将变量传递给DROP INDEX语句

无论如何，总之，我想测试某个列是否有索引，如果是，请删除索引。我想知道我是否可以通过将索引名称传递给DROP INDEX语句。

首先，FYI表名是'Account'，列名是'ID'。

要测试索引存在我用下面的（不要以为我是任何类型的天才，我从这里的SELECT语句）： http://social.msdn.microsoft.com/Forums/sqlserver/en-US/e183be6c-1177-4f81-b130-aeeeff7638fe/how-do-you-check-if-an-index-exists-for-sql-table-column

IF EXISTS 
(SELECT 
    sysindex.name AS IndexName 
FROM 
    sys.indexes AS SysIndex 
    INNER JOIN sys.index_columns AS SysIndexCol ON SysIndex.object_id = SysIndexCol.object_id AND SysIndex.index_id = SysIndexCol.index_id 
    INNER JOIN sys.columns AS SysCols ON SysIndexCol.column_id = SysCols.column_id AND SysIndexCol.object_id = SysCols.object_id 
WHERE 
    type <> 0 
    AND SysIndex.object_id in (Select systbl.object_id from sys.tables as systbl 
    WHERE SysTbl.name = 'Account') 
    AND SysCols.name = 'ID') 

DROP INDEX dbo.Account.Account$ID; 
GO

在DROP INDEX上面的语句我已经硬编码了索引名称（'Account $ ID'） - 如果你自己运行SELECT语句，它会显示名称，但它也很容易通过SSMS识别。但是，而不是硬编码的索引名称，我想能够以某种方式传递索引名称（就像我说的，由SELECT语句显示）到DROP INDEX语句。我想这将通过声明一个变量并以某种方式将其设置为查询结果来完成，但我不知道该怎么做。可以做到吗？

来源

2013-09-25 blackvan

你可以使用类似的东西。注意表名被设置为一个变量。

DECLARE @index_name NVARCHAR(MAX), @table_name NVARCHAR(MAX) 

SET @table_name = 'Account' -- your table name 

SELECT TOP 1 
    @index_name = sysindex.name 
FROM 
    sys.indexes AS SysIndex 
    INNER JOIN sys.index_columns AS SysIndexCol ON SysIndex.object_id = SysIndexCol.object_id AND SysIndex.index_id = SysIndexCol.index_id 
    INNER JOIN sys.columns AS SysCols ON SysIndexCol.column_id = SysCols.column_id AND SysIndexCol.object_id = SysCols.object_id 
WHERE 
    type <> 0 
    AND SysIndex.object_id in (Select systbl.object_id from sys.tables as systbl 
    WHERE SysTbl.name = @table_name) 
    AND SysCols.name = 'id' 

DECLARE @sql NVARCHAR(MAX) = N'DROP INDEX dbo.' + @table_name + '.' + @index_name 

IF @index_name IS NOT NULL 
    exec sp_executesql @sql

EDIT

我添加TOP 1以上，因为它可能返回多于一个索引的查询。

来源

2013-09-25 04:02:04 Szymon

尝试这一个 -

DECLARE @index_name SYSNAME 
    , @table_name SYSNAME = 'dbo.Account' 
    , @column_name SYSNAME = 'ID' 

SELECT @index_name = i.name 
FROM sys.indexes i 
JOIN sys.index_columns ic ON i.[object_id] = ic.[object_id] 
    AND i.index_id = ic.index_id 
WHERE i.[type] > 0 
    AND i.[object_id] = OBJECT_ID(@table_name) 
    AND COL_NAME(i.[object_id], ic.column_id) = @column_name 

DECLARE @SQL NVARCHAR(MAX) = 'DROP INDEX ' + @table_name + '.' + @index_name 
EXEC sp_executesql @SQL

来源

2013-09-25 05:29:59 Devart

将变量传递给DROP INDEX语句

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