cmd mysql -hlocalhost -uroot -p select * from emp where ename like '___' -- 三个横线, - 代表字符,可以查询 三个ename是3个字符数据 select * from emp where job like '___员'; -- job是四个字符且以 员 字结尾 select * from emp where ename like 'm%'; --查询 ename 以 m 开头的记录,% 匹配 0 - n个任何字符…
首先初始化表和数据 create table t_student( Id INT, Name varchar(), Score int, ClassId INT ); insert into t_student values (,,); insert into t_student values (,,); insert into t_student values (,,); insert into t_student values (,,); insert into t_stud…
1.模糊查询 like % 表示多个任意字符 _ 表示任意一个字符 例如:查询黄姓同学 select * from student where name '黄%' select * from student where name '黄_' 2. 范围查询 in 表示在一个非连续的范围内 select id from student where id in (1,2,3) 优先级由高到低的顺序为:小括号,not, 比较运算符 ,逻辑运算符 and 比 or 先运算, 同时出现并希望先算 or ,需…
controller内内容如下 <?php /** * Created by PhpStorm. * User: work * Date: 2018/1/2 * Time: 20:36 */ namespace App\Http\Controllers; use App\Student\Student; use Illuminate\Support\Facades\DB; Route::any('query1','StudentController@query1');查询构造器方法 添加方法…
算术运算符 逻辑运算符 比较运算符 聚合函数 算术运算符(+ - * / ) select score*2 as 成绩翻倍 from class_A update class_A set score=score+20 where score<70 update class_A set score=score-20 where score>70 update class_A set score=score/2 where score>70 逻辑运算符(and/or/between A an…
