SQL Server 2008-获取表约束
你可以帮我构build一个查询，检索所有表中的约束条件，每个表中的约束条数，还可以为没有任何约束的表显示NULL。 Thx提前！
这是我迄今为止：
Select SysObjects.[Name] As [Constraint Name] , Tab.[Name] as [Table Name], Col.[Name] As [Column Name] From SysObjects Inner Join (Select [Name],[ID] From SysObjects) As Tab On Tab.[ID] = Sysobjects.[Parent_Obj] Inner Join sysconstraints On sysconstraints.Constid = Sysobjects.[ID] Inner Join SysColumns Col On Col.[ColID] = sysconstraints.[ColID] And Col.[ID] = Tab.[ID] order by [Tab].[Name] 您应该使用当前的sys目录视图（如果您使用的是SQL Server 2005或更新版本 – 不build议使用 sysobjects视图，应该避免使用这些视图） – 请在此处查看有关目录视图的大量MSDN SQL Server联机丛书文档 。
有很多你可能感兴趣的观点：
-
sys.default_constraints列上的默认约束 -
sys.check_constraints列检查约束 - 关键约束的
sys.key_constraints（例如主键） -
sys.foreign_keys用于外键关系
和更多 – 检查出来！
你可以查询和join这些视图来获得所需的信息 – 例如，这将列出表，列和所有定义在它们上面的默认约束：
SELECT TableName = t.Name, ColumnName = c.Name, dc.Name, dc.definition FROM sys.tables t INNER JOIN sys.default_constraints dc ON t.object_id = dc.parent_object_id INNER JOIN sys.columns c ON dc.parent_object_id = c.object_id AND c.column_id = dc.parent_column_id ORDER BY t.Name
我使用以下查询检索SQL Server 2012中的约束信息，并且完美地工作。 我希望这对你有用。
SELECT tab.name AS [Table] ,tab.id AS [Table Id] ,constr.name AS [Constraint Name] ,constr.xtype AS [Constraint Type] ,CASE constr.xtype WHEN 'PK' THEN 'Primary Key' WHEN 'UQ' THEN 'Unique' ELSE '' END AS [Constraint Name] ,i.index_id AS [Index ID] ,ic.column_id AS [Column ID] ,clmns.name AS [Column Name] ,clmns.max_length AS [Column Max Length] ,clmns.precision AS [Column Precision] ,CASE WHEN clmns.is_nullable = 0 THEN 'NO' ELSE 'YES' END AS [Column Nullable] ,CASE WHEN clmns.is_identity = 0 THEN 'NO' ELSE 'YES' END AS [Column IS IDENTITY] FROM SysObjects AS tab INNER JOIN SysObjects AS constr ON(constr.parent_obj = tab.id AND constr.type = 'K') INNER JOIN sys.indexes AS i ON( (i.index_id > 0 and i.is_hypothetical = 0) AND (i.object_id=tab.id) AND i.name = constr.name ) INNER JOIN sys.index_columns AS ic ON (ic.column_id > 0 and (ic.key_ordinal > 0 or ic.partition_ordinal = 0 or ic.is_included_column != 0)) AND (ic.index_id=CAST(i.index_id AS int) AND ic.object_id=i.object_id) INNER JOIN sys.columns AS clmns ON clmns.object_id = ic.object_id and clmns.column_id = ic.column_id WHERE tab.xtype = 'U' ORDER BY tab.name
SELECT [oj].[name] [TableName], [ac].[name] [ColumnName], [dc].[name] [DefaultConstraintName], [dc].[definition] FROM sys.default_constraints [dc], sys.all_objects [oj], sys.all_columns [ac] WHERE ( ([oj].[type] IN ('u')) AND ([oj].[object_id] = [dc].[parent_object_id]) AND ([oj].[object_id] = [ac].[object_id]) AND ([dc].[parent_column_id] = [ac].[column_id]) )
我试图编辑由marc_s提供的答案 ，但由于某种原因未被接受。 它格式化sql更容易阅读，包括架构，并命名默认名称，以便这可以很容易地粘贴到其他代码。
SELECT SchemaName = s.Name, TableName = t.Name, ColumnName = c.Name, DefaultName = dc.Name, DefaultDefinition = dc.Definition FROM sys.schemas s JOIN sys.tables t on t.schema_id = s.schema_id JOIN sys.default_constraints dc on dc.parent_object_id = t.object_id JOIN sys.columns c on c.object_id = dc.parent_object_id and c.column_id = dc.parent_column_id ORDER BY s.Name, t.Name, c.name
你可以得到这个查询
独特的约束，
带值的默认约束，
与引用的表和列的外键
和主键约束。
Select C.*, (Select definition From sys.default_constraints Where object_id = C.object_id) As dk_definition, (Select definition From sys.check_constraints Where object_id = C.object_id) As ck_definition, (Select name From sys.objects Where object_id = D.referenced_object_id) As fk_table, (Select name From sys.columns Where column_id = D.parent_column_id And object_id = D.parent_object_id) As fk_col From sys.objects As C Left Join (Select * From sys.foreign_key_columns) As D On D.constraint_object_id = C.object_id Where C.parent_object_id = (Select object_id From sys.objects Where type = 'U' And name = 'Table Name Here');
