mysql查询语句

<span class="pl-c"><span class="pl-c">-- 查询姓"杨"名字两个字的学生姓名和性别(模糊)
<span class="pl-k">select stuname, stusex <span class="pl-k">from tb_student <span class="pl-k">where stuname <span class="pl-k">like <span class="pl-s"><span class="pl-pds">‘杨_<span class="pl-pds">‘;
<span class="pl-c"><span class="pl-c">-- 查询姓"杨"名字三个字的学生姓名和性别(模糊)
<span class="pl-k">select stuname, stusex <span class="pl-k">from tb_student <span class="pl-k">where stuname <span class="pl-k">like <span class="pl-s"><span class="pl-pds">‘杨__<span class="pl-pds">‘;<br><br></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>

<span class="pl-c"><span class="pl-c">-- 查询没有录入家庭住址的学生姓名(空值)
<span class="pl-k">select stuname <span class="pl-k">from tb_student <span class="pl-k">where stuaddr is <span class="pl-k">null;</span></span></span></span></span></span><br><br>

<span class="pl-c"><span class="pl-c">-- 查询课程编号为1111的课程的平均成绩(筛选和聚合函数)
<span class="pl-k">select <span class="pl-c1">avg(score) <span class="pl-k">from tb_record <span class="pl-k">where cid<span class="pl-k">=<span class="pl-c1">1111;<br><br></span></span></span></span></span></span></span></span>

<span class="pl-c"><span class="pl-c">-- 查询每个学生的学号和平均成绩(分组和聚合函数)
<span class="pl-k">select sid <span class="pl-k">as 学号, <span class="pl-c1">avg(score) <span class="pl-k">as 平均分 <span class="pl-k">from tb_record <span class="pl-k">group by sid;</span></span></span></span></span></span></span></span>

<span class="pl-c"><span class="pl-c"><span class="pl-k"><span class="pl-c1"><span class="pl-k"><span class="pl-k"><span class="pl-k"><span class="pl-c1"> </span></span></span></span></span></span></span></span>

<span class="pl-c"><span class="pl-c"><span class="pl-k"><span class="pl-k"><span class="pl-k"><span class="pl-k"><span class="pl-s"><span class="pl-pds"><span class="pl-pds"><span class="pl-c"><span class="pl-c"><span class="pl-k"><span class="pl-k"><span class="pl-k"><span class="pl-k"><span class="pl-s"><span class="pl-pds"><span class="pl-pds"> </span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>

mysql查询语句

标签：bsp   ase   模糊   uname   姓名   group   select   条件   end