to lsqkeke(可可): if里面的语句基本是一样的,只是变量名不一样,如第一个if里是A1,第二个if里是A2
--用动态SQL语句试试 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
--示例:create table #t(A1 int, A2 int, A3 int, B1 int, B2 int, B3 int, C1 int, C2 int, C3 int) godeclare @i int,@sql varchar(8000)set @i = 1while @i<=3 begin set @sql = 'declare @A' + cast(@i as varchar(100)) + ' int, @B' + cast(@i as varchar(100)) + ' int, @C' + cast(@i as varchar(100)) + ' int ' set @sql = @sql + 'select @A' + cast(@i as varchar(100)) + ' = A' + cast(@i as varchar(100)) + ',@B' + cast(@i as varchar(100)) + ' = B' + cast(@i as varchar(100)) + ',@C' + cast(@i as varchar(100)) + ' = C' + cast(@i as varchar(100)) + ' from #t ' set @sql = @sql + ' if (@A' + cast(@i as varchar(100)) + '=0 and (@B' + cast(@i as varchar(100)) + ' <>0 and @C' + cast(@i as varchar(100)) + ' <>0)) ' set @sql = @sql + ' begin select ' + cast(@i as varchar(100)) + ' as 已处理 end ' select @sql exec (@sql) set @i = @i + 1 end drop table #t go/* --结果 declare @A1 int, @B1 int, @C1 int select @A1 = A1,@B1 = B1,@C1 = C1 from #t if (@A1=0 and (@B1 <>0 and @C1 <>0)) begin select 1 as 已处理 end declare @A2 int, @B2 int, @C2 int select @A2 = A2,@B2 = B2,@C2 = C2 from #t if (@A2=0 and (@B2 <>0 and @C2 <>0)) begin select 2 as 已处理 end declare @A3 int, @B3 int, @C3 int select @A3 = A3,@B3 = B3,@C3 = C3 from #t if (@A3=0 and (@B3 <>0 and @C3 <>0)) begin select 3 as 已处理 end */
if里面的语句基本是一样的,只是变量名不一样,如第一个if里是A1,第二个if里是A2
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
godeclare @i int,@sql varchar(8000)set @i = 1while @i<=3
begin
set @sql = 'declare @A' + cast(@i as varchar(100)) + ' int, @B' + cast(@i as varchar(100)) + ' int, @C' + cast(@i as varchar(100)) + ' int '
set @sql = @sql + 'select @A' + cast(@i as varchar(100)) + ' = A' + cast(@i as varchar(100)) + ',@B' + cast(@i as varchar(100)) + ' = B' + cast(@i as varchar(100)) + ',@C' + cast(@i as varchar(100)) + ' = C' + cast(@i as varchar(100)) + ' from #t '
set @sql = @sql + ' if (@A' + cast(@i as varchar(100)) + '=0 and (@B' + cast(@i as varchar(100)) + ' <>0 and @C' + cast(@i as varchar(100)) + ' <>0)) '
set @sql = @sql + ' begin select ' + cast(@i as varchar(100)) + ' as 已处理 end ' select @sql exec (@sql) set @i = @i + 1
end
drop table #t
go/*
--结果
declare @A1 int, @B1 int, @C1 int select @A1 = A1,@B1 = B1,@C1 = C1 from #t if (@A1=0 and (@B1 <>0 and @C1 <>0)) begin select 1 as 已处理 end
declare @A2 int, @B2 int, @C2 int select @A2 = A2,@B2 = B2,@C2 = C2 from #t if (@A2=0 and (@B2 <>0 and @C2 <>0)) begin select 2 as 已处理 end
declare @A3 int, @B3 int, @C3 int select @A3 = A3,@B3 = B3,@C3 = C3 from #t if (@A3=0 and (@B3 <>0 and @C3 <>0)) begin select 3 as 已处理 end */