MySQL Study

1.用load data 命令将数据从文本录入数据库：

数据库中pet表字段：

name owner species sex birth death

文本 d:\pet.txt,字段之间用 tab 隔开

whistle gwen         bird f 1998-10-23
whistle gwen1 bird m 1998-10-24 2100-19-25

mysql>
load data local infile 'd:\pet.txt' into table pet;

2.日期计算
mysql> SELECT name, birth, CURDATE(),
    -> (YEAR(CURDATE())-YEAR(birth))
    -> - (RIGHT(CURDATE(),5)<RIGHT(birth,5))
    -> AS age
    -> FROM pet;
YEAR( )、MONTH( ),DAYOFMONTH( )

unsigned zerofill:  0零填充，1表示为0001
CREATE TABLE shop (

    -> article INT(4) UNSIGNED ZEROFILL DEFAULT '0000' NOT NULL,

    -> dealer  CHAR(20)                 DEFAULT ''     NOT NULL,

    -> price   DOUBLE(16,2)             DEFAULT '0.00' NOT NULL,

    -> PRIMARY KEY(article, dealer));

3. show create table pet,查看pet表的建表sql.