11、Mybatis之逆向工程
正向工程：先创建Java实体类，由框架负责根据实体类生成数据库表；例如Hibernate是支持正向工程的。
逆向工程：先创建数据库表，由框架负责根据数据库表，反向生成Java实体类、mapper接口和映射文件。
11.2.1、创建新module
创建名为mybatis_mbg的新module，过程参考5.1节
11.2.2、添加打包方式和依赖及插件
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.rain</groupId>
<artifactId>mybatis_mbg</artifactId>
<version>1.0-SNAPSHOT</version>
<!--打包方式-->
<packaging>jar</packaging>
<!--依赖-->
<dependencies>
<!-- Mybatis核心 -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.7</version>
</dependency>
<!-- junit测试 -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<!-- MySQL驱动 -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.49</version>
</dependency>
<!-- log4j日志 -->
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
</dependencies>
<build>
<!-- 构建过程中用到的插件 -->
<plugins>
<!-- 具体插件，逆向工程的操作是以构建过程中插件形式出现的 -->
<plugin>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-maven-plugin</artifactId>
<version>1.3.0</version>
<!-- 插件的依赖 -->
<dependencies>
<!-- 逆向工程的核心依赖 -->
<dependency>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-core</artifactId>
<version>1.3.2</version>
</dependency>
<!-- MySQL驱动 -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.49</version>
</dependency>
</dependencies>
</plugin>
</plugins>
</build>
</project>
注意：文件名必须是generatorConfig.xml
<?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>
<!--
targetRuntime属性: 设置执行生成逆向工程的版本
MyBatis3Simple: 生成基本的CRUD（简洁版）
MyBatis3: 生成带条件的CRUD（进阶版）
-->
<context id="DB2Tables" targetRuntime="MyBatis3Simple">
<!-- 数据库的连接信息 -->
<jdbcConnection driverClass="com.mysql.jdbc.Driver"
connectionURL="jdbc:mysql://localhost:3306/ssm?characterEncoding=utf-8"
userId="root"
password="root">
</jdbcConnection>
<!-- javaBean的生成策略-->
<javaModelGenerator targetPackage="org.rain.mybatis.pojo" targetProject=".\src\main\java">
<property name="enableSubPackages" value="true" />
<property name="trimStrings" value="true" />
</javaModelGenerator>
<!-- SQL映射文件的生成策略 -->
<sqlMapGenerator targetPackage="org.rain.mybatis.mapper" targetProject=".\src\main\resources">
<property name="enableSubPackages" value="true" />
</sqlMapGenerator>
<!-- Mapper接口的生成策略 -->
<javaClientGenerator type="XMLMAPPER" targetPackage="org.rain.mybatis.mapper" targetProject=".\src\main\java">
<property name="enableSubPackages" value="true" />
</javaClientGenerator>
<!-- 逆向分析的表 -->
<!-- tableName设置为*号，可以对应所有表，此时不写domainObjectName -->
<!-- domainObjectName属性指定生成出来的实体类的类名 -->
<table tableName="t_emp" domainObjectName="Emp"/>
<table tableName="t_dept" domainObjectName="Dept"/>
</context>
</generatorConfiguration>
- 找到mybatis-generator插件，并双击执行
11.5.1、总体概览
注意：如图所示，实体类、接口和映射文件都自动生成了
11.5.2、实体类生成内容示例
package org.rain.mybatis.pojo;
public class Dept {
/**
* This field was generated by MyBatis Generator.
* This field corresponds to the database column t_dept.dept_id
*
* @mbggenerated Wed Jul 05 11:25:17 CST 2023
*/
private Integer deptId;
/**
* This field was generated by MyBatis Generator.
* This field corresponds to the database column t_dept.dept_name
*
* @mbggenerated Wed Jul 05 11:25:17 CST 2023
*/
private String deptName;
/**
* This method was generated by MyBatis Generator.
* This method returns the value of the database column t_dept.dept_id
*
* @return the value of t_dept.dept_id
*
* @mbggenerated Wed Jul 05 11:25:17 CST 2023
*/
public Integer getDeptId() {
return deptId;
}
/**
* This method was generated by MyBatis Generator.
* This method sets the value of the database column t_dept.dept_id
*
* @param deptId the value for t_dept.dept_id
*
* @mbggenerated Wed Jul 05 11:25:17 CST 2023
*/
public void setDeptId(Integer deptId) {
this.deptId = deptId;
}
/**
* This method was generated by MyBatis Generator.
* This method returns the value of the database column t_dept.dept_name
*
* @return the value of t_dept.dept_name
*
* @mbggenerated Wed Jul 05 11:25:17 CST 2023
*/
public String getDeptName() {
return deptName;
}
/**
* This method was generated by MyBatis Generator.
* This method sets the value of the database column t_dept.dept_name
*
* @param deptName the value for t_dept.dept_name
*
* @mbggenerated Wed Jul 05 11:25:17 CST 2023
*/
public void setDeptName(String deptName) {
this.deptName = deptName == null ? null : deptName.trim();
}
}11.5.3、mapper接口生成内容示例
package org.rain.mybatis.mapper;
import java.util.List;
import org.rain.mybatis.pojo.Dept;
public interface DeptMapper {
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Wed Jul 05 11:25:17 CST 2023
*/
int deleteByPrimaryKey(Integer deptId);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Wed Jul 05 11:25:17 CST 2023
*/
int insert(Dept record);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Wed Jul 05 11:25:17 CST 2023
*/
Dept selectByPrimaryKey(Integer deptId);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Wed Jul 05 11:25:17 CST 2023
*/
List<Dept> selectAll();
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Wed Jul 05 11:25:17 CST 2023
*/
int updateByPrimaryKey(Dept record);
}11.5.4、映射文件生成内容示例
<?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="org.rain.mybatis.mapper.DeptMapper" >
<resultMap id="BaseResultMap" type="org.rain.mybatis.pojo.Dept" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Wed Jul 05 11:25:17 CST 2023.
-->
<id column="dept_id" property="deptId" jdbcType="INTEGER" />
<result column="dept_name" property="deptName" jdbcType="VARCHAR" />
</resultMap>
<delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Wed Jul 05 11:25:17 CST 2023.
-->
delete from t_dept
where dept_id = #{deptId,jdbcType=INTEGER}
</delete>
<insert id="insert" parameterType="org.rain.mybatis.pojo.Dept" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Wed Jul 05 11:25:17 CST 2023.
-->
insert into t_dept (dept_id, dept_name)
values (#{deptId,jdbcType=INTEGER}, #{deptName,jdbcType=VARCHAR})
</insert>
<update id="updateByPrimaryKey" parameterType="org.rain.mybatis.pojo.Dept" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Wed Jul 05 11:25:17 CST 2023.
-->
update t_dept
set dept_name = #{deptName,jdbcType=VARCHAR}
where dept_id = #{deptId,jdbcType=INTEGER}
</update>
<select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Wed Jul 05 11:25:17 CST 2023.
-->
select dept_id, dept_name
from t_dept
where dept_id = #{deptId,jdbcType=INTEGER}
</select>
<select id="selectAll" resultMap="BaseResultMap" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Wed Jul 05 11:25:17 CST 2023.
-->
select dept_id, dept_name
from t_dept
</select>
</mapper>11.6.1、修改逆向工程配置文件
11.6.2、删除之前简单版生成的内容
++++++++++++++++++++分割线++++++++++++++++++++++
11.6.3、执行mybatis-generator插件
11.6.4、插件执行效果(进阶版)
11.6.4.1、总体概览
注意：进阶版生成的实体类，比简洁版的多了xxxExample
11.6.4.2、实体类生成内容示例
package org.rain.mybatis.pojo;
public class Dept {
/**
* This field was generated by MyBatis Generator.
* This field corresponds to the database column t_dept.dept_id
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
private Integer deptId;
/**
* This field was generated by MyBatis Generator.
* This field corresponds to the database column t_dept.dept_name
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
private String deptName;
/**
* This method was generated by MyBatis Generator.
* This method returns the value of the database column t_dept.dept_id
*
* @return the value of t_dept.dept_id
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
public Integer getDeptId() {
return deptId;
}
/**
* This method was generated by MyBatis Generator.
* This method sets the value of the database column t_dept.dept_id
*
* @param deptId the value for t_dept.dept_id
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
public void setDeptId(Integer deptId) {
this.deptId = deptId;
}
/**
* This method was generated by MyBatis Generator.
* This method returns the value of the database column t_dept.dept_name
*
* @return the value of t_dept.dept_name
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
public String getDeptName() {
return deptName;
}
/**
* This method was generated by MyBatis Generator.
* This method sets the value of the database column t_dept.dept_name
*
* @param deptName the value for t_dept.dept_name
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
public void setDeptName(String deptName) {
this.deptName = deptName == null ? null : deptName.trim();
}
}11.6.4.3、实体类Example生成内容示例
package org.rain.mybatis.pojo;
import java.util.ArrayList;
import java.util.List;
public class DeptExample {
/**
* This field was generated by MyBatis Generator.
* This field corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
protected String orderByClause;
/**
* This field was generated by MyBatis Generator.
* This field corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
protected boolean distinct;
/**
* This field was generated by MyBatis Generator.
* This field corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
protected List<Criteria> oredCriteria;
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
public DeptExample() {
oredCriteria = new ArrayList<Criteria>();
}
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
public void setOrderByClause(String orderByClause) {
this.orderByClause = orderByClause;
}
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
public String getOrderByClause() {
return orderByClause;
}
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
public void setDistinct(boolean distinct) {
this.distinct = distinct;
}
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
public boolean isDistinct() {
return distinct;
}
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
public List<Criteria> getOredCriteria() {
return oredCriteria;
}
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
public void or(Criteria criteria) {
oredCriteria.add(criteria);
}
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
public Criteria or() {
Criteria criteria = createCriteriaInternal();
oredCriteria.add(criteria);
return criteria;
}
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
public Criteria createCriteria() {
Criteria criteria = createCriteriaInternal();
if (oredCriteria.size() == 0) {
oredCriteria.add(criteria);
}
return criteria;
}
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
protected Criteria createCriteriaInternal() {
Criteria criteria = new Criteria();
return criteria;
}
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
public void clear() {
oredCriteria.clear();
orderByClause = null;
distinct = false;
}
/**
* This class was generated by MyBatis Generator.
* This class corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
protected abstract static class GeneratedCriteria {
protected List<Criterion> criteria;
protected GeneratedCriteria() {
super();
criteria = new ArrayList<Criterion>();
}
public boolean isValid() {
return criteria.size() > 0;
}
public List<Criterion> getAllCriteria() {
return criteria;
}
public List<Criterion> getCriteria() {
return criteria;
}
protected void addCriterion(String condition) {
if (condition == null) {
throw new RuntimeException("Value for condition cannot be null");
}
criteria.add(new Criterion(condition));
}
protected void addCriterion(String condition, Object value, String property) {
if (value == null) {
throw new RuntimeException("Value for " + property + " cannot be null");
}
criteria.add(new Criterion(condition, value));
}
protected void addCriterion(String condition, Object value1, Object value2, String property) {
if (value1 == null || value2 == null) {
throw new RuntimeException("Between values for " + property + " cannot be null");
}
criteria.add(new Criterion(condition, value1, value2));
}
public Criteria andDeptIdIsNull() {
addCriterion("dept_id is null");
return (Criteria) this;
}
public Criteria andDeptIdIsNotNull() {
addCriterion("dept_id is not null");
return (Criteria) this;
}
public Criteria andDeptIdEqualTo(Integer value) {
addCriterion("dept_id =", value, "deptId");
return (Criteria) this;
}
public Criteria andDeptIdNotEqualTo(Integer value) {
addCriterion("dept_id <>", value, "deptId");
return (Criteria) this;
}
public Criteria andDeptIdGreaterThan(Integer value) {
addCriterion("dept_id >", value, "deptId");
return (Criteria) this;
}
public Criteria andDeptIdGreaterThanOrEqualTo(Integer value) {
addCriterion("dept_id >=", value, "deptId");
return (Criteria) this;
}
public Criteria andDeptIdLessThan(Integer value) {
addCriterion("dept_id <", value, "deptId");
return (Criteria) this;
}
public Criteria andDeptIdLessThanOrEqualTo(Integer value) {
addCriterion("dept_id <=", value, "deptId");
return (Criteria) this;
}
public Criteria andDeptIdIn(List<Integer> values) {
addCriterion("dept_id in", values, "deptId");
return (Criteria) this;
}
public Criteria andDeptIdNotIn(List<Integer> values) {
addCriterion("dept_id not in", values, "deptId");
return (Criteria) this;
}
public Criteria andDeptIdBetween(Integer value1, Integer value2) {
addCriterion("dept_id between", value1, value2, "deptId");
return (Criteria) this;
}
public Criteria andDeptIdNotBetween(Integer value1, Integer value2) {
addCriterion("dept_id not between", value1, value2, "deptId");
return (Criteria) this;
}
public Criteria andDeptNameIsNull() {
addCriterion("dept_name is null");
return (Criteria) this;
}
public Criteria andDeptNameIsNotNull() {
addCriterion("dept_name is not null");
return (Criteria) this;
}
public Criteria andDeptNameEqualTo(String value) {
addCriterion("dept_name =", value, "deptName");
return (Criteria) this;
}
public Criteria andDeptNameNotEqualTo(String value) {
addCriterion("dept_name <>", value, "deptName");
return (Criteria) this;
}
public Criteria andDeptNameGreaterThan(String value) {
addCriterion("dept_name >", value, "deptName");
return (Criteria) this;
}
public Criteria andDeptNameGreaterThanOrEqualTo(String value) {
addCriterion("dept_name >=", value, "deptName");
return (Criteria) this;
}
public Criteria andDeptNameLessThan(String value) {
addCriterion("dept_name <", value, "deptName");
return (Criteria) this;
}
public Criteria andDeptNameLessThanOrEqualTo(String value) {
addCriterion("dept_name <=", value, "deptName");
return (Criteria) this;
}
public Criteria andDeptNameLike(String value) {
addCriterion("dept_name like", value, "deptName");
return (Criteria) this;
}
public Criteria andDeptNameNotLike(String value) {
addCriterion("dept_name not like", value, "deptName");
return (Criteria) this;
}
public Criteria andDeptNameIn(List<String> values) {
addCriterion("dept_name in", values, "deptName");
return (Criteria) this;
}
public Criteria andDeptNameNotIn(List<String> values) {
addCriterion("dept_name not in", values, "deptName");
return (Criteria) this;
}
public Criteria andDeptNameBetween(String value1, String value2) {
addCriterion("dept_name between", value1, value2, "deptName");
return (Criteria) this;
}
public Criteria andDeptNameNotBetween(String value1, String value2) {
addCriterion("dept_name not between", value1, value2, "deptName");
return (Criteria) this;
}
}
/**
* This class was generated by MyBatis Generator.
* This class corresponds to the database table t_dept
*
* @mbggenerated do_not_delete_during_merge Thu Jul 06 11:01:56 CST 2023
*/
public static class Criteria extends GeneratedCriteria {
protected Criteria() {
super();
}
}
/**
* This class was generated by MyBatis Generator.
* This class corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
public static class Criterion {
private String condition;
private Object value;
private Object secondValue;
private boolean noValue;
private boolean singleValue;
private boolean betweenValue;
private boolean listValue;
private String typeHandler;
public String getCondition() {
return condition;
}
public Object getValue() {
return value;
}
public Object getSecondValue() {
return secondValue;
}
public boolean isNoValue() {
return noValue;
}
public boolean isSingleValue() {
return singleValue;
}
public boolean isBetweenValue() {
return betweenValue;
}
public boolean isListValue() {
return listValue;
}
public String getTypeHandler() {
return typeHandler;
}
protected Criterion(String condition) {
super();
this.condition = condition;
this.typeHandler = null;
this.noValue = true;
}
protected Criterion(String condition, Object value, String typeHandler) {
super();
this.condition = condition;
this.value = value;
this.typeHandler = typeHandler;
if (value instanceof List<?>) {
this.listValue = true;
} else {
this.singleValue = true;
}
}
protected Criterion(String condition, Object value) {
this(condition, value, null);
}
protected Criterion(String condition, Object value, Object secondValue, String typeHandler) {
super();
this.condition = condition;
this.value = value;
this.secondValue = secondValue;
this.typeHandler = typeHandler;
this.betweenValue = true;
}
protected Criterion(String condition, Object value, Object secondValue) {
this(condition, value, secondValue, null);
}
}
}11.6.4.4、mapper接口生成内容示例
package org.rain.mybatis.mapper;
import java.util.List;
import org.apache.ibatis.annotations.Param;
import org.rain.mybatis.pojo.Dept;
import org.rain.mybatis.pojo.DeptExample;
public interface DeptMapper {
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
int countByExample(DeptExample example);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
int deleteByExample(DeptExample example);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
int deleteByPrimaryKey(Integer deptId);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
int insert(Dept record);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
int insertSelective(Dept record);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
List<Dept> selectByExample(DeptExample example);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
Dept selectByPrimaryKey(Integer deptId);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
int updateByExampleSelective(@Param("record") Dept record, @Param("example") DeptExample example);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
int updateByExample(@Param("record") Dept record, @Param("example") DeptExample example);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
int updateByPrimaryKeySelective(Dept record);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table t_dept
*
* @mbggenerated Thu Jul 06 11:01:56 CST 2023
*/
int updateByPrimaryKey(Dept record);
}11.6.4.5、映射文件生成内容示例
<?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="org.rain.mybatis.mapper.DeptMapper" >
<resultMap id="BaseResultMap" type="org.rain.mybatis.pojo.Dept" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Jul 06 11:01:56 CST 2023.
-->
<id column="dept_id" property="deptId" jdbcType="INTEGER" />
<result column="dept_name" property="deptName" jdbcType="VARCHAR" />
</resultMap>
<sql id="Example_Where_Clause" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Jul 06 11:01:56 CST 2023.
-->
<where >
<foreach collection="oredCriteria" item="criteria" separator="or" >
<if test="criteria.valid" >
<trim prefix="(" suffix=")" prefixOverrides="and" >
<foreach collection="criteria.criteria" item="criterion" >
<choose >
<when test="criterion.noValue" >
and ${criterion.condition}
</when>
<when test="criterion.singleValue" >
and ${criterion.condition} #{criterion.value}
</when>
<when test="criterion.betweenValue" >
and ${criterion.condition} #{criterion.value} and #{criterion.secondValue}
</when>
<when test="criterion.listValue" >
and ${criterion.condition}
<foreach collection="criterion.value" item="listItem" open="(" close=")" separator="," >
#{listItem}
</foreach>
</when>
</choose>
</foreach>
</trim>
</if>
</foreach>
</where>
</sql>
<sql id="Update_By_Example_Where_Clause" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Jul 06 11:01:56 CST 2023.
-->
<where >
<foreach collection="example.oredCriteria" item="criteria" separator="or" >
<if test="criteria.valid" >
<trim prefix="(" suffix=")" prefixOverrides="and" >
<foreach collection="criteria.criteria" item="criterion" >
<choose >
<when test="criterion.noValue" >
and ${criterion.condition}
</when>
<when test="criterion.singleValue" >
and ${criterion.condition} #{criterion.value}
</when>
<when test="criterion.betweenValue" >
and ${criterion.condition} #{criterion.value} and #{criterion.secondValue}
</when>
<when test="criterion.listValue" >
and ${criterion.condition}
<foreach collection="criterion.value" item="listItem" open="(" close=")" separator="," >
#{listItem}
</foreach>
</when>
</choose>
</foreach>
</trim>
</if>
</foreach>
</where>
</sql>
<sql id="Base_Column_List" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Jul 06 11:01:56 CST 2023.
-->
dept_id, dept_name
</sql>
<select id="selectByExample" resultMap="BaseResultMap" parameterType="org.rain.mybatis.pojo.DeptExample" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Jul 06 11:01:56 CST 2023.
-->
select
<if test="distinct" >
distinct
</if>
<include refid="Base_Column_List" />
from t_dept
<if test="_parameter != null" >
<include refid="Example_Where_Clause" />
</if>
<if test="orderByClause != null" >
order by ${orderByClause}
</if>
</select>
<select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Jul 06 11:01:56 CST 2023.
-->
select
<include refid="Base_Column_List" />
from t_dept
where dept_id = #{deptId,jdbcType=INTEGER}
</select>
<delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Jul 06 11:01:56 CST 2023.
-->
delete from t_dept
where dept_id = #{deptId,jdbcType=INTEGER}
</delete>
<delete id="deleteByExample" parameterType="org.rain.mybatis.pojo.DeptExample" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Jul 06 11:01:56 CST 2023.
-->
delete from t_dept
<if test="_parameter != null" >
<include refid="Example_Where_Clause" />
</if>
</delete>
<insert id="insert" parameterType="org.rain.mybatis.pojo.Dept" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Jul 06 11:01:56 CST 2023.
-->
insert into t_dept (dept_id, dept_name)
values (#{deptId,jdbcType=INTEGER}, #{deptName,jdbcType=VARCHAR})
</insert>
<insert id="insertSelective" parameterType="org.rain.mybatis.pojo.Dept" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Jul 06 11:01:56 CST 2023.
-->
insert into t_dept
<trim prefix="(" suffix=")" suffixOverrides="," >
<if test="deptId != null" >
dept_id,
</if>
<if test="deptName != null" >
dept_name,
</if>
</trim>
<trim prefix="values (" suffix=")" suffixOverrides="," >
<if test="deptId != null" >
#{deptId,jdbcType=INTEGER},
</if>
<if test="deptName != null" >
#{deptName,jdbcType=VARCHAR},
</if>
</trim>
</insert>
<select id="countByExample" parameterType="org.rain.mybatis.pojo.DeptExample" resultType="java.lang.Integer" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Jul 06 11:01:56 CST 2023.
-->
select count(*) from t_dept
<if test="_parameter != null" >
<include refid="Example_Where_Clause" />
</if>
</select>
<update id="updateByExampleSelective" parameterType="map" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Jul 06 11:01:56 CST 2023.
-->
update t_dept
<set >
<if test="record.deptId != null" >
dept_id = #{record.deptId,jdbcType=INTEGER},
</if>
<if test="record.deptName != null" >
dept_name = #{record.deptName,jdbcType=VARCHAR},
</if>
</set>
<if test="_parameter != null" >
<include refid="Update_By_Example_Where_Clause" />
</if>
</update>
<update id="updateByExample" parameterType="map" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Jul 06 11:01:56 CST 2023.
-->
update t_dept
set dept_id = #{record.deptId,jdbcType=INTEGER},
dept_name = #{record.deptName,jdbcType=VARCHAR}
<if test="_parameter != null" >
<include refid="Update_By_Example_Where_Clause" />
</if>
</update>
<update id="updateByPrimaryKeySelective" parameterType="org.rain.mybatis.pojo.Dept" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Jul 06 11:01:56 CST 2023.
-->
update t_dept
<set >
<if test="deptName != null" >
dept_name = #{deptName,jdbcType=VARCHAR},
</if>
</set>
where dept_id = #{deptId,jdbcType=INTEGER}
</update>
<update id="updateByPrimaryKey" parameterType="org.rain.mybatis.pojo.Dept" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Jul 06 11:01:56 CST 2023.
-->
update t_dept
set dept_name = #{deptName,jdbcType=VARCHAR}
where dept_id = #{deptId,jdbcType=INTEGER}
</update>
</mapper>11.7.1、引入相关配置文件
11.7.1.1、jdbc.properties
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/ssm?characterEncoding=utf-8
jdbc.username=root
jdbc.password=root11.7.1.2、mybatis-config.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<properties resource="jdbc.properties"/>
<settings>
<!--将下划线映射为驼峰-->
<setting name="mapUnderscoreToCamelCase" value="true"/>
<!--开启延迟加载-->
<!--<setting name="lazyLoadingEnabled" value="true"/>-->
<!--开启二级缓存-->
<setting name="cacheEnabled" value="true"/>
</settings>
<typeAliases>
<package name="org.rain.mybatis.pojo"/>
</typeAliases>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="${jdbc.driver}"/>
<property name="url" value="${jdbc.url}"/>
<property name="username" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
</dataSource>
</environment>
</environments>
<mappers>
<package name="org.rain.mybatis.mapper"/>
</mappers>
</configuration>11.7.1.3、log4j.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
<appender name="STDOUT" class="org.apache.log4j.ConsoleAppender">
<param name="Encoding" value="UTF-8" />
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%-5p %d{MM-dd HH:mm:ss,SSS} %m (%F:%L) \n" />
</layout>
</appender>
<logger name="java.sql">
<level value="debug" />
</logger>
<logger name="org.apache.ibatis">
<level value="info" />
</logger>
<root>
<level value="debug" />
<appender-ref ref="STDOUT" />
</root>
</log4j:configuration>11.7.2、创建获取SqlSession工具类
package org.rain.mybatis.utils;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import java.io.IOException;
import java.io.InputStream;
public class SqlSessionUtils {
public static SqlSession getSqlSession(){
SqlSession sqlSession = null;
try {
//读取MyBatis核心配置文件的输入流
InputStream is = Resources.getResourceAsStream("mybatis-config.xml");
//创建SqlSessionFactoryBuilder对象
SqlSessionFactoryBuilder sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();
//通过核心配置文件所对应的字节输入流创建工厂类SqlSessionFactory，用于生产SqlSession对象
SqlSessionFactory sqlSessionFactory = sqlSessionFactoryBuilder.build(is);
//创建自动提交事务的SqlSession对象
sqlSession = sqlSessionFactory.openSession(true);
} catch (IOException e) {
e.printStackTrace();
}
return sqlSession;
}
}11.7.3、创建测试类
11.7.4、根据主键查询一条数据
注意：生成的实体类没有tostring方法，因此需要手动在实体类添加tostring方法才有相关输出
@Test
public void testMbg(){
SqlSession sqlSession = SqlSessionUtils.getSqlSession();
EmpMapper empMapper = sqlSession.getMapper(EmpMapper.class);
//根据主键查询一条数据
Emp emp = empMapper.selectByPrimaryKey(1);
System.out.println(emp);
}11.7.5、查询所有数据
注意：无条件查询（即xxxExample为null）就是查询所有
@Test
public void testMbg(){
SqlSession sqlSession = SqlSessionUtils.getSqlSession();
EmpMapper empMapper = sqlSession.getMapper(EmpMapper.class);
//查询所有数据
List<Emp> emps = empMapper.selectByExample(null);
for (Emp emp : emps) {
System.out.println(emp);
}
}11.7.6、多条件查询(QBC风格)
@Test
public void testMbg(){
SqlSession sqlSession = SqlSessionUtils.getSqlSession();
EmpMapper empMapper = sqlSession.getMapper(EmpMapper.class);
//多条件查询，QBC（query by condition）风格
EmpExample empExample = new EmpExample();
empExample.createCriteria().andEmpNameEqualTo("小红").andEmpIdBetween(8,10);
empExample.or().andAgeEqualTo(20);
List<Emp> emps = empMapper.selectByExample(empExample);
for (Emp emp : emps) {
System.out.println(emp);
}
}11.7.7、普通修改
++++++++++++++++++++++++分割线++++++++++++++++++++++++
++++++++++++++++++++++++分割线++++++++++++++++++++++++
注意：如图所示，普通修改会将显式设置为null或未设置的字段都修改为null
@Test
public void testMbg(){
SqlSession sqlSession = SqlSessionUtils.getSqlSession();
EmpMapper empMapper = sqlSession.getMapper(EmpMapper.class);
Emp emp = new Emp();
emp.setEmpId(4);
emp.setEmpName("小军");
emp.setAge(null);
emp.setGender("女");
empMapper.updateByPrimaryKey(emp);
}11.7.8、选择性修改
++++++++++++++++++++++++分割线++++++++++++++++++++++++
++++++++++++++++++++++++分割线++++++++++++++++++++++++
注意：如图所示，选择性修改不会将显式设置为null或未设置的字段修改为null
@Test
public void testMbg(){
SqlSession sqlSession = SqlSessionUtils.getSqlSession();
EmpMapper empMapper = sqlSession.getMapper(EmpMapper.class);
Emp emp = new Emp();
emp.setEmpId(3);
emp.setEmpName("小军");
emp.setAge(null);
emp.setGender("女");
empMapper.updateByPrimaryKeySelective(emp);
}手机扫一扫
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