SQL 2008 – INFORMATION_SCHEMA视图中的外键约束

我正在编写ac＃unit test，它针对目标数据库validationORM类的字符串属性，始终是SQL 2008，以及数据映射到的类。

检查指定的外键在DB中是否有效很容易：

static private bool ConstraintExsits(string table, string column, ConstraintType constraintType) { string constraintTypeWhereClause; switch (constraintType) { case ConstraintType.PrimaryKey: constraintTypeWhereClause = "PRIMARY KEY"; break; case ConstraintType.ForeignKey: constraintTypeWhereClause = "FOREIGN KEY"; break; default: throw new ArgumentOutOfRangeException("constraintType"); } var cmd = new SqlCommand( @"SELECT a.CONSTRAINT_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS a JOIN INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE b on a.CONSTRAINT_NAME = b.CONSTRAINT_NAME WHERE a.TABLE_NAME = @table AND b.COLUMN_NAME = @column AND a.CONSTRAINT_TYPE = '" + constraintTypeWhereClause + "'", Connection); cmd.Parameters.AddWithValue("@table", table.Trim('[').Trim(']')); cmd.Parameters.AddWithValue("@column", column.Trim('[').Trim(']')); return !string.IsNullOrEmpty((string)cmd.ExecuteScalar()); } 

现在采取以下外键关系：

我的问题：如何查询“主要/唯一密钥基表”和“主要/唯一密钥列”方面的关系？ 我无法在INFORMATION_SCHEMA视图中看到这些引用。

谢谢J

Answer 1

这是我追求的SQL！

 SELECT FK_Table = FK.TABLE_NAME, FK_Column = CU.COLUMN_NAME, PK_Table = PK.TABLE_NAME, PK_Column = PT.COLUMN_NAME, Constraint_Name = C.CONSTRAINT_NAME FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS C INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS FK ON C.CONSTRAINT_NAME = FK.CONSTRAINT_NAME INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS PK ON C.UNIQUE_CONSTRAINT_NAME = PK.CONSTRAINT_NAME INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE CU ON C.CONSTRAINT_NAME = CU.CONSTRAINT_NAME INNER JOIN ( SELECT i1.TABLE_NAME, i2.COLUMN_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS i1 INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE i2 ON i1.CONSTRAINT_NAME = i2.CONSTRAINT_NAME WHERE i1.CONSTRAINT_TYPE = 'PRIMARY KEY' ) PT ON PT.TABLE_NAME = PK.TABLE_NAME 

Answer 2

如果引用的表（外键正在查看的表）具有唯一键，则Jaimie的答案无法正确返回所有外键，因为它使用UNIQUE_CONSTRAINT_NAME列。 我建议：

 SELECT FK = fk.name, FKTable = QUOTENAME(OBJECT_SCHEMA_NAME(fkcol.[object_id])) + '.' + QUOTENAME(OBJECT_NAME(fkcol.[object_id])), FKCol = fkcol.name, ' references => ', PKTable = QUOTENAME(OBJECT_SCHEMA_NAME(pkcol.[object_id])) + '.' + QUOTENAME(OBJECT_NAME(pkcol.[object_id])), PKCol = pkcol.name FROM sys.foreign_keys AS fk INNER JOIN sys.foreign_key_columns AS fkc ON fk.[object_id] = fkc.constraint_object_id INNER JOIN sys.columns AS fkcol ON fkc.parent_object_id = fkcol.[object_id] AND fkc.parent_column_id = fkcol.column_id INNER JOIN sys.columns AS pkcol ON fkc.referenced_object_id = pkcol.[object_id] AND fkc.referenced_column_id = pkcol.column_id ORDER BY fkc.constraint_column_id; 

资料来源： http ： //sqlblog.com/blogs/aaron_bertrand/archive/2011/11/03/the-case-against-information-schema-views.aspx