mysql在线sql语句测试

辕狗码2731mysql sql语句查询多少列 -
慎世饼15069813285 ______ MySQL使用SQL查询时,可以指定单列,如下:select uid from dusers 也可以指定多列如下:select uid,uname from dusers 也可以指定全部列 select * from dusers 以上只是简单查询,对于连接查询的示例类同,只是型式不太一样.select a.uid,a....

辕狗码2731mysql中的这个sql语句怎么写? -
慎世饼15069813285 ______ select * from (select uid,count(*) as [count] from 表名 group by uid) as t where t.[count]=7

辕狗码2731mysql的sql语句怎么写? -
慎世饼15069813285 ______ 哥,你把这些前面加个聚合函数不就得了,max或者sum都行 然后分下组

辕狗码2731请教一个mysql的sql语句的写法 -
慎世饼15069813285 ______ select concat( replace(substring('＂2014-01-01＂;＂0＂',1,instr('＂2014-01-01＂;＂0＂','1')),'0',&#...

辕狗码2731mysql 数据库 执行语句 -
慎世饼15069813285 ______ 1.利用临时表 select articleid,min(chapterid) chapterid into temp table ttt from 一个表 where chaptertype=1; delete from 一个表 where chaptertype=1 and articleid not in (select articleid from ttt); 2.这个实际上是替换 update 一个表 set chaptername=...

辕狗码2731sql 语句如何在mysql里实现
慎世饼15069813285 ______ SQL codeset @account=(select count(id)from table_1);SELECT CONCAT('account=',@account); 对我有用[0]丢个板砖[0]引用举报管理TOPrucypli(我要冰糖)等 级:

辕狗码2731mysql一个sql语句的编写 -
慎世饼15069813285 ______ select t1.typeid,t1.count1/t2.count2from(select a.typeid,count(*) count1 from 图书表 a,借阅表 b where a.bookId=b.bookId group by a.typeid) t1,(select count(*) count2 from 借阅表) t2

辕狗码2731求一句mysql sql语句 -
慎世饼15069813285 ______ 判断A中是否存在mod字段,不存在则新增. if not exists(select * from syscolumns where id=object_id('A') and name='mod') --不存在 begin ALTER TABLE A ADD mod NVARCHAR(20) --新增mod字段,字符串类型 end else print(' exists ') --提示已经存在

辕狗码2731求循环查询赋值SQL语句!在线等~! -
慎世饼15069813285 ______ ALTER PROCEDURE p_test AS declare @tags varchar(10) declare @ret varchar(50) declare @aid int declare cur_aid cursor for select distinct aid from dedejcw_taglist open cur_aid fetch next from cur_aid into @aid while @@fetch_status = 0 ...