mysql中查找一个表的某一属性的值的所有和和

您好，是这样的：declare @str varchar(100)set @str='U8中的销售发票、采购发票 关键字' --要搜索的字符串 declare @s varchar(8000)declare tb cursor local forselect s='if exists(select 1 from ['+b.name+'] where ['+a.name+'] like ''%'+@str+'%'') print ''所在的表及字段: ['+b.name+'].['+a.name+']'''from syscolumns a join sysobjects b on a.id=b.idwhere b.xtype='U' and a.status>=0 and a.xusertype in(175,239,231,167)open tbfetch next from tb into @swhile @@fetch_status=0begin exec(@s) fetch next from tb into @sendclose tbdeallocate tb

MySQL InnoDB 表数据页或者二级索引页（简称数据页或者索引页）的合并与分裂对 InnoDB 表整体性能影响很大；数据页的这类 *** 作越多，对 InnoDB 表数据写入的影响越大。

MySQL 提供了一个数据页合并临界值（MERGE_THRESHOLD），在某些场景下，可以人为介入，减少数据页的合并与分裂。

在 InnoDB 表里，每个数据页默认16K 大小，默认 MERGE_THRESHOLD 值为 50，取值范围从 1 到 50，默认值即是最大值。也就是当页面记录数占比小于 50% 时，MySQL 会把这页和相邻的页面进行合并，保证数据页的紧凑，避免太多浪费。

用视图呗..用表得用触发器.或者存储...

create table student_class

(

id int(4) not null auto_increment,

name varchar(20) not null,

class varchar(20) not null,

years int(4) not null,

score double not null,

primary key (id)

)

engine = innodb default charset = utf8

insert into student_class values (null,'张三','高三一班',2012,180.00)

insert into student_class values (null,'张三','高三一班',2013,88.00)

insert into student_class values (null,'张三','高三一班',2014,181.00)

insert into student_class values (null,'李四','高三一班',2012,102.00)

insert into student_class values (null,'李四','高三一班',2013,183.00)

insert into student_class values (null,'李四','高三一班',2014,184.00)

insert into student_class values (null,'王五','高三二班',2012,185.00)

insert into student_class values (null,'王五','高三二班',2013,186.00)

insert into student_class values (null,'王五','高三二班',2014,181.00)

insert into student_class values (null,'赵六','高三二班',2012,183.00)

insert into student_class values (null,'赵六','高三二班',2013,184.00)

insert into student_class values (null,'赵六','高三二班',2014,185.00)

create view student_years as select class,years,sum(score),avg(score) from student_class group by class,years

mysql>select * from student_years

+--------------+-------+------------+------------+

| class| years | sum(score) | avg(score) |

+--------------+-------+------------+------------+

| 高三一班 | 2012 |282 |141 |

| 高三一班 | 2013 |271 | 135.5 |

| 高三一班 | 2014 |365 | 182.5 |

| 高三二班 | 2012 |368 |184 |

| 高三二班 | 2013 |370 |185 |

| 高三二班 | 2014 |366 |183 |

+--------------+-------+------------+------------+

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