显示数据表信息和结构: SHOW CREATE TABLE tb1;
显示数据表列结构: SHOW COLUMNS FROM tb1;
显示数据表全部记录： SELECT * FROM tb1
插入记录: INSERT tb_name [(col_name, ...)] VALUES(val,..)
设置主键和排序： CREATE TABLE tb3(id SMALLINT UNSIGNED AUTO_INCREMENT KEY,username VARCHAR(30));
主键约束唯一约束： PRIMARY KEY, UNIQUE KEY
设置默认值：
CREATE TABLE tb6(
id SMALLINT UNSIGNED AUTO_INCREMENT KEY,
username VARCHAR(20) NOT NULL UNIQUE KEY,
sex ENUM('1','2','3') DEFAULT '3'
);
- 外键约束：
CREATE TABLE province(
id SMALLINT UNSIGNED PRIMARY KEY AUTO_INCREMENT,
pname VARCHAR(20) NOT NULL
);
CREATE TABLE users(
id SMALLINT UNSIGNED PRIMARY KEY AUTO_INCREMENT,
username VARCHAR(10) NOT NULL,
pid SMALLINT UNSIGNED,
FOREIGN KEY (pid) REFERENCES province(id)
);
SHOW INDEXES FROM province\G;
SHOW INDEXES FROM users\G;
