日期:2014-05-17 浏览次数:20859 次
CREATE TABLE table_yuwen
(
table_id int,
table_chengji int,
table_type varchar(10)
)
INSERT INTO table_yuwen
select 1,70,'语文' union
select 2,80,'语文'
create table table_shuxue
(
table_id int,
table_chengji int,
table_type varchar(10)
)
insert into table_shuxue
select 1,70,'数学' union
select 2,90,'数学'
create table lock_table
(
lock_id int,
lock_table varchar(20), --表名
table_id int --表名id
)
insert into lock_table
select 1,'table_yuwen',1 union
select 2,'table_shuxue',1
/*
要求结果:
lock_id lock_table table_id table_type table_chengji
----------- -------------------- ----------- ---------- -------------
1 table_yuwen 1 语文 70
2 table_shuxue 1 数学 70
(2 行受影响)
*/
drop table table_yuwen
drop table table_shuxue
drop table lock_table
CREATE TABLE table_yuwen
(
table_id int,
table_chengji int,
table_type nvarchar(10)
)
INSERT INTO table_yuwen
select 1,70,N'语文' union
select 2,80,N'语文'
create table table_shuxue
(
table_id int,
table_chengji int,
table_type nvarchar(10)
)
insert into table_shuxue
select 1,70,N'数学' union
select 2,90,N'数学'
create table lock_table
(
lock_id int,
lock_table varchar(20), --表名
table_id int --表名id
)
insert into lock_table
select 1,'table_yuwen',1 union
select 2,'table_shuxue',1
declare @sql nvarchar(max)
select @sql=isnull(@sql,'')+stuff((select ' union all '+('select *,'''+lock_table+''' lock_table from '+lock_table+' where table_id='+ltrim(table_id)) from lock_table
for xml path('')),1,10,'')
select @sql='select lock_id,tt.* from lock_table t,('+@sql+')tt where t.table_id=tt.table_id and tt.lock_table=t.lock_table '
exec(@sql)
/*
lock_id table_id table_chengji table_type lock_table
----------- ----------- ------------- ---------- ------------
1 1 70 语文 table_yuwen
2 1 70 数学 table_shuxue
*/
------解决方案--------------------
DECLARE @row INT,@i INT,@sql VARCHAR(MAX)
SET @i=1
IF OBJECT_ID('tempdb..#t') IS NOT NULL DROP TABLE #t
SELECT DISTINCT id=IDENTITY(INT,1,1),lock_table INTO #t FROM lock_table
SET @row=@@ROWCOUNT
WHILE @i<=@row
BEGIN
SELECT @sql=ISNULL(@sql+CHAR(10)+'UNION ALL'+CHAR(10),'')+'SELECT * FROM lock_table AS a JOIN '+lock_table+
' AS b ON a.table_id=b.table_id AND lock_table='''+lock_table+''''
FROM #t WHERE id=@i
SET @i=@i+1
END
EXEC(@sql)