1.數據庫的創建和刪除
登錄mysql:123456爲密碼
mysql>mysql -u root -p123456
數據庫的創建:
mysql>create database test;
數據庫的刪除:
mysql>drop database test;
2.數據表的操作
- 創建數據表:
CREATE TABLE IF NOT EXISTS `data_schema`( `ID` INT UNSIGNED AUTO_INCREMENT, `NAME` VARCHAR(100) NOT NULL, `AGE` INT(10) NOT NULL, `SEX` VARCHAR(20), PRIMARY KEY ( `ID` ) )ENGINE=InnoDB DEFAULT CHARSET=utf8;
其中,(1)AUTO_INCREMENT定義列爲自增的屬性,一般用於主鍵,數值會自動加1。(2)PRIMARY KEY關鍵字用於定義列爲主鍵。 您可以使用多列來定義主鍵,列間以逗號分隔。(3)ENGINE 設置存儲引擎,CHARSET 設置編碼。
-
刪除數據表:DROP TABLE table_name 如:DROP TABLE data_shema
-
增(插入數據):insert into data_schema(NAME,AGE,SEX)values('wangkai','15','man')
-
刪(刪除數據):
delete from data_schema where ID=3;
delete from data_schema where SEX='MAN' and NAME=' wangkai';
-
改:update data_schema set NAME='張三',AGE='70',SEX='man' where ID=3;
-
查:
select * from data_schema//查詢表裏所有的數據
select NAME from data_schema//查詢表中某個字段的所有數據
select NAME from data_schema where NAME like '%kai%' //模糊查找
select * from data_schema age ='22'
-
LIKE的使用:(模糊匹配)
查詢以 kai 字段開頭的信息: SELECT * FROM data_schema WHERE NAME LIKE 'kai%';
查詢包含 kai 字段的信息: SELECT * FROM data_schema WHERE NAME LIKE '%kai%';
查詢以 kai字段結尾的信息 : SELECT * FROM data_schema WHERE NAME LIKE '%kai';
-
mysql排序:
SELECT * from data_schema ORDER BY NAME ASC(升序)
SELECT * from data_schema ORDER BY NAME DESC(降序)