比使用 INFORMATION_SCHEMA.TABLE_CONSTRAINTS 更好的方法

Question

我得到了以下查询，它运行良好，并给出了我想要的结果。然而，返回结果需要 3 秒，我发现这太慢了。

有人知道更好的方法吗？

SELECT 
    @PrimaryKey = ccu.Column_Name 
FROM 
    INFORMATION_SCHEMA.TABLE_CONSTRAINTS tc
INNER JOIN INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE ccu on 
    tc.CONSTRAINT_NAME = ccu.Constraint_name
WHERE 
    tc.CONSTRAINT_TYPE = 'Primary Key' and 
    tc.Table_Name  = @TableName 
    --tc.Table_Schema = 'LookUp'

Answer 1

我很惊讶您的查询需要这么长时间，但您可以通过 SQL Server 目录视图获得相同的信息：

SELECT c.name
FROM sys.indexes AS i
JOIN sys.index_columns AS ic ON ic.object_id = i.object_id AND ic.index_id = i.index_id
JOIN sys.columns AS c ON c.object_id = ic.object_id AND c.column_id = ic.column_id
WHERE
    i.is_primary_key = 1
    AND i.object_id = OBJECT_ID(N'dbo.YourTable', 'U');