44 lines
1.1 KiB
SQL
44 lines
1.1 KiB
SQL
USE db2;
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CREATE TABLE stu4(
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sid INT PRIMARY KEY AUTO_INCREMENT,
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sname VARCHAR(1000),
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age INT,
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address VARCHAR(1000),
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FOREIGN KEY(sname)REFERENCES student(createtime));
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INSERT INTO stu1 VALUES(NULL,'张无忌',25,'光明顶'),(NULL,'赵敏',30,'光明顶1'),(NULL,'周芷若',40,'光明顶2');
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#修改张无忌的地址
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UPDATE stu1 SET address='嵩山' WHERE sname='张无忌';
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#修改周芷若的年龄和地址
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UPDATE stu1 SET address='峨眉',age=50 WHERE sname='周芷若';
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#####mysql中的简单查询
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#查询stu表中的所有记录
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SELECT sid,sname,age,address FROM stu1;
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SELECT * FROM stu1;
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#查阅所有sid和sname,别名as
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SELECT sid AS id,sname AS `name` FROM stu1;
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#查询名字是张无忌的
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SELECT * FROM stu1 WHERE sname='张无忌';
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#查询sid大于2，且年龄大于30的
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SELECT * FROM stu1 WHERE sid>=1 AND age>30
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### 创建部门表
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CREATE TABLE dept (
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did INT PRIMARY KEY,
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dname VARCHAR(100)
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)
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### 创建员工表
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CREATE TABLE emp (
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eid INT PRIMARY KEY,
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ename VARCHAR(100),
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age INT,
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edid INT,
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FOREIGN KEY(edid) REFERENCES dept(did)
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)
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