Mysql

MySQL安裝和使用

案例1：MySQL使用練習

• 創建一個數據庫，庫名ovls

  create database ovls default charset utf8;
  

• 在ovls庫中創建一個video表

  id  INT PK  主鍵  
  name VARCHAR (50) 視頻名稱  
  url VARCHAR (100) not  Null 視頻路徑  
  chapter_id  INT 章節id  
  

  use ovls;

  create table video(
  id int primary key autoincrement,
  name varchar(50),
  url varchar(100),
  chapterid int
  ) engine=innodb default charset=utf8;

• 向video表插入以下記錄

  1   Java01   /java/01/1.avi  1
  2   Java02   /java/01/2.avi  1
  3   Java03   /java/01/3.avi  2
  

  insert into video (name,url,chapter_id) values ('Java01','/java/01/1.avi',1);

• 將video表某條記錄刪除

  delete from video where id=5;

• 將video表某條記錄name值更新

  update video set name='Java03' where id=2;

• 查詢video表第2頁記錄，每頁5條

  select * from video limit 5,5;

案例2：構建項目數據庫結構

需求：新建一個studyonline庫，導入studyonline.sql數據庫結構。

• 創建studyonline庫

  create database studyonline default charset=utf8;
  

• 使用studyonline庫

  use studyonline;
  

• 導入studyonline.sql文件(UTF-8編碼文件)

  set names utf8;  
  source xxx/xxx/studyonline.sql;
  

案例3：利用MyBatis-Generator工具

可以根據現有數據庫生成實體類和Mapper接口。

1. 在pom.xml中導入mybatis-generator工具包

   <dependencies>
       <dependency>
         <groupId>org.mybatis.generator</groupId>
         <artifactId>mybatis-generator-core</artifactId>
         <version>1.3.6</version>
       </dependency>
   
       <dependency>
         <groupId>mysql</groupId>
         <artifactId>mysql-connector-java</artifactId>
         <version>5.1.8</version>
       </dependency>
   
   </dependencies>
   

2. 在project下創建一個mbg.xml配置文件,修改定義

   <?xml version="1.0" encoding="UTF-8"?>
   <!DOCTYPE generatorConfiguration
     PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
     "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
   
   <generatorConfiguration>
       <!-- 指定驅動包 -->
     <classPathEntry location="C:\Users\Administrator\.m2\repository\mysql\mysql-connector-Java\5.1.8\mysql-connector-java-5.1.8.jar" />
   
       <!-- 指定連接參數 -->
     <context id="MySQLTables" targetRuntime="MyBatis3">
       <jdbcConnection driverClass="com.mysql.jdbc.Driver"
           connectionURL="jdbc:mysql://localhost:3306/studyonline"
           userId="root"
           password="1234">
       </jdbcConnection>
   
       <!-- 指定Java實體類存放包路徑 -->
       <javaModelGenerator targetPackage="cn.xdl.ovls.entity" targetProject=".\src\main\java">
         <property name="enableSubPackages" value="true" />
         <property name="trimStrings" value="true" />
       </javaModelGenerator>
   
       <!-- 指定SQL定義XML文件存放位置 -->
       <sqlMapGenerator targetPackage="cn.xdl.ovls.sql"  targetProject=".\src\main\java">
         <property name="enableSubPackages" value="true" />
       </sqlMapGenerator>
   
       <!-- 指定Mapper映射器接口存放位置Dao -->
       <!-- type指定爲XMLMAPPER意思是生成SQL的XML文件；
           type指定爲ANNOTATEDMAPPER意思是將SQL生成到Mapper接口中，sqlMapGenerator無效 -->
       <javaClientGenerator type="ANNOTATEDMAPPER" targetPackage="cn.xdl.ovls.dao"  targetProject=".\src\main\java">
         <property name="enableSubPackages" value="true" />
       </javaClientGenerator>
   
       <!-- 指定將哪些表生成 -->
       <table tableName="%" 
           enableCountByExample="false" enableSelectByExample="false"
           enableDeleteByExample="false" enableUpdateByExample="false">
       </table>
   
     </context>
   </generatorConfiguration>
   

3. 定義一個啓動類，加載mbg.xml執行生成工具

   public class MyBatisRunner {
   
       public static void main(String[] args) throws Exception{
           List<String> warnings = new ArrayList<String>();
           boolean overwrite = true;
           File configFile = new File("mbg.xml");
           ConfigurationParser cp = new ConfigurationParser(warnings);
           Configuration config = cp.parseConfiguration(configFile);
           DefaultShellCallback callback = new DefaultShellCallback(overwrite);
           MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings);
           myBatisGenerator.generate(null);
       }
   
   }