如何查找多个列上存在的索引答案

【问题标题】：How to find index exists on multiple columns如何查找多个列上存在的索引
【发布时间】：2018-10-24 05:40:08
【问题描述】：

我有 delta 脚本 SQL 查询，我必须检查是否存在特定索引，如果不存在则创建一个。

例如表结构：

表A Col1 整数 Col2 varchar Col3 varchar Col4 日期时间

查询是：

IF EXISTS (SELECT 1  
            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.object_id =OBJECT_ID('dbo.tableA') 
                     AND COL_NAME(ic.object_id,ic.column_id) = 'Col2' ) 
BEGIN
    PRINT 'Index Exists!'
END
ELSE
BEGIN
              PRINT 'Nonclustered does not Exists!'
              IF NOT EXISTS (SELECT name FROM sys.indexes WHERE name = N'IX_tableA_Col2_Col3') 
              BEGIN
              PRINT 'Creating index on tableA'
              CREATE NONCLUSTERED INDEX [IX_tableA_Col2_Col3] ON [dbo].[tableA]
              (
                  [Col2] ASC,
                  [Col3] ASC
              )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
              END
END

查询能够检查Col2 上是否有索引，但这里我想要实现的是检查Col2 和Col3 上是否创建了索引，如果没有则创建。

我该怎么做？

【问题讨论】：

标签： sql sql-server database indexing

【解决方案1】：

试试这个查询，它将返回索引的index_id，它是在两个指定的列上创建的：

declare @tblName varchar(20) = 'yourTable',
        @col1 varchar(20) = 'col1',
        @col2 varchar(20) = 'col2';

select index_id from (
    select index_id,
           (select name 
            from sys.columns 
            where object_id = ic.object_id and column_id = ic.column_id
              and name in (@col1, @col2)) name
    from sys.index_columns ic
    where object_name(object_id) = @tblName
) a group by index_id
having count(*) = 2

【讨论】：