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@@ -12,3 +12,52 @@ class DatabaseSchemaEditor(myschema.DatabaseSchemaEditor):
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for idx_name in idx_names:
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self.execute(self._delete_constraint_sql(self.sql_delete_index, model, idx_name))
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super(DatabaseSchemaEditor, self).remove_field(model, field)
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+
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+ def column_sql(self, model, field, include_default=False):
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+ """
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+ Take a field and return its column definition.
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+ The field must already have had set_attributes_from_name() called.
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+ """
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+ # Get the column's type and use that as the basis of the SQL
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+ db_params = field.db_parameters(connection=self.connection)
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+ sql = db_params['type']
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+ params = []
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+ # Check for fields that aren't actually columns (e.g. M2M)
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+ if sql is None:
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+ return None, None
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+ # Work out nullability
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+ null = field.null
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+ # If we were told to include a default value, do so
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+ include_default = include_default and not self.skip_default(field)
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+ if include_default:
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+ default_value = self.effective_default(field)
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+ if default_value is not None:
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+ if self.connection.features.requires_literal_defaults:
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+ # Some databases can't take defaults as a parameter (oracle)
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+ # If this is the case, the individual schema backend should
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+ # implement prepare_default
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+ sql += " DEFAULT %s" % self.prepare_default(default_value)
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+ else:
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+ sql += " DEFAULT %s"
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+ params += [default_value]
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+ # Oracle treats the empty string ('') as null, so coerce the null
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+ # option whenever '' is a possible value.
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+ if (field.empty_strings_allowed and not field.primary_key and
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+ self.connection.features.interprets_empty_strings_as_nulls):
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+ null = True
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+ if null and not self.connection.features.implied_column_null:
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+ sql += " NULL"
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+ elif not null:
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+ sql += " NOT NULL"
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+ # Primary key/unique outputs
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+ if field.primary_key:
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+ sql += " PRIMARY KEY"
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+ # elif field.unique:
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+ # sql += " UNIQUE"
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+ # Optionally add the tablespace if it's an implicitly indexed column
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+ tablespace = field.db_tablespace or model._meta.db_tablespace
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+ if tablespace and self.connection.features.supports_tablespaces and field.unique:
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+ sql += " %s" % self.connection.ops.tablespace_sql(tablespace, inline=True)
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+ # Return the sql
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+ return sql, params
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+
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