sql - 我如何知道 CONSTRAINT_NAME 是主键还是外键？

Question

在 SQL Server 2005 上使用此 SQL

SELECT CONSTRAINT_NAME
FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE 
WHERE TABLE_NAME = @TableName
  AND COLUMN_NAME=@ColumnName

我得到主键和外键。

如何才能只获取外键？ 如何查看约束是主键还是外键？

谢谢

Answer 1

找到了一个更优雅的解决方案 here

下面添加的代码是为了完整性，但所有功劳都归功于 Pinal Dave

SELECT f.name AS ForeignKey,
   OBJECT_NAME(f.parent_object_id) AS TableName,
   COL_NAME(fc.parent_object_id, 
   fc.parent_column_id) AS ColumnName,
   OBJECT_NAME (f.referenced_object_id) AS ReferenceTableName,
   COL_NAME(fc.referenced_object_id, 
   fc.referenced_column_id) AS ReferenceColumnName
FROM sys.foreign_keys AS f
LEFT JOIN sys.foreign_key_columns AS fc
   ON f.OBJECT_ID = fc.constraint_object_id

如果您只想要主键...

SELECT i.name AS IndexName,
        OBJECT_NAME(ic.OBJECT_ID) AS TableName,
        COL_NAME(ic.OBJECT_ID,ic.column_id) AS ColumnName
FROM sys.indexes AS i
        INNER JOIN sys.index_columns AS ic
        ON i.OBJECT_ID = ic.OBJECT_ID 
    AND i.index_id = ic.index_id
WHERE i.is_primary_key = 1

将此添加为附加答案，因为它与我之前的答案相去甚远:)