MySql查询

基本数据查询

全表查询

select * from tableName;

查询部分字段

select Field from tableName;

计数1

select count(*) from tableName;

计数2

select count(1) from tableName;

条件过滤

and （并且）

select * from tableName where 条件1 and 条件2;

or（或者）

select * from tableName where 条件1 or 条件2;

in（包含）

select * from tableName where Field in(value1,value2);

between ··· and ···（范围检查）

select * from tableName where Field between a and b;

not （否定结果）

select * from tableName where Field not in(value1,value2);

select * from tableName where Field not between a and b;

%（匹配任意字符）

select * from tableName where Field like "要匹配的字符%";

^（匹配以···开头的字符）

select * from tableName where Field rlike "^要匹配的字符";

$（匹配以···结尾的字符）

select * from tableName where Field rlike "要匹配的字符$";

限制表的查询条数limit

select * from tableName limit N;

对结果信息排序

默认排序

select * from tableName order by Field limit N;

升序排序asc

select * from tableName order by Field asc limit N;

降序排序desc

select * from tableName order by Field desc limit N;

 字符串的排序是按照ASCII码值排序的。

聚合函数

查询总数(count)

总和(sum)

平均(averge)

最大（max）

最小（min）

去重(distinct)

过滤(having)