动态sql语句基本语法
1 :普通SQL语句可以用Exec执行 eg: Select * from tableName
Exec('select * from tableName')
Exec sp_executesql N'select * from tableName' -- 请注意字符串前一定要加N 2:字段名,表名,数据库名之类作为变量时,必须用动态SQL eg:
declare @fname varchar(20)
set @fname = 'FiledName'
Select @fname from tableName -- 错误,不会提示错误,但结果为固定值FiledName,并非所要。
Exec('select ' + @fname + ' from tableName') -- 请注意 加号前后的 单引号的边上加空格 当然将字符串改成变量的形式也可
declare @fname varchar(20)
set @fname = 'FiledName' --设置字段名 declare @s varchar(1000)
set @s = 'select ' + @fname + ' from tableName'
Exec(@s) -- 成功
exec sp_executesql @s -- 此句会报错 declare @s Nvarchar(1000) -- 注意此处改为nvarchar(1000)
set @s = 'select ' + @fname + ' from tableName'
Exec(@s) -- 成功
exec sp_executesql @s -- 此句正确 3. 输出参数
declare @num int,
@sqls nvarchar(4000)
set @sqls='select count(*) from tableName'
exec(@sqls)
--如何将exec执行结果放入变量中? declare @num int,
@sqls nvarchar(4000)
set @sqls='select @a=count(*) from tableName '
exec sp_executesql @sqls,N'@a int output',@num output
select @num
1 :普通SQL语句可以用Exec执行 eg: Select * from tableName
Exec('select * from tableName')
Exec sp_executesql N'select * from tableName' -- 请注意字符串前一定要加N 2:字段名,表名,数据库名之类作为变量时,必须用动态SQL eg:
declare @fname varchar(20)
set @fname = 'FiledName'
Select @fname from tableName -- 错误,不会提示错误,但结果为固定值FiledName,并非所要。
Exec('select ' + @fname + ' from tableName') -- 请注意 加号前后的 单引号的边上加空格 当然将字符串改成变量的形式也可
declare @fname varchar(20)
set @fname = 'FiledName' --设置字段名 declare @s varchar(1000)
set @s = 'select ' + @fname + ' from tableName'
Exec(@s) -- 成功
exec sp_executesql @s -- 此句会报错 declare @s Nvarchar(1000) -- 注意此处改为nvarchar(1000)
set @s = 'select ' + @fname + ' from tableName'
Exec(@s) -- 成功
exec sp_executesql @s -- 此句正确 3. 输出参数
declare @num int,
@sqls nvarchar(4000)
set @sqls='select count(*) from tableName'
exec(@sqls)
--如何将exec执行结果放入变量中? declare @num int,
@sqls nvarchar(4000)
set @sqls='select @a=count(*) from tableName '
exec sp_executesql @sqls,N'@a int output',@num output
select @num
exec('select * FROM A where STCD in ('+@stcdlist+')')
TRY:declare @stcdlist varchar(8000)
set @stcdlist='50100100,50102350,50103100'
set @stcdlist=HQ_SwitchStcdList(@stcdlist)
select * FROM A where ',' + @stcdlist +',' LIKE '%,' + STCD + ',%'
declare @stcdlist varchar(8000)
set @stcdlist='50100100,50102350,50103100'
if charindex(','+'50100100'+',', ','+@stcdlist+',')>0 --50100100-->你的字段
print 'found'
set @stcdlist='50100100,50102350,50103100'
set @stcdlist=HQ_SwitchStcdList(@stcdlist)
select * FROM A where charindex(','+ltrim(STCD)+',',','+@stcdlist+',')>0
set @stcdlist='50100100,50102350,50103100'
set @stcdlist=HQ_SwitchStcdList(@stcdlist)
select * FROM A where charindex(','+ltrim(STCD)+',',','+@stcdlist+',')>0
create table A
(
STCD NVARCHAR(50)
)INSERT INTO A
VALUES('50102350')declare @stcdlist varchar(8000)
set @stcdlist='''50100100'',''50102350'',''50103100'''
PRINT @stcdlist
--set @stcdlist=HQ_SwitchStcdList(@stcdlist)
select * FROM A where ',' + @stcdlist +',' LIKE '%,' + ''''+STCD+'''' + ',%'DROP TABLE A
结果:
50102350
set @stcdlist='50100100,50102350,50103100'
set @stcdlist=dbo.HQ_SwitchStcdList(@stcdlist)
select * FROM st_pptn_r where charindex(','''+ltrim(STCD)+''',',','+@stcdlist+',')>0不过这个语句效率太低了