Question

我的表中有一列有默认值约束'DF_DOC_DMA_PLACE_1_dma_id'

我想删除该列，但首先我需要删除该约束。问题是该表存在于许多数据库中，其中一些数据库不存在约束。如何首先检查约束是否存在，然后将其删除？

我知道INFORMATION_SCHEMA中的视图但我找不到具有此约束的视图？你能告诉我默认值约束在哪里吗？感谢

Answer 1

请使用以下查询查找每个表的默认约束。

SELECT OBJECT_NAME(OBJECT_ID) AS NameofConstraint,
SCHEMA_NAME(schema_id) AS SchemaName,
OBJECT_NAME(parent_object_id) AS TableName,
type_desc AS ConstraintType
FROM sys.objects
WHERE type_desc = 'DEFAULT_CONSTRAINT'

Answer 2

根据你会发现的内容尝试一些......

select t.name as 'table', c.[name] as 'column' ,dc.[name],dc.[definition]
from sys.tables as t
join sys.columns as c on (c.[object_id] = t.[object_id])
join sys.default_constraints as dc on (dc.[object_id] = c.[default_object_id])

SQL默认值约束INFORMATION_SCHEMA

2 个答案: