使用游标建立视图的一个实例（涉及多张表）

Posted 2020-12-01 哈西

declare @x varchar(2000)
declare @y varchar(2000)
declare @str varchar(max)
declare @sql varchar(max)
declare @flag int --标记循环次数
set @flag=1
set @str=‘‘--保存建立视图的语句
DECLARE @table_name varchar(2000)
DECLARE cursor2 CURSOR FOR    --定义游标cursor2
SELECT name FROM  (select name  from sysobjects where xtype=‘U‘  and   name not like ‘%copy%‘ and name not like  ‘[A-Z]%‘ and name not like  ‘[a-z]%‘  ) t -- 共84条记录
OPEN cursor2                  --打开游标
FETCH NEXT FROM cursor2 INTO @table_name
WHILE @@FETCH_STATUS=0        --判断是否成功获取数据
        
        BEGIN

set @sql=‘select   *   from   syscolumns   where   id=object_id(‘‘‘+  @table_name +‘‘‘)   and   name=‘‘is_delete ‘‘‘--单引号需要转义，用两个单引号表示
set @flag=@flag+1
exec(@sql) 
if @@rowcount=1 --@@rowcount返回受上一语句影响的行数，判断是否有1行受影响
begin
 if @flag<82 --多个条件需要加()
begin        
set @x=‘ select name=‘‘‘+@table_name+‘‘‘,  zero=(SELECT count(*) from ‘+ @table_name +‘ where is_delete=0),one=(SELECT count(*) from ‘+ @table_name +‘ where is_delete=1),two=(SELECT count(*) from ‘+ @table_name +‘ where is_delete=2),three=(SELECT count(*) from ‘+ @table_name +‘ where is_delete=3) union ‘
set @str=@str+@x
print @flag
print @str
end

else
begin
print @flag
set @y=‘select name=‘‘‘+@table_name+‘‘‘, zero= (SELECT count(*) from ‘+ @table_name +‘  where is_delete=0),one=(SELECT count(*) from ‘+ @table_name +‘ where is_delete=1),two=(SELECT count(*) from ‘+ @table_name +‘ where is_delete=2),three=(SELECT count(*) from ‘+ @table_name +‘ where is_delete=3) ‘
set @str=‘create view tb as ‘+@str+@y
print @str
exec (@str) 
break
end
end
            FETCH NEXT FROM cursor2 INTO @table_name  
        END
CLOSE cursor2                 --关闭游标
DEALLOCATE cursor2