Fixed #23538 -- Added SchemaEditor for MySQL GIS.

Thanks Claude Paroz for suggestions and review.
This commit is contained in:
Tim Graham 2014-09-23 14:13:59 -04:00
parent 215aa4f53b
commit 74e7f91e6d
8 changed files with 132 additions and 4 deletions

View File

@ -6,6 +6,7 @@ from django.contrib.gis.db.backends.base import BaseSpatialFeatures
from django.contrib.gis.db.backends.mysql.creation import MySQLCreation
from django.contrib.gis.db.backends.mysql.introspection import MySQLIntrospection
from django.contrib.gis.db.backends.mysql.operations import MySQLOperations
from django.contrib.gis.db.backends.mysql.schema import MySQLGISSchemaEditor
class DatabaseFeatures(BaseSpatialFeatures, MySQLDatabaseFeatures):
@ -25,3 +26,7 @@ class DatabaseWrapper(MySQLDatabaseWrapper):
self.creation = MySQLCreation(self)
self.ops = MySQLOperations(self)
self.introspection = MySQLIntrospection(self)
def schema_editor(self, *args, **kwargs):
"Returns a new instance of this backend's SchemaEditor"
return MySQLGISSchemaEditor(self, *args, **kwargs)

View File

@ -31,3 +31,11 @@ class MySQLIntrospection(DatabaseIntrospection):
cursor.close()
return field_type, field_params
def supports_spatial_index(self, cursor, table_name):
# Supported with MyISAM, or InnoDB on MySQL 5.7.5+
storage_engine = self.get_storage_engine(cursor, table_name)
return (
(storage_engine == 'InnoDB' and self.connection.mysql_version >= (5, 7, 5)) or
storage_engine == 'MyISAM'
)

View File

@ -0,0 +1,70 @@
import logging
from django.contrib.gis.db.models.fields import GeometryField
from django.db.utils import OperationalError
from django.db.backends.mysql.schema import DatabaseSchemaEditor
logger = logging.getLogger('django.contrib.gis')
class MySQLGISSchemaEditor(DatabaseSchemaEditor):
sql_add_spatial_index = 'CREATE SPATIAL INDEX %(index)s ON %(table)s(%(column)s)'
sql_drop_spatial_index = 'DROP INDEX %(index)s ON %(table)s'
def __init__(self, *args, **kwargs):
super(MySQLGISSchemaEditor, self).__init__(*args, **kwargs)
self.geometry_sql = []
def column_sql(self, model, field, include_default=False):
column_sql = super(MySQLGISSchemaEditor, self).column_sql(model, field, include_default)
# MySQL doesn't support spatial indexes on NULL columns
if isinstance(field, GeometryField) and field.spatial_index and not field.null:
qn = self.connection.ops.quote_name
db_table = model._meta.db_table
self.geometry_sql.append(
self.sql_add_spatial_index % {
'index': qn(self._create_spatial_index_name(model, field)),
'table': qn(db_table),
'column': qn(field.column),
}
)
return column_sql
def create_model(self, model):
super(MySQLGISSchemaEditor, self).create_model(model)
self.create_spatial_indexes()
def add_field(self, model, field):
super(MySQLGISSchemaEditor, self).add_field(model, field)
self.create_spatial_indexes()
def remove_field(self, model, field):
if isinstance(field, GeometryField) and field.spatial_index:
qn = self.connection.ops.quote_name
sql = self.sql_drop_spatial_index % {
'index': qn(self._create_spatial_index_name(model, field)),
'table': qn(model._meta.db_table),
}
try:
self.execute(sql)
except OperationalError:
logger.error(
"Couldn't remove spatial index: %s (may be expected "
"if your storage engine doesn't support them)." % sql
)
super(MySQLGISSchemaEditor, self).remove_field(model, field)
def _create_spatial_index_name(self, model, field):
return '%s_%s_id' % (model._meta.db_table, field.column)
def create_spatial_indexes(self):
for sql in self.geometry_sql:
try:
self.execute(sql)
except OperationalError:
logger.error(
"Cannot create SPATIAL INDEX %s. Only MyISAM and (as of "
"MySQL 5.7.5) InnoDB support them." % sql
)
self.geometry_sql = []

View File

@ -53,3 +53,12 @@ class SpatiaLiteIntrospection(DatabaseIntrospection):
cursor.close()
return field_type, field_params
def get_indexes(self, cursor, table_name):
indexes = super(SpatiaLiteIntrospection, self).get_indexes(cursor, table_name)
cursor.execute('SELECT f_geometry_column '
'FROM geometry_columns '
'WHERE f_table_name=%s AND spatial_index_enabled=1', (table_name,))
for row in cursor.fetchall():
indexes[row[0]] = {'primary_key': False, 'unique': False}
return indexes

View File

@ -12,7 +12,7 @@ class Migration(migrations.Migration):
fields=[
('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
('name', models.CharField(max_length=100, unique=True)),
('geom', django.contrib.gis.db.models.fields.MultiPolygonField(srid=4326, null=True)),
('geom', django.contrib.gis.db.models.fields.MultiPolygonField(srid=4326)),
],
options={
},
@ -25,7 +25,7 @@ class Migration(migrations.Migration):
('neighborhood', models.ForeignKey(to='gis.Neighborhood', to_field='id', null=True)),
('address', models.CharField(max_length=100)),
('zip_code', models.IntegerField(null=True, blank=True)),
('geom', django.contrib.gis.db.models.fields.PointField(srid=4326, null=True, geography=True)),
('geom', django.contrib.gis.db.models.fields.PointField(srid=4326, geography=True)),
],
options={
},

View File

@ -1,5 +1,6 @@
from __future__ import unicode_literals
from django.contrib.gis.tests.utils import mysql
from django.db import connection, migrations, models
from django.db.migrations.migration import Migration
from django.db.migrations.state import ProjectState
@ -45,7 +46,7 @@ class OperationTests(TransactionTestCase):
[
("id", models.AutoField(primary_key=True)),
('name', models.CharField(max_length=100, unique=True)),
('geom', fields.MultiPolygonField(srid=4326, null=True)),
('geom', fields.MultiPolygonField(srid=4326)),
],
)]
return self.apply_operations('gis', ProjectState(), operations)
@ -58,7 +59,7 @@ class OperationTests(TransactionTestCase):
operation = migrations.AddField(
"Neighborhood",
"path",
fields.LineStringField(srid=4326, null=True, blank=True),
fields.LineStringField(srid=4326),
)
new_state = project_state.clone()
operation.state_forwards("gis", new_state)
@ -74,6 +75,11 @@ class OperationTests(TransactionTestCase):
2
)
if self.has_spatial_indexes:
with connection.cursor() as cursor:
indexes = connection.introspection.get_indexes(cursor, "gis_neighborhood")
self.assertIn('path', indexes)
def test_remove_gis_field(self):
"""
Tests the RemoveField operation with a GIS-enabled column.
@ -93,3 +99,20 @@ class OperationTests(TransactionTestCase):
GeometryColumns.objects.filter(**{GeometryColumns.table_name_col(): "gis_neighborhood"}).count(),
0
)
def test_create_model_spatial_index(self):
self.current_state = self.set_up_test_model()
if not self.has_spatial_indexes:
self.skipTest("No support for Spatial indexes")
with connection.cursor() as cursor:
indexes = connection.introspection.get_indexes(cursor, "gis_neighborhood")
self.assertIn('geom', indexes)
@property
def has_spatial_indexes(self):
if mysql:
with connection.cursor() as cursor:
return connection.introspection.supports_spatial_index(cursor, "gis_neighborhood")
return True

View File

@ -127,6 +127,16 @@ class DatabaseIntrospection(BaseDatabaseIntrospection):
indexes[row[4]]['unique'] = True
return indexes
def get_storage_engine(self, cursor, table_name):
"""
Retrieves the storage engine for a given table.
"""
cursor.execute(
"SELECT engine "
"FROM information_schema.tables "
"WHERE table_name = %s", [table_name])
return cursor.fetchone()[0]
def get_constraints(self, cursor, table_name):
"""
Retrieves any constraints or keys (unique, pk, fk, check, index) across one or more columns.

View File

@ -73,3 +73,6 @@ Bugfixes
* Fixed bug in migrations that prevented foreign key constraints to unmanaged
models with a custom primary key (:ticket:`23415`).
* Added ``SchemaEditor`` for MySQL GIS backend so that spatial indexes will be
created for apps with migrations (:ticket:`23538`).