Question

我知道我可以使用以下命令索引表中的列：

CREATE UNIQUE INDEX index_name
ON table_name (column_name)

但是，我有一个250个模式的数据库，每个模式有10个表。我如何，对于每个表，检查列是否存在，然后为其创建索引（如果它存在）？

我正在使用SQL Server 2012。

Answer 1

香蕉答案的一个小变化是使用INFORMATION_SCHEMA.COLUMNS直接获取最终的表格列表：

-- Define column to index.
DECLARE @coltoindex VARCHAR(20), @indexoptions VARCHAR(30)
SET @coltoindex = 'Id'
SET @indexoptions = 'UNIQUE'

--USE database_name
--IF OBJECT_ID('tempdb..#tables') IS NOT NULL DROP TABLE #tables
SELECT table_schema, table_name INTO #tables FROM information_schema.columns
    where COLUMN_NAME = @coltoindex

DECLARE @schema VARCHAR(30), @table VARCHAR(20), @sqlCommand varchar(1000)
WHILE (SELECT COUNT(*) FROM #tables) > 0
BEGIN
    SELECT TOP 1 @schema = table_schema, @table = table_name FROM #tables
    SET @sqlCommand = '
            CREATE ' + @indexoptions + ' INDEX 
            idx_'  + @schema + '_' + @table + '_' + @coltoindex + '
            ON ' + @schema + '.' + @table + ' (' + @coltoindex + ')'
    -- print @sqlCommand
    EXEC (@sqlCommand)
    DELETE FROM #tables WHERE table_schema = @schema AND table_name = @table
END

Answer 2

实现目标的简单方法是loop over all tables through information_schema.tables，然后创建索引if the row exists in that table：

-- Define column to index.
DECLARE @coltoindex VARCHAR(20), @indexoptions VARCHAR(30)
SET @coltoindex = 'Id'
SET @indexoptions = 'UNIQUE'

USE database_name
--IF OBJECT_ID('tempdb..#tables') IS NOT NULL DROP TABLE #tables
SELECT table_schema, table_name INTO #tables FROM information_schema.tables
DECLARE @schema VARCHAR(30), @table VARCHAR(20), @sqlCommand varchar(1000)
WHILE (SELECT COUNT(*) FROM #tables) > 0
BEGIN
    SELECT TOP 1 @schema = table_schema, @table = table_name FROM #tables
    SET @sqlCommand = '
        IF EXISTS(SELECT * FROM sys.columns  
        WHERE [name] = N''' + @coltoindex + ''' 
        AND [object_id] = OBJECT_ID(N''' + @schema + '.' + @table + ''')) 
        BEGIN 
            CREATE ' + @indexoptions + ' INDEX 
            idx_'  + @schema + '_' + @table + '_' + @coltoindex + '
            ON ' + @schema + '.' + @table + ' (' + @coltoindex + ')
        END'
    EXEC (@sqlCommand)
    DELETE FROM #tables WHERE table_schema = @schema AND table_name = @table
END

为数据库中的所有表创建索引？

2 个答案: