数据库表反向生成(一) MyBatis-generator与IDEA的集成
在Dao层，通过数据库表反向生成，可以节省我们很多的精力，把更多的精力投入复杂的业务中。
数据库表反向生成，指的是通过数据库如mysql中的库表schema生成dao层读写表的基础代码，包括model(entity)和dao(mapper)。
在本文中我先介绍java中mybatis-generator的反向生成。我们在下一篇文章中会介绍django中ORM的反向生成。
mybatis-generator的反向生成有两种方式
1）源码打包生成mybatis-generator.jar，通过执行jar来生成代码，然后把代码拷贝到工程
2）直接跟编辑器集成，例如IDEA。
我们只说明第二种方式。
1、在IDEA中创建一个maven工程
2、在maven工程的pom文件中添加mybatis-generator-maven-plugin插件
<build> <plugins> <plugin> <groupId>org.mybatis.generator</groupId> <artifactId>mybatis-generator-maven-plugin</artifactId> <version>1.3.2</version> <configuration> <verbose>true</verbose> <overwrite>true</overwrite> </configuration> </plugin> </plugins> </build>
3、在src/main/resources目录下创建两个配置文件，generatorConfig.xml和generator.properties
generatorConfig.xml文件
内容请看注释，<table>中配置的是你要扫描的表。
<?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> <!--导入属性配置 --> <properties resource="generator.properties"></properties> <!--指定特定数据库的jdbc驱动jar包的位置 --> <classPathEntry location="${jdbc.driverLocation}"/> <context id="default" targetRuntime="MyBatis3"> <!-- optional，旨在创建class时，对注释进行控制 --> <commentGenerator> <property name="suppressDate" value="true" /> </commentGenerator> <!--jdbc的数据库连接 --> <jdbcConnection driverClass="${jdbc.driverClass}" connectionURL="${jdbc.connectionURL}" userId="${jdbc.userId}" password="${jdbc.password}"> </jdbcConnection> <!-- 非必需，类型处理器，在数据库类型和java类型之间的转换控制--> <javaTypeResolver > <property name="forceBigDecimals" value="false" /> </javaTypeResolver> <!-- Model模型生成器,用来生成含有主键key的类，记录类 以及查询Example类 targetPackage 指定生成的model生成所在的包名 targetProject 指定在该项目下所在的路径 --> <javaModelGenerator targetPackage="com.xiaoju.dqa.jazz.dao.model" targetProject="src/main/java"> <!-- 是否对model添加 构造函数 --> <property name="constructorBased" value="true"/> <!-- 是否允许子包，即targetPackage.schemaName.tableName --> <property name="enableSubPackages" value="false"/> <!-- 建立的Model对象是否 不可改变 即生成的Model对象不会有 setter方法，只有构造方法 --> <property name="immutable" value="true"/> <!-- 是否对类CHAR类型的列的数据进行trim操作 --> <property name="trimStrings" value="true"/> </javaModelGenerator> <!--Mapper映射文件生成所在的目录 为每一个数据库的表生成对应的SqlMap文件 --> <sqlMapGenerator targetPackage="mybatis-mapper" targetProject="src/main/resources"> <property name="enableSubPackages" value="false"/> </sqlMapGenerator> <!-- 客户端代码，生成易于使用的针对Model对象和XML配置文件 的代码 type="ANNOTATEDMAPPER",生成Java Model 和基于注解的Mapper对象 type="MIXEDMAPPER",生成基于注解的Java Model 和相应的Mapper对象 type="XMLMAPPER",生成SQLMap XML文件和独立的Mapper接口 --> <javaClientGenerator targetPackage="com.xiaoju.dqa.jazz.dao.mapper" targetProject="src/main/java" type="MIXEDMAPPER"> <property name="enableSubPackages" value=""/> <!-- 定义Maper.java 源代码中的ByExample() 方法的可视性，可选的值有： public; private; protected; default 注意：如果 targetRuntime="MyBatis3",此参数被忽略 --> <property name="exampleMethodVisibility" value=""/> <!-- 方法名计数器 Important note: this property is ignored if the target runtime is MyBatis3. --> <property name="methodNameCalculator" value=""/> <!-- 为生成的接口添加父接口 --> <property name="rootInterface" value=""/> </javaClientGenerator> <table tableName="hiveTable" domainObjectName="HiveTable" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"> </table> <table tableName="hiveLocation" domainObjectName="HiveLocation" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"> </table> </context> </generatorConfiguration>
generator.properties文件
这个主要配置的是你的驱动程序和数据库链接，mybatis将去配置的数据库中扫描要生成的表。
jdbc.driverLocation=/Users/didi/.m2/repository/mysql/mysql-connector-java/5.1.40/mysql-connector-java-5.1.40.jar jdbc.driverClass=com.mysql.jdbc.Driver jdbc.connectionURL=jdbc:mysql://localhost:3306/jazz?useUnicode=true&characterEncoding=utf-8 jdbc.userId=root jdbc.password=123456
4、在IDEA中添加Run选项，使用mybatis-generator-maven-plugin
配置如下
1）Name写generator会在run菜单生成一个名叫generator的选项；
2）CommandLine写要执行的命令，mybatis-generator:generate -e
3）working directory写你pom所在的工程，我这里是区分模块开发的，所以在dao模块下。
5、run -> generator执行
这样就会生成对应的代码了
我两张表的建表语句如下：
CREATE TABLE `hiveTable` ( `id` int(100) NOT NULL AUTO_INCREMENT COMMENT '库表唯一Id', `dbName` VARCHAR(100) COMMENT '库名', `tableName` VARCHAR(100) COMMENT '表名', `location` VARCHAR(500) COMMENT '路径', `createTime` DATETIME COMMENT '创建时间', `updateTime` DATETIME COMMENT '更新时间', PRIMARY KEY (`id`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8; CREATE TABLE `hiveLocation` ( `id` int(100) NOT NULL AUTO_INCREMENT COMMENT '路径唯一Id', `location` VARCHAR(500) COMMENT '路径', `size` INT(10) COMMENT '大小', `createTime` DATETIME COMMENT '创建时间', `updateTime` DATETIME COMMENT '更新时间', PRIMARY KEY (`id`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8;
生成的代码如图
我们展示一些生成的代码：
HiveTable.java
package com.xiaoju.dqa.jazz.dao.model; import java.util.Date; public class HiveTable { /** * This field was generated by MyBatis Generator. * This field corresponds to the database column hiveTable.id * * @mbggenerated */ private Integer id; /** * This field was generated by MyBatis Generator. * This field corresponds to the database column hiveTable.dbName * * @mbggenerated */ private String dbname; /** * This field was generated by MyBatis Generator. * This field corresponds to the database column hiveTable.tableName * * @mbggenerated */ private String tablename; /** * This field was generated by MyBatis Generator. * This field corresponds to the database column hiveTable.location * * @mbggenerated */ private String location; /** * This field was generated by MyBatis Generator. * This field corresponds to the database column hiveTable.createTime * * @mbggenerated */ private Date createtime; /** * This field was generated by MyBatis Generator. * This field corresponds to the database column hiveTable.updateTime * * @mbggenerated */ private Date updatetime; /** * This method was generated by MyBatis Generator. * This method corresponds to the database table hiveTable * * @mbggenerated */ public HiveTable(Integer id, String dbname, String tablename, String location, Date createtime, Date updatetime) { this.id = id; this.dbname = dbname; this.tablename = tablename; this.location = location; this.createtime = createtime; this.updatetime = updatetime; } /** * This method was generated by MyBatis Generator. * This method returns the value of the database column hiveTable.id * * @return the value of hiveTable.id * * @mbggenerated */ public Integer getId() { return id; } /** * This method was generated by MyBatis Generator. * This method returns the value of the database column hiveTable.dbName * * @return the value of hiveTable.dbName * * @mbggenerated */ public String getDbname() { return dbname; } /** * This method was generated by MyBatis Generator. * This method returns the value of the database column hiveTable.tableName * * @return the value of hiveTable.tableName * * @mbggenerated */ public String getTablename() { return tablename; } /** * This method was generated by MyBatis Generator. * This method returns the value of the database column hiveTable.location * * @return the value of hiveTable.location * * @mbggenerated */ public String getLocation() { return location; } /** * This method was generated by MyBatis Generator. * This method returns the value of the database column hiveTable.createTime * * @return the value of hiveTable.createTime * * @mbggenerated */ public Date getCreatetime() { return createtime; } /** * This method was generated by MyBatis Generator. * This method returns the value of the database column hiveTable.updateTime * * @return the value of hiveTable.updateTime * * @mbggenerated */ public Date getUpdatetime() { return updatetime; } }
HiveTableMapper.java
package com.xiaoju.dqa.jazz.dao.mapper; import com.xiaoju.dqa.jazz.dao.model.HiveTable; import org.apache.ibatis.annotations.*; @Mapper public interface HiveTableMapper { /** * This method was generated by MyBatis Generator. * This method corresponds to the database table hiveTable * * @mbggenerated */ @Delete({ "delete from hiveTable", "where id = #{id,jdbcType=INTEGER}" }) int deleteByPrimaryKey(Integer id); /** * This method was generated by MyBatis Generator. * This method corresponds to the database table hiveTable * * @mbggenerated */ @Insert({ "insert into hiveTable (id, dbName, ", "tableName, location, ", "createTime, updateTime)", "values (#{id,jdbcType=INTEGER}, #{dbname,jdbcType=VARCHAR}, ", "#{tablename,jdbcType=VARCHAR}, #{location,jdbcType=VARCHAR}, ", "#{createtime,jdbcType=TIMESTAMP}, #{updatetime,jdbcType=TIMESTAMP})" }) int insert(HiveTable record); /** * This method was generated by MyBatis Generator. * This method corresponds to the database table hiveTable * * @mbggenerated */ int insertSelective(HiveTable record); /** * This method was generated by MyBatis Generator. * This method corresponds to the database table hiveTable * * @mbggenerated */ @Select({ "select", "id, dbName, tableName, location, createTime, updateTime", "from hiveTable", "where id = #{id,jdbcType=INTEGER}" }) @ResultMap("BaseResultMap") HiveTable selectByPrimaryKey(Integer id); /** * This method was generated by MyBatis Generator. * This method corresponds to the database table hiveTable * * @mbggenerated */ int updateByPrimaryKeySelective(HiveTable record); /** * This method was generated by MyBatis Generator. * This method corresponds to the database table hiveTable * * @mbggenerated */ @Update({ "update hiveTable", "set dbName = #{dbname,jdbcType=VARCHAR},", "tableName = #{tablename,jdbcType=VARCHAR},", "location = #{location,jdbcType=VARCHAR},", "createTime = #{createtime,jdbcType=TIMESTAMP},", "updateTime = #{updatetime,jdbcType=TIMESTAMP}", "where id = #{id,jdbcType=INTEGER}" }) int updateByPrimaryKey(HiveTable record); }
HiveTableMapper.xml
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" > <mapper namespace="com.xiaoju.dqa.jazz.dao.mapper.HiveTableMapper" > <resultMap id="BaseResultMap" type="com.xiaoju.dqa.jazz.dao.model.HiveTable" > <!-- WARNING - @mbggenerated This element is automatically generated by MyBatis Generator, do not modify. --> <constructor > <idArg column="id" jdbcType="INTEGER" javaType="java.lang.Integer" /> <arg column="dbName" jdbcType="VARCHAR" javaType="java.lang.String" /> <arg column="tableName" jdbcType="VARCHAR" javaType="java.lang.String" /> <arg column="location" jdbcType="VARCHAR" javaType="java.lang.String" /> <arg column="createTime" jdbcType="TIMESTAMP" javaType="java.util.Date" /> <arg column="updateTime" jdbcType="TIMESTAMP" javaType="java.util.Date" /> </constructor> </resultMap> <sql id="Base_Column_List" > <!-- WARNING - @mbggenerated This element is automatically generated by MyBatis Generator, do not modify. --> id, dbName, tableName, location, createTime, updateTime </sql> <insert id="insertSelective" parameterType="com.xiaoju.dqa.jazz.dao.model.HiveTable" > <!-- WARNING - @mbggenerated This element is automatically generated by MyBatis Generator, do not modify. --> insert into hiveTable <trim prefix="(" suffix=")" suffixOverrides="," > <if test="id != null" > id, </if> <if test="dbname != null" > dbName, </if> <if test="tablename != null" > tableName, </if> <if test="location != null" > location, </if> <if test="createtime != null" > createTime, </if> <if test="updatetime != null" > updateTime, </if> </trim> <trim prefix="values (" suffix=")" suffixOverrides="," > <if test="id != null" > #{id,jdbcType=INTEGER}, </if> <if test="dbname != null" > #{dbname,jdbcType=VARCHAR}, </if> <if test="tablename != null" > #{tablename,jdbcType=VARCHAR}, </if> <if test="location != null" > #{location,jdbcType=VARCHAR}, </if> <if test="createtime != null" > #{createtime,jdbcType=TIMESTAMP}, </if> <if test="updatetime != null" > #{updatetime,jdbcType=TIMESTAMP}, </if> </trim> </insert> <update id="updateByPrimaryKeySelective" parameterType="com.xiaoju.dqa.jazz.dao.model.HiveTable" > <!-- WARNING - @mbggenerated This element is automatically generated by MyBatis Generator, do not modify. --> update hiveTable <set > <if test="dbname != null" > dbName = #{dbname,jdbcType=VARCHAR}, </if> <if test="tablename != null" > tableName = #{tablename,jdbcType=VARCHAR}, </if> <if test="location != null" > location = #{location,jdbcType=VARCHAR}, </if> <if test="createtime != null" > createTime = #{createtime,jdbcType=TIMESTAMP}, </if> <if test="updatetime != null" > updateTime = #{updatetime,jdbcType=TIMESTAMP}, </if> </set> where id = #{id,jdbcType=INTEGER} </update> </mapper>
想让xml文件生效，你可以在创建数据源的时候加入xml文件的路径
例如其中的bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mybatis-mapper/*.xml"));
package com.xiaoju.dqa.jazz.dao.configuration; import org.apache.ibatis.session.SqlSessionFactory; import org.mybatis.spring.SqlSessionFactoryBean; import org.mybatis.spring.SqlSessionTemplate; import org.mybatis.spring.annotation.MapperScan; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder; import org.springframework.boot.context.properties.ConfigurationProperties; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.context.annotation.Primary; import org.springframework.core.io.support.PathMatchingResourcePatternResolver; import org.springframework.jdbc.datasource.DataSourceTransactionManager; import javax.sql.DataSource; @Configuration @MapperScan(basePackages = "com.xiaoju.dqa.jazz.dao.mapper", sqlSessionTemplateRef = "jazzSqlSessionTemplate") public class JazzDataSource { @Bean(name = "jazzData") @ConfigurationProperties(prefix = "spring.datasource.jazz") @Primary public DataSource jazzData() { return DataSourceBuilder.create().build(); } @Bean(name = "jazzSqlSessionFactory") @Primary public SqlSessionFactory jazzSqlSessionFactory(@Qualifier("jazzData") DataSource dataSource) throws Exception { SqlSessionFactoryBean bean = new SqlSessionFactoryBean(); bean.setDataSource(dataSource); bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mybatis-mapper/*.xml")); return bean.getObject(); } @Bean(name = "jazzTransactionManager") @Primary public DataSourceTransactionManager jazzTransactionManager(@Qualifier("jazzData") DataSource dataSource) { return new DataSourceTransactionManager(dataSource); } @Bean(name = "jazzSqlSessionTemplate") @Primary public SqlSessionTemplate jazzSqlSessionTemplate(@Qualifier("jazzSqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception { return new SqlSessionTemplate(sqlSessionFactory); } }
