常用SQL语句

// 创建表
CREATE TABLE employee(     
    id INT NOT NULL PRIMARY KEY,     
    name VARCHAR(50),     
    city VARCHAR(50) DEFAULT "Hangzhou",     
    salary FLOAT DEFAULT "1000" 
);
// 向表中插入数据
INSERT INTO employee VALUES(1, "Tom", "Beijing", "1100");
INSERT INTO employee (id, name) VALUES(2, "Jack");
// 修改某列的默认值
ALTER TABLE employee ALTER city SET DEFAULT "Beijing";
// 删除某列的默认值
ALTER TABLE employee ALTER city DROP DEFAULT;

常用SQL语句

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