Question

目标：

我想知道一个表最近每天更新一次。

是否有一种更有效的方法来查询数据库中每个表的max（insert_stamp），而无需执行以下操作：

select 't1' as table_name, max(insert_stamp) as latest_update
from t1
union all
select 't2' as table_name, max(insert_stamp)
from t2
...

或类似的东西：

use products
go
SELECT  st.name as table_name, ... (column name with insert_stamp)
from sys.tables st
where st.name not like ('staging%')
group by st.name
order by 1

Answer 1

我真的很讨厌这个，但这是我刚刚快速输入的内容。

我讨厌将动态sql用于此类操作，但有时您别无选择
这可能是游标或递归cte
还有，总循环。

但是，这将为您提供所需的东西。

SELECT 
    name
    , ROW_NUMBER() OVER (Order by name asc) as ROWID 
INTO #tmp 
FROM sys.Objects WHERE type='U'

declare @count int, @rowMax int, @date datetime, @sql varchar(max);
set @count = 1
set @rowMax =(SELECT Max(ROWID) FROM #tmp);

CREATE TABLE #dates
    (
        name varchar(255)
        , timestamp datetime
    )

WHILE @count <= @RowMax
    BEGIN
        set @sql = 'SELECT MAX(insert_stamp) FROM '+(SELECT Name FROM #tmp WHERE ROWID=@count)+';'
        exec sp_executesql @sql, N'@x datetime out', @date out
        INSERT INTO #dates SELECT (SELECT Name FROM #tmp WHERE ROWID=@count), @date
        set @count=@count+1
    END

SELECT * FROM #dates

查询以从数据库中获取每个表的最大插入标记

1 个答案: