zoukankan      html  css  js  c++  java
  • Mysql学习笔记(附一)

    关于外键约束关系下修改或者删除表的方法:

    http://wenku.baidu.com/link?url=RRaI160kvsdf7ibMLqxN815RvStSyenz_-ig1ONfpRfpfFpqtbGQIL4w3IhAw3XySR7Jfxn4Pncl68bIm3qQ_ZZkpJj_HoBt6tFVLa_IHsu

    mysql中key 、primary key 、unique key 与index区别:

    http://zccst.iteye.com/blog/1697043

    CREATE TABLE products(
    	id INT NOT NULL AUTO_INCREMENT,
    	cid INT NOT NULL DEFAULT '0',
    	name VARCHAR(60) NOT NULL DEFAULT '',
    	price DOUBLE(7,2) NOT NULL DEFAULT '0.00',
    	num INT NOT NULL DEFAULT '0',
    	decn TEXT,
    	ptime INT NOT NULL DEFAULT '0',
    	PRIMARY KEY(id),
    	KEY pname(name,price)
    );
    解析:KEY pname(name,price)	//括号里面有多个,表示创建多列索引,意思是创建名为pname的关于name和price的索引。
    
    CREATE TABLE cats(
    	id INT NOT NULL AUTO_INCREMENT,
    	pid INT NOT NULL DEFAULT '0',
    	name VARCHAR(60) NOT NULL DEFAULT '',
    	desn TEXT,
    	PRIMARY KEY(id),
    	INDEX name(name,pid)
    );
    
    INSERT INTO
    cats(pid,name,desn)
    values(0,'soft','this is soft'),
    (1,'java','this is java'),
    (1,'php'),
    (1,'c++'),
    (2,'j2se'),
    (2,'j2ee'),
    (2,'j2me'),
    (3,'php');
    
    INSERT INTO 
    products(cid,name,price,num,desn,ptime)
    values(1,'javajava','134.5','10','good','123423'),
    (1,'javaone','245.5','24','very good','5345345'),
    (2,'javasd','445.5','24','very good','5345245'),
    (2,'javsdf','455.5','24','very good','534345'),
    (3,'asdf','456.5','24','very good','53445'),
    (3,'javasadftwo','415.5','24','very good','54545'),
    (4,'javatsdwo','452.5','24','very good','55434'),
    (4,'jadfvatwo','415.5','24','very good','534545'),
    (4,'jasdfvatwo','145.5','24','very good','534545'),
    (4,'javsdfatwo','1245.5','24','very good','534445'),
    (5,'javgfdatwo','12245.5','24','very good','535445'),
    (5,'javatwo','1245.5','24','very good','55345'),
    (5,'javatghwo','1545.5','24','very good','53355'),
    (6,'javatfgwo','2845.5','24','very good','534445'),
    (6,'javafgtwo','845.5','24','very good','53425'),
    (7,'javatghwo','8545.5','24','very good','34345'),
    (7,'javatjkwo','5645.5','24','very good','5342345'),
    (7,'javatweto','2745.5','24','very good','534545'),
    (7,'javatrtwo','8245.5','24','very good','534545'),
    (7,'javatwrto','2445.5','24','very good','5345345'),
    (8,'javatwweo','1645.5','24','very good','534545'),
    (8,'javawetweo','1345.5','24','very good','5342345'),
    (8,'javwatwwo','1845.5','24','very good','53456345'),
    (8,'javawetwo','1565.5','24','very good','53345'),
    (2,'javatwcvo','13745.5','24','very good','5342545'),
    (1,'javatdfwo','17345.5','24','very good','534475'),
    (1,'javatwco','3445.5','24','very good','534345');
    

      

  • 相关阅读:
    ecshop 浏览历史样式的修改
    onmouseover 执行 ToolTip 控件
    e​c​s​h​o​p​模​板​ l​b​i​文​件
    JS中 document.getElementById 对象
    JS CSS 网页 简单 右侧 悬浮
    css 简单 返回顶部 代码及注释说明
    php截取等长UFT8中英文混合字串
    Smarty中模板eq相等 ne、neq不相等, gt大于, lt小于
    iOS UI-集合视图(UICollectionView)
    iOS UI-表格控制器(UITableView)-基本使用
  • 原文地址:https://www.cnblogs.com/laohan1221/p/5802458.html
Copyright © 2011-2022 走看看