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参考表:student
多字段查询
mysql> select id,name,birth from student;
所有字段查询
mysql> select * from student;
where指定查询
mysql> select * from student where id=901;mysql> select * from student where id>=904;mysql> select name from student where department='计算机系';
in指定集合查询
mysql> select * from student where birth in(1988,1990);mysql> select * from student where id in(903,906);
not in非范围查询
mysql> select * from student where birth not in(1990,1998);
between and指定范围查询
mysql> select * from student where birth between 1986 and 1988;
not between and不在指定范围的查询
mysql> select * from student where id not between 904 and 906;
like字符串匹配查询
mysql> select * from student where name like '_三';mysql> select * from student where name like '张三';mysql> select * from student where name like '张%';
not like不匹配查询
mysql> select * from student where name not like '张%';
空值查询
mysql> select * from student where address is null;
and多条件查询
mysql> select * from student where name like '张%' and birth>1985;mysql> select * from student where name like '张%' and birth>1985 and id like '%3';
or多条件查询
mysql> select * from student where id=905 or birth=1988;mysql> select * from student where id=905 or birth=1988 or sex='女';
distinct查询结果不重复
mysql> select distinct sex from student;mysql> select distinct department from student;
order by查询结果排序
mysql> select * from student order by birth;mysql> select * from student order by birth asc;mysql> select * from student order by birth desc;
group by分组查询
mysql> select sex,group_concat(name) from student group by sex;mysql> select sex,count(name) from student group by sex;
limit限制查询结果数量
mysql> select * from student limit 2;mysql> select * from student limit 1,3;
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本篇文章给大家带来了关于mysql的相关知识,其中主要介绍了关于架构原理的相关内容,MySQL Server架构自顶向下大致可以分网络连接层、服务层、存储引擎层和系统文件层,下面一起来看一下,希望对大家有帮助。

mysql的msi与zip版本的区别:1、zip包含的安装程序是一种主动安装,而msi包含的是被installer所用的安装文件以提交请求的方式安装;2、zip是一种数据压缩和文档存储的文件格式,msi是微软格式的安装包。

方法:1、利用right函数,语法为“update 表名 set 指定字段 = right(指定字段, length(指定字段)-1)...”;2、利用substring函数,语法为“select substring(指定字段,2)..”。

在mysql中,可以利用char()和REPLACE()函数来替换换行符;REPLACE()函数可以用新字符串替换列中的换行符,而换行符可使用“char(13)”来表示,语法为“replace(字段名,char(13),'新字符串') ”。

转换方法:1、利用cast函数,语法“select * from 表名 order by cast(字段名 as SIGNED)”;2、利用“select * from 表名 order by CONVERT(字段名,SIGNED)”语句。

本篇文章给大家带来了关于mysql的相关知识,其中主要介绍了关于MySQL复制技术的相关问题,包括了异步复制、半同步复制等等内容,下面一起来看一下,希望对大家有帮助。

在mysql中,可以利用REGEXP运算符判断数据是否是数字类型,语法为“String REGEXP '[^0-9.]'”;该运算符是正则表达式的缩写,若数据字符中含有数字时,返回的结果是true,反之返回的结果是false。

本篇文章给大家带来了关于mysql的相关知识,其中主要介绍了mysql高级篇的一些问题,包括了索引是什么、索引底层实现等等问题,下面一起来看一下,希望对大家有帮助。


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