_type(
data_type, description)
if (field_type == 'IntegerField'
and 'auto_increment' in description.extra):
return 'AutoField'
return field_type
def get_table_list(self, cursor):
"""Returns a list of table names in the current database."""
cursor.execute("SHOW FULL TABLES")
if django.VERSION >= (1, 8):
return [
TableInfo(row[0], {'BASE TABLE': 't', 'VIEW': 'v'}.get(row[1]))
for row in cursor.fetchall()
]
else:
return [row[0] for row in cursor.fetchall()]
if django.VERSION >= (1, 8):
def get_table_description(self, cursor, table_name):
"""
Returns a description of the table, with the DB-API
cursor.description interface."
"""
# - information_schema database gives more accurate results for
# some figures:
# - varchar length returned by cursor.description is an internal
# length, not visible length (#5725)
# - precision and scale (for decimal fields) (#5014)
# - auto_increment is not available in cursor.description
InfoLine = namedtuple(
'InfoLine',
'col_name data_type max_len num_prec num_scale extra'
)
cursor.execute("""
SELECT column_name, data_type, character_maximum_length,
numeric_precision, numeric_scale, extra
FROM information_schema.columns
WHERE table_name = %s AND table_schema = DATABASE()""",
[table_name])
field_info = dict(
(line[0], InfoLine(*line)) for line in cursor.fetchall()
)
cursor.execute("SELECT * FROM %s LIMIT 1"
% self.connection.ops.quote_name(table_name))
to_int = lambda i: int(i) if i is not None else i
fields = []
for line in cursor.description:
col_name = force_text(line[0])
fields.append(
FieldInfo(*((col_name,)
+ line[1:3]
+ (to_int(field_info[col_name].max_len)
or line[3],
to_int(field_info[col_name].num_prec)
or line[4],
to_int(field_info[col_name].num_scale)
or line[5])
+ (line[6],)
+ (field_info[col_name].extra,)))
)
return fields
else:
def get_table_description(self, cursor, table_name):
"""
Returns a description of the table, with the DB-API
cursor.description interface.
"""
# varchar length returned by cursor.description is an internal
# length not visible length (#5725), use information_schema database
# to fix this
cursor.execute(
"SELECT column_name, character_maximum_length "
"FROM INFORMATION_SCHEMA.COLUMNS "
"WHERE table_name = %s AND table_schema = DATABASE() "
"AND character_maximum_length IS NOT NULL", [table_name])
length_map = dict(cursor.fetchall())
# Also getting precision and scale from
# information_schema (see #5014)
cursor.execute(
"SELECT column_name, numeric_precision, numeric_scale FROM "
"INFORMATION_SCHEMA.COLUMNS WHERE table_name = %s AND "
"table_schema = DATABASE() AND data_type='decimal'",
[table_name])
numeric_map = dict((line[0], tuple([int(n) for n in line[1:]]))
for line in cursor.fetchall())
cursor.execute("SELECT * FROM {0} LIMIT 1".format(
self.connection.ops.quote_name(table_name)))
if django.VERSION >= (1, 6):
return [FieldInfo(*((force_text(line[0]),)
+ line[1:3]
+ (length_map.get(line[0], line[3]),)
+ numeric_map.get(line[0], line[4:6])
+ (line[6],)))
for line in cursor.description]
else:
return [
line[:3] + (length_map.get(line[0], line[3]),) + line[4:]
for line in cursor.description
]
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.
"""
constraints = self.get_key_columns(cursor, table_name)
relations = {}
if django.VERSION >= (1, 8):
for my_fieldname, other_table, other_field in constraints:
relations[my_fieldname] = (other_field, other_table)
return relations
else:
my_field_dict = self._name_to_index(cursor, table_name)
for my_fieldname, other_table, other_field in constraints:
other_field_index = self._name_to_index(
cursor, other_table)[other_field]
my_field_index = my_field_dict[my_fieldname]
relations[my_field_index] = (other_field_index, other_table)
return relations
def get_key_columns(self, cursor, table_name):
"""
Returns a list of (column_name, referenced_table_name,
referenced_column_name) for all key columns in given table.
"""
key_columns = []
cursor.execute(
"SELECT column_name, referenced_table_name, referenced_column_name "
"FROM information_schema.key_column_usage "
"WHERE table_name = %s "
"AND table_schema = DATABASE() "
"AND referenced_table_name IS NOT NULL "
"AND referenced_column_name IS NOT NULL", [table_name])
key_columns.extend(cursor.fetchall())
return key_columns
def get_indexes(self, cursor, table_name):
cursor.execute("SHOW INDEX FROM {0}"
"".format(self.connection.ops.quote_name(table_name)))
# Do a two-pass search for indexes: on first pass check which indexes
# are multicolumn, on second pass check which single-column indexes
# are present.
rows = list(cursor.fetchall())
multicol_indexes = set()
for row in rows:
if row[3] > 1:
multicol_indexes.add(row[2])
indexes = {}
for row in rows:
if row[2] in multicol_indexes:
continue
if row[4] not in indexes:
indexes[row[4]] = {'primary_key': False, 'unique': False}
# It's possible to have the unique and PK constraints in
# separate indexes.
if row[2] == 'PRIMARY':
indexes[row[4]]['primary_key'] = True
if not row[1]:
indexes[row[4]]['unique'] = True
return indexes
def get_primary_key_column(self, cursor, table_name):
"""
Returns the name of the primary key column for the given table
"""
# Django 1.6
for column in self.get_indexes(cursor, table_name).items():
if column[1]['primary_key']:
return column[0]
return None
def get_storage_engine(self, cursor, table_name):
"""
Retrieves the storage engine for a given table. Returns the default
storage engine if the table doesn't exist.
"""
cursor.execute(
"SELECT engine "
"FROM information_schema.tables "
"WHERE table_name = %s", [table_name])
result = cursor.fetchone()
if not result:
return self.connection.features.mysql_storage_engine
return result[0]
def get_constraints(self, cursor, table_name):
"""
Retrieves any constraints or keys (unique, pk, fk, check, index) across
one or more columns.
"""
# Django 1.7
constraints = {}
# Get the actual constraint names and columns
name_query = (
"SELECT kc.`constraint_name`, kc.`column_name`, "
"kc.`referenced_table_name`, kc.`referenced_column_name` "
"FROM information_schema.key_column_usage AS kc "
"WHERE "
"kc.table_schema = %s AND "
"kc.table_name = %s"
)
cursor.execute(name_query, [self.connection.settings_dict['NAME'],
table_name])
for constraint, column, ref_table, ref_column in cursor.fetchall():
if constraint not in constraints:
constraints[constraint] = {
'columns': OrderedSet(),
'primary_key': False,
'unique': False,
'index': False,
'check': False,
'foreign_key': (
(ref_table, ref_column) if ref_column else None,
)
}
constraints[constraint]['columns'].add(column)
# Now get the constraint types
type_query = """
SELECT c.constraint_name, c.constraint_type
FROM information_schema.table_constraints AS c
WHERE
c.table_schema = %s AND
c.table_name = %s
"""
cursor.execute(type_query, [self.connection.settings_dict['NAME'],
table_name])
for constraint, kind in cursor.fetchall():
if kind.lower() == "primary key":
constraints[constraint]['primary_key'] = True
constraints[constraint]['unique'] = True
elif kind.lower() == "unique":
constraints[constraint]['unique'] = True
# Now add in the indexes
cursor.execute("SHOW INDEX FROM %s" % self.connection.ops.quote_name(
table_name))
for table, non_unique, index, colseq, column in [x[:5] for x in
cursor.fetchall()]:
if index not in constraints:
constraints[index] = {
'columns': OrderedSet(),
'primary_key': False,
'unique': False,
'index': True,
'check': False,
'foreign_key': None,
}
constraints[index]['index'] = True
constraints[index]['columns'].add(column)
# Convert the sorted sets to lists
for constraint in constraints.values():
constraint['columns'] = list(constraint['columns'])
return constraints
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