這里有我自己的版本，它會(huì)刪除所有依賴的約束 – 默認(rèn)約束 (如果存在的話)和所有受影響的檢查約束 (正如SQL標(biāo)準(zhǔn)似乎暗示的一樣，和其他一些數(shù)據(jù)庫(kù)似乎是這樣)

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：在上面的代碼中， TableName和ColumnToBeDropped都會(huì)出現(xiàn)兩次)

這通過(guò)構(gòu)build單個(gè)ALTER TABLE TableName DROP CONSTRAINT c1, ..., COLUMN ColumnToBeDropped并執(zhí)行它。

總結(jié)

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