about 数据库
mysql
常见建表语句
1.默认时间戳
CREATE TABLE `a_data_for_knowledge` (
`id` INT ( 11 ) NOT NULL AUTO_INCREMENT,
`price` DECIMAL ( 13, 2 ) NOT NULL,
`question` VARCHAR ( 500 ) NOT NULL,
`answer` text NOT NULL,
`date` TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
PRIMARY KEY ( `id` )
) ENGINE = INNODB AUTO_INCREMENT = 0 DEFAULT CHARSET = utf8mb4;