T-SQL 在不使用游标的情况下查询实例中的每个数据库

Question

使用 SQL Server 2012。

使用为每个数据库存储的系统视图，我想保留整个实例中所有索引的索引行为摘要。下面的代码收集了一些统计数据并将它们放在一个表中以供以后使用。问题是，我不得不使用游标来遍历实例中的数据库。任何人都可以提出一个更好的方法来做到这一点而不必使用光标？

USE Master
GO

-- If the procedure already exists then update it. 
IF OBJECT_ID('sp_index_stats') IS NOT NULL 
    DROP PROCEDURE sp_index_stats
GO

CREATE PROCEDURE sp_index_stats AS
    DECLARE     @dbname     NVARCHAR(128) 
    DECLARE     @finalSQL   NVARCHAR(1024)

    -- Results of the query are put into a table in Demo_DB. 
    -- So empty it now for the new results. 

    TRUNCATE TABLE Demo_DB.dbo.index_stats

    -- Use a cursor to get a list of all the tables in the instance. 
    DECLARE database_cursor CURSOR LOCAL FOR
        SELECT  name
        FROM    Master.dbo.sysdatabases
        WHERE   name NOT IN ('master', 'model', 'msdb', 'tempdb')

    OPEN database_cursor

    FETCH NEXT FROM database_cursor INTO @dbname

    WHILE @@FETCH_STATUS = 0
    BEGIN
        -- Each database will contain the same structue, so I need
        -- to create a standard query just changing the database name.
        SET @finalSQL = 'INSERT INTO Demo_DB.dbo.index_stats '

        -- Sort out the select statement.
        SET @finalSQL = @finalSQL + 'SELECT sdb.name, st.name, si.name, si.type_desc, '
        SET @finalSQL = @finalSQL + 'si.is_primary_key, si.fill_factor, '
        SET @finalSQL = @finalSQL + 'sd.user_scans, sd.last_user_scan, '
        SET @finalSQL = @finalSQL + 'sd.user_updates, sd.last_user_update '

        -- The 'from' and 'joins' need to be adjusted slightly for each databse. 
        SET @finalSQL = @finalSQL + 'FROM ' + @dbname + '.sys.tables st '
        SET @finalSQL = @finalSQL + 'JOIN ' + @dbname + '.sys.indexes si ON (si.object_id = st.object_id) '
        SET @finalSQL = @finalSQL + 'JOIN ' + @dbname + '.sys.dm_db_index_usage_stats sd ON (si.object_id = sd.object_id) '
        SET @finalSQL = @finalSQL + 'JOIN ' + @dbname + '.sys.databases sdb ON (sdb.database_id = sd.database_id) ;'

        -- Ok, let's run that...
        EXEC (@finalSQL) 

        -- Get the next database in the instance..,
        FETCH NEXT FROM database_cursor INTO @dbname
    END
    CLOSE database_cursor
    DEALLOCATE database_cursor
GO

问候，

JC.

Answer 1

串联呢？

类似这样的东西（没有复制整个存储过程，但希望你能明白要点）

DECLARE @SQL VARCHAR(MAX)

SET @SQL = ''

SELECT @SQL = @SQL + 
'INSERT INTO Demo_DB.dbo.index_stats ' +
'SELECT sdb.name, st.name, si.name, si.type_desc, ' +
'si.is_primary_key, si.fill_factor, ' +
'sd.user_scans, sd.last_user_scan, ' +
'sd.user_updates, sd.last_user_update ' +
'FROM ' + name + '.sys.tables st ' +
'JOIN ' + name + '.sys.indexes si ON (si.object_id = st.object_id) ' +
'JOIN ' + name + '.sys.dm_db_index_usage_stats sd ON (si.object_id = sd.object_id) ' +
'JOIN ' + name + '.sys.databases sdb ON (sdb.database_id = sd.database_id) ;'  
FROM    Master.dbo.sysdatabases
WHERE   name NOT IN ('master', 'model', 'msdb', 'tempdb')

SELECT @SQL

（显然此时没有执行任何操作）。