了解网站开发的背景,物联网应用有哪些,广州市建设厅网站首页,衡阳商城网站建设这里有我自己的版本#xff0c;它会删除所有依赖的约束 – 默认约束 (如果存在的话)和所有受影响的检查约束 (正如SQL标准似乎暗示的一样#xff0c;和其他一些数据库似乎是这样)declare constraints varchar(4000); declare sql varchar(4000); with table_id_column_positi…这里有我自己的版本它会删除所有依赖的约束 – 默认约束 (如果存在的话)和所有受影响的检查约束 (正如SQL标准似乎暗示的一样和其他一些数据库似乎是这样)declare constraints varchar(4000); declare sql varchar(4000); with table_id_column_position as ( select object_id table_id, column_id column_position from sys.columns where object_id is not null and object_id object_id(TableName) and name ColumnToBeDropped ) select constraints coalesce(constraints, constraint ) [ name ], from sysobjects where ( -- is CHECK constraint type C -- dependeds on the column and id is not null and id in ( select object_id --, object_name(object_id) from sys.sql_dependencies, table_id_column_position where object_id is not null and referenced_major_id table_id_column_position.table_id and referenced_minor_id table_id_column_position.column_position ) ) OR ( -- is DEFAULT constraint type D and id is not null and id in ( select object_id from sys.default_constraints, table_id_column_position where object_id is not null and parent_object_id table_id_column_position.table_id and parent_column_id table_id_column_position.column_position ) ); set sql alter table TableName drop coalesce(constraints, ) column ColumnToBeDropped; exec sql(注意在上面的代码中 TableName和ColumnToBeDropped都会出现两次)这通过构build单个ALTER TABLE TableName DROP CONSTRAINT c1, ..., COLUMN ColumnToBeDropped并执行它。
