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