用SQL查询表主键外键信息

SELECT  sysobjects.id objectId ,
        OBJECT_NAME(sysobjects.parent_obj) tableName ,
        sysobjects.name constraintName ,
        sysobjects.xtype AS constraintType ,
        syscolumns.name AS columnName
FROM    sysobjects
        INNER JOIN sysconstraints ON sysobjects.xtype IN ( 'C', 'F', 'PK',
                                                           'UQ', 'D' )
                                     AND sysobjects.id = sysconstraints.constid
        LEFT OUTER JOIN syscolumns ON sysconstraints.id = syscolumns.id
WHERE   OBJECT_NAME(sysobjects.parent_obj) = 'tableName'

（转自：鼠U猫）