java编程学习常见函数之流程函数

流程函数

 

 

相关案例

案例1 : 查询员工的工资信息,如果工资> 1000,则显示”你该努力了”,1000~1999,显示”还可以”,2000~2999 则显示不错,否则显示”你很牛”;

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SELECT EMPNO,ENAME,SAL ,(CASE WHEN SAL<1000 THEN “你该努力了” WHEN (SAL >=1000 AND SAL <2000) THEN “还可以” WHEN (SAL >=2000 AND SAL<3000) THEN “不错“ ELSE “你很牛” END ) “评价“FROM EMP;

 

SELECT EMPNO,ENAME,SAL ,(CASE WHEN SAL<1000 THEN “你该努力了” WHEN (SAL >=1000 AND SAL <2000) THEN “还可以” WHEN (SAL >=2000 AND SAL<3000) THEN “不错“ ELSE “你很牛” END ) “评价“FROM EMP;

 

SELECT EMPNO,ENAME,SAL ,(CASE WHEN SAL<1000 THEN “你该努力了” WHEN (SAL >=1000 AND SAL <2000) THEN “还可以” WHEN (SAL >=2000 AND SAL<3000) THEN “不错“ ELSE “你很牛” END ) “评价“FROM EMP;

 

SELECT EMPNO,ENAME,SAL ,(CASE WHEN SAL<1000 THEN “你该努力了” WHEN (SAL >=1000 AND SAL <2000) THEN “还可以” WHEN (SAL >=2000 AND SAL<3000) THEN “不错“ ELSE “你很牛” END ) “评价“FROM EMP;

 

SELECT EMPNO,ENAME,SAL ,(CASE WHEN SAL<1000 THEN “你该努力了” WHEN (SAL >=1000 AND SAL <2000) THEN “还可以” WHEN (SAL >=2000 AND SAL<3000) THEN “不错“ ELSE “你很牛” END ) “评价“FROM EMP;

 

SELECT EMPNO,ENAME,SAL ,(CASE WHEN SAL<1000 THEN “你该努力了” WHEN (SAL >=1000 AND SAL <2000) THEN “还可以” WHEN (SAL >=2000 AND SAL<3000) THEN “不错“ ELSE “你很牛” END ) “评价“FROM EMP;

 

SELECT EMPNO,ENAME,SAL ,(CASE WHEN SAL<1000 THEN “你该努力了” WHEN (SAL >=1000 AND SAL <2000) THEN “还可以” WHEN (SAL >=2000 AND SAL<3000) THEN “不错“ ELSE “你很牛” END ) “评价“FROM EMP;

案例2: 根据员工的职位给员工涨工资,如果是SALESMAN则工资涨10% ; 如果是 MANAGER,则工资涨20%；如果职位是ANALYST则工资涨40% ;其他职位工资不变

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SELECT EMPNO,ENAME,JOB ,SAL “原工资” , (CASE JOB WHEN ‘SALESMAN’ THEN SAL*1.1 WHEN ‘MANAGER’ THEN SAL*1.2 WHEN ‘ANALYST’ THEN SAL*1.4 ELSE SAL END ) NEWSALFROM EMP;

 

SELECT EMPNO,ENAME,JOB ,SAL “原工资” , (CASE JOB WHEN ‘SALESMAN’ THEN SAL*1.1 WHEN ‘MANAGER’ THEN SAL*1.2 WHEN ‘ANALYST’ THEN SAL*1.4 ELSE SAL END ) NEWSALFROM EMP;

 

SELECT EMPNO,ENAME,JOB ,SAL “原工资” , (CASE JOB WHEN ‘SALESMAN’ THEN SAL*1.1 WHEN ‘MANAGER’ THEN SAL*1.2 WHEN ‘ANALYST’ THEN SAL*1.4 ELSE SAL END ) NEWSALFROM EMP;

 

SELECT EMPNO,ENAME,JOB ,SAL “原工资” , (CASE JOB WHEN ‘SALESMAN’ THEN SAL*1.1 WHEN ‘MANAGER’ THEN SAL*1.2 WHEN ‘ANALYST’ THEN SAL*1.4 ELSE SAL END ) NEWSALFROM EMP;

 

SELECT EMPNO,ENAME,JOB ,SAL “原工资” , (CASE JOB WHEN ‘SALESMAN’ THEN SAL*1.1 WHEN ‘MANAGER’ THEN SAL*1.2 WHEN ‘ANALYST’ THEN SAL*1.4 ELSE SAL END ) NEWSALFROM EMP;

 

SELECT EMPNO,ENAME,JOB ,SAL “原工资” , (CASE JOB WHEN ‘SALESMAN’ THEN SAL*1.1 WHEN ‘MANAGER’ THEN SAL*1.2 WHEN ‘ANALYST’ THEN SAL*1.4 ELSE SAL END ) NEWSALFROM EMP;

 

SELECT EMPNO,ENAME,JOB ,SAL “原工资” , (CASE JOB WHEN ‘SALESMAN’ THEN SAL*1.1 WHEN ‘MANAGER’ THEN SAL*1.2 WHEN ‘ANALYST’ THEN SAL*1.4 ELSE SAL END ) NEWSALFROM EMP;

案例3: 查询所有部门编号是20的所有员工的年收入,并且按照年收入进行排序

SELECT EMPNO,ENAME,JOB ,SAL ,COMM, (SAL+IFNULL(COMM,0))*12 “年收入” ,DEPTNOFROM EMPWHERE DEPTNO = 20ORDER BY 年收入 DESC

 

SELECT EMPNO,ENAME,JOB ,SAL ,COMM, (SAL+IFNULL(COMM,0))*12 “年收入” ,DEPTNOFROM EMPWHERE DEPTNO = 20ORDER BY 年收入 DESC

 

SELECT EMPNO,ENAME,JOB ,SAL ,COMM, (SAL+IFNULL(COMM,0))*12 “年收入” ,DEPTNOFROM EMPWHERE DEPTNO = 20ORDER BY 年收入 DESC

 

SELECT EMPNO,ENAME,JOB ,SAL ,COMM, (SAL+IFNULL(COMM,0))*12 “年收入” ,DEPTNOFROM EMPWHERE DEPTNO = 20ORDER BY 年收入 DESC

案例4: 查询7369员工的工资,如果工资 < 1000,则返回”你该努力了” 否则返回 ”还可以”

SELECT EMPNO,ENAME,SAL , IF(SAL <1000 ,”你该努力了”,”还可以”) 工资评价FROM EMPWHERE EMPNO =7369;

 

SELECT EMPNO,ENAME,SAL , IF(SAL <1000 ,”你该努力了”,”还可以”) 工资评价FROM EMPWHERE EMPNO =7369;

 

SELECT EMPNO,ENAME,SAL , IF(SAL <1000 ,”你该努力了”,”还可以”) 工资评价FROM EMPWHERE EMPNO =7369;

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