Dynamically Drop Table Constraints
-
Posted on June 17, 2009 by Derek Dieter
System generated constraints take on a naming convention of their own. Unfortunately the naming convention in production is rarely the same name in the uncontrolled environments. Using this script, you can dynamically drop all system generated constraints. It doesn’t go as far are re-creating them, however it’s a start. Just change the values of the @TableSchema and TableName variables below: [cc lang=”sql”] DECLARE @TableName varchar(100) DECLARE @TableSchema varchar(100) DECLARE @CountConst int DECLARE @default sysname DECLARE @SQLDropMe varchar(max) DECLARE @ColumnNames varchar(max) SET @TableSchema = ‘dbo’ SET @TableName = ’employees’ ——————————————— Store Existing Column Names SET @ColumnNames = SUBSTRING((SELECT ‘,’ + r.COLUMN_NAME FROM( SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = @TableSchema AND TABLE_NAME = @TableName ) r FOR XML PATH(”) ), 2, 8000) ——————————————— /Store Existing Column Names ——————————————— Insert contents into temp table EXEC (‘SELECT * INTO ‘ + @TableSchema + ‘.tmp01_’ + @TableName + ‘ FROM ‘ + @TableSchema + ‘.’ + @TableName) ——————————————— /Insert contents into temp table ——————————————— Drop all the constraints DECLARE @TableConstraints TABLE ( ID int IDENTITY(1,1) ,DefaultConst sysname ) INSERT INTO @TableConstraints ( DefaultConst ) SELECT object_name(default_object_id) FROM sys.columns WHERE object_id = object_id(@TableSchema + ‘.’ + @TableName) AND object_name(default_object_id) IS NOT NULL SET @CountConst = (SELECT MAX(ID) FROM @TableConstraints) WHILE @CountConst > 0 BEGIN SET @Default = (SELECT DefaultConst FROM @TableConstraints WHERE ID = @CountConst) SET @SQLDropMe = ‘ALTER TABLE ‘ + @TableSchema + ‘.’ + @TableName + ‘ DROP CONSTRAINT ‘ + @default SELECT @SQLDropMe –EXEC (@SQLDropMe) SET @CountConst = @CountConst – 1 END […]
Continue reading ...
