MyBatis Generator 简介
MyBatis Generator 连接数据库表并生成MyBatis或iBatis文件。这有助于最大限度地减少使用MyBatis时为数据库文件创建简单CRUD操作所需的工作量。
参考文档：http://www.mybatis.org/generator/
下载地址：https://github.com/mybatis/generator/releases
MyBatis Generator 使用
本例环境已安装java环境，且数据库是mysql，表结构如下：
CREATE DATABASE test_mybatis;
USE test_mybatis; -- ----------------------------
-- Table structure for employee
-- ----------------------------
DROP TABLE IF EXISTS `employee`;
CREATE TABLE `employee` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`last_name` varchar(255) DEFAULT NULL,
`gender` char(1) DEFAULT NULL,
`email` varchar(255) DEFAULT NULL,
`dept_id` int(11) DEFAULT NULL COMMENT '部门ID',
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=36 DEFAULT CHARSET=utf8; -- ----------------------------
-- Records of employee
-- ----------------------------
BEGIN;
INSERT INTO `employee` VALUES (1, '大白', '', 'dabai@163.com', 1);
INSERT INTO `employee` VALUES (2, '小明', '', 'xiaoming@163.com', 1);
INSERT INTO `employee` VALUES (3, '小红', '', 'xiaohong@163.com', 1);
COMMIT;
1、使用命令行的方式使用
a、下载mybatis-generator，如下：
、
b、新建配置文件mbg.xml，参考文档：http://www.mybatis.org/generator/
<?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> <classPathEntry
location="/Users/h__d/.m2/repository/mysql/mysql-connector-java/8.0.13/mysql-connector-java-8.0.13.jar" /> <!--
context:生成一组对象的环境
id:必选，上下文id，用于在生成错误时提示
defaultModelType:指定生成对象的样式
1，conditional：类似hierarchical；
2，flat：所有内容（主键，blob）等全部生成在一个对象中；
3，hierarchical：主键生成一个XXKey对象(key class)，Blob等单独生成一个对象，其他简单属性在一个对象中(record class)
targetRuntime:
1，MyBatis3：默认的值，生成基于MyBatis3.x以上版本的内容，包括XXXBySample；
2，MyBatis3Simple：类似MyBatis3，只是不生成XXXBySample；
introspectedColumnImpl：类全限定名，用于扩展MBG
-->
<context id="DB2Tables" targetRuntime="MyBatis3"> <!-- 自动识别数据库关键字，默认false，如果设置为true，根据SqlReservedWords中定义的关键字列表；
一般保留默认值，遇到数据库关键字（Java关键字），使用columnOverride覆盖
-->
<property name="autoDelimitKeywords" value="false"/>
<!-- 生成的Java文件的编码 -->
<property name="javaFileEncoding" value="UTF-8"/>
<!-- 格式化java代码 -->
<property name="javaFormatter" value="org.mybatis.generator.api.dom.DefaultJavaFormatter"/>
<!-- 格式化XML代码 -->
<property name="xmlFormatter" value="org.mybatis.generator.api.dom.DefaultXmlFormatter"/> <!-- beginningDelimiter和endingDelimiter：指明数据库的用于标记数据库对象名的符号，比如ORACLE就是双引号，MYSQL默认是`反引号； -->
<property name="beginningDelimiter" value="`"/>
<property name="endingDelimiter" value="`"/> <!-- 配置pojo的序列化 -->
<plugin type="org.mybatis.generator.plugins.SerializablePlugin" /> <commentGenerator>
<!-- 是否去除自动生成的文档注释 true：是 ： false:否（默认） -->
<property name="suppressAllComments" value="true"/>
<!-- 是否添加数据库注释备注 true：是 false:否（默认） -->
<property name="addRemarkComments" value="true" />
<!-- 是否去除自动生成的时间 true：是 ： false:否（默认） -->
<property name="suppressDate" value="false" />
<!-- 注释时间格式 -->
<property name="dateFormat" value="yyyy-MM-dd HH:mm:ss" />
</commentGenerator> <!-- JDBC 连接 -->
<jdbcConnection driverClass="com.mysql.jdbc.Driver"
connectionURL="jdbc:mysql://mysql.naughty7878.top:3306/test_mybatis?allowPublicKeyRetrieval=true"
userId="hd" password="hd123456">
</jdbcConnection> <!-- java类型处理器
用于处理DB中的类型到Java中的类型，默认使用JavaTypeResolverDefaultImpl；
注意一点，默认会先尝试使用Integer，Long，Short等来对应DECIMAL和 NUMERIC数据类型；
-->
<javaTypeResolver>
<!--
true：使用BigDecimal对应DECIMAL和 NUMERIC数据类型
false：默认,
scale>0;length>18：使用BigDecimal;
scale=0;length[10,18]：使用Long；
scale=0;length[5,9]：使用Integer；
scale=0;length<5：使用Short；
-->
<property name="forceBigDecimals" value="false" />
</javaTypeResolver> <!-- java模型创建器，是必须要的元素
负责：1，key类（见context的defaultModelType）；2，java类；3，查询类
targetPackage：生成的类要放的包，真实的包受enableSubPackages属性控制；
targetProject：目标项目，指定一个存在的目录下，生成的内容会放到指定目录中，如果目录不存在，MBG不会自动建目录
-->
<javaModelGenerator targetPackage="com.test.mybatis.pojo"
targetProject="src/main/java"> <!-- 在targetPackage的基础上，根据数据库的schema再生成一层package，最终生成的类放在这个package下，默认为false -->
<property name="enableSubPackages" value="true" />
<!-- 设置是否在getter方法中，对String类型字段调用trim()方法 -->
<property name="trimStrings" value="false" />
</javaModelGenerator> <!-- 生成SQL map的XML文件生成器，
注意，在Mybatis3之后，我们可以使用mapper.xml文件+Mapper接口（或者不用mapper接口），
或者只使用Mapper接口+Annotation，所以，如果 javaClientGenerator配置中配置了需要生成XML的话，这个元素就必须配置
targetPackage/targetProject:同javaModelGenerator
-->
<sqlMapGenerator targetPackage="mapper"
targetProject="src/main/resources">
<!-- 在targetPackage的基础上，根据数据库的schema再生成一层package，最终生成的类放在这个package下，默认为false -->
<property name="enableSubPackages" value="true" />
</sqlMapGenerator> <!-- 对于mybatis来说，即生成Mapper接口，注意，如果没有配置该元素，那么默认不会生成Mapper接口
targetPackage/targetProject:同javaModelGenerator
type：选择怎么生成mapper接口（在MyBatis3/MyBatis3Simple下）：
1，ANNOTATEDMAPPER：会生成使用Mapper接口+Annotation的方式创建（SQL生成在annotation中），不会生成对应的XML；
2，MIXEDMAPPER：使用混合配置，会生成Mapper接口，并适当添加合适的Annotation，但是XML会生成在XML中；
3，XMLMAPPER：会生成Mapper接口，接口完全依赖XML；
注意，如果context是MyBatis3Simple：只支持ANNOTATEDMAPPER和XMLMAPPER
-->
<javaClientGenerator type="XMLMAPPER"
targetPackage="com.test.mybatis.dao" targetProject="src/main/java">
<property name="enableSubPackages" value="true" />
</javaClientGenerator> <!-- 选择一个table来生成相关文件，可以有一个或多个table，必须要有table元素
选择的table会生成一下文件：
1，SQL map文件
2，生成一个主键类；
3，除了BLOB和主键的其他字段的类；
4，包含BLOB的类；
5，一个用户生成动态查询的条件类（selectByExample, deleteByExample），可选；
6，Mapper接口（可选）
tableName（必要）：要生成对象的表名；
注意：大小写敏感问题。正常情况下，MBG会自动的去识别数据库标识符的大小写敏感度，在一般情况下，MBG会
根据设置的schema，catalog或tablename去查询数据表，按照下面的流程：
1，如果schema，catalog或tablename中有空格，那么设置的是什么格式，就精确的使用指定的大小写格式去查询；
2，否则，如果数据库的标识符使用大写的，那么MBG自动把表名变成大写再查找；
3，否则，如果数据库的标识符使用小写的，那么MBG自动把表名变成小写再查找；
4，否则，使用指定的大小写格式查询；
另外的，如果在创建表的时候，使用的""把数据库对象规定大小写，就算数据库标识符是使用的大写，在这种情况下也会使用给定的大小写来创建表名；
这个时候，请设置delimitIdentifiers="true"即可保留大小写格式；
可选：
1，schema：数据库的schema；
2，catalog：数据库的catalog；
3，alias：为数据表设置的别名，如果设置了alias，那么生成的所有的SELECT SQL语句中，列名会变成：alias_actualColumnName
4，domainObjectName：生成的domain类的名字，如果不设置，直接使用表名作为domain类的名字；可以设置为somepck.domainName，那么会自动把domainName类再放到somepck包里面；
5，enableInsert（默认true）：指定是否生成insert语句；
6，enableSelectByPrimaryKey（默认true）：指定是否生成按照主键查询对象的语句（就是getById或get）；
7，enableSelectByExample（默认true）：MyBatis3Simple为false，指定是否生成动态查询语句；
8，enableUpdateByPrimaryKey（默认true）：指定是否生成按照主键修改对象的语句（即update)；
9，enableDeleteByPrimaryKey（默认true）：指定是否生成按照主键删除对象的语句（即delete）；
10，enableDeleteByExample（默认true）：MyBatis3Simple为false，指定是否生成动态删除语句；
11，enableCountByExample（默认true）：MyBatis3Simple为false，指定是否生成动态查询总条数语句（用于分页的总条数查询）；
12，enableUpdateByExample（默认true）：MyBatis3Simple为false，指定是否生成动态修改语句（只修改对象中不为空的属性）；
13，modelType：参考context元素的defaultModelType，相当于覆盖；
14，delimitIdentifiers：参考tableName的解释，注意，默认的delimitIdentifiers是双引号，如果类似MYSQL这样的数据库，使用的是`（反引号，那么还需要设置context的beginningDelimiter和endingDelimiter属性）
15，delimitAllColumns：设置是否所有生成的SQL中的列名都使用标识符引起来。默认为false，delimitIdentifiers参考context的属性
注意，table里面很多参数都是对javaModelGenerator，context等元素的默认属性的一个复写；
-->
<table schema="test_mybatis" tableName="employee"
domainObjectName="Employee" >
<!-- 如果设置为true，生成的model类会直接使用column本身的名字，而不会再使用驼峰命名方法，比如BORN_DATE，生成的属性名字就是BORN_DATE,而不会是bornDate -->
<property name="useActualColumnNames" value="false" />
<!-- generatedKey用于生成生成主键的方法，
如果设置了该元素，MBG会在生成的<insert>元素中生成一条正确的<selectKey>元素，该元素可选
column:主键的列名；
sqlStatement：要生成的selectKey语句，有以下可选项：
Cloudscape:相当于selectKey的SQL为： VALUES IDENTITY_VAL_LOCAL()
DB2 :相当于selectKey的SQL为： VALUES IDENTITY_VAL_LOCAL()
DB2_MF :相当于selectKey的SQL为：SELECT IDENTITY_VAL_LOCAL() FROM SYSIBM.SYSDUMMY1
Derby :相当于selectKey的SQL为：VALUES IDENTITY_VAL_LOCAL()
HSQLDB :相当于selectKey的SQL为：CALL IDENTITY()
Informix :相当于selectKey的SQL为：select dbinfo('sqlca.sqlerrd1') from systables where tabid=1
MySql :相当于selectKey的SQL为：SELECT LAST_INSERT_ID()
SqlServer :相当于selectKey的SQL为：SELECT SCOPE_IDENTITY()
SYBASE :相当于selectKey的SQL为：SELECT @@IDENTITY
JDBC :相当于在生成的insert元素上添加useGeneratedKeys="true"和keyProperty属性
-->
<generatedKey column="ID" sqlStatement="MySql"
identity="true" />
<!-- 用来修改表中某个列的属性，MBG会使用修改后的列来生成domain的属性；
column:要重新设置的列名；
注意，一个table元素中可以有多个columnOverride元素哈~
-->
<columnOverride column="DATE_FIELD"
property="startDate" />
<!-- ignoreColumn设置一个MGB忽略的列，如果设置了改列，那么在生成的domain中，生成的SQL中，都不会有该列出现
column:指定要忽略的列的名字；
delimitedColumnName：参考table元素的delimitAllColumns配置，默认为false
注意，一个table元素中可以有多个ignoreColumn元素
-->
<ignoreColumn column="dept_id" />
<columnOverride column="gender" jdbcType="VARCHAR" /> </table> </context>
</generatorConfiguration>
c、使用命令：java -jar mybatis-generator-core-1.3.7.jar -configfile mbg.xml -overwrite
d、查看生成目录文件：
package com.test.mybatis.pojo;
public class Employee {
private Integer id;
private String lastName;
private String gender;
private String email;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
}
Employee.java
package com.test.mybatis.pojo; import java.util.ArrayList;
import java.util.List; public class EmployeeExample {
protected String orderByClause; protected boolean distinct; protected List<Criteria> oredCriteria; public EmployeeExample() {
oredCriteria = new ArrayList<Criteria>();
} public void setOrderByClause(String orderByClause) {
this.orderByClause = orderByClause;
} public String getOrderByClause() {
return orderByClause;
} public void setDistinct(boolean distinct) {
this.distinct = distinct;
} public boolean isDistinct() {
return distinct;
} public List<Criteria> getOredCriteria() {
return oredCriteria;
} public void or(Criteria criteria) {
oredCriteria.add(criteria);
} public Criteria or() {
Criteria criteria = createCriteriaInternal();
oredCriteria.add(criteria);
return criteria;
} public Criteria createCriteria() {
Criteria criteria = createCriteriaInternal();
if (oredCriteria.size() == 0) {
oredCriteria.add(criteria);
}
return criteria;
} protected Criteria createCriteriaInternal() {
Criteria criteria = new Criteria();
return criteria;
} public void clear() {
oredCriteria.clear();
orderByClause = null;
distinct = false;
} 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 andIdIsNull() {
addCriterion("id is null");
return (Criteria) this;
} public Criteria andIdIsNotNull() {
addCriterion("id is not null");
return (Criteria) this;
} public Criteria andIdEqualTo(Integer value) {
addCriterion("id =", value, "id");
return (Criteria) this;
} public Criteria andIdNotEqualTo(Integer value) {
addCriterion("id <>", value, "id");
return (Criteria) this;
} public Criteria andIdGreaterThan(Integer value) {
addCriterion("id >", value, "id");
return (Criteria) this;
} public Criteria andIdGreaterThanOrEqualTo(Integer value) {
addCriterion("id >=", value, "id");
return (Criteria) this;
} public Criteria andIdLessThan(Integer value) {
addCriterion("id <", value, "id");
return (Criteria) this;
} public Criteria andIdLessThanOrEqualTo(Integer value) {
addCriterion("id <=", value, "id");
return (Criteria) this;
} public Criteria andIdIn(List<Integer> values) {
addCriterion("id in", values, "id");
return (Criteria) this;
} public Criteria andIdNotIn(List<Integer> values) {
addCriterion("id not in", values, "id");
return (Criteria) this;
} public Criteria andIdBetween(Integer value1, Integer value2) {
addCriterion("id between", value1, value2, "id");
return (Criteria) this;
} public Criteria andIdNotBetween(Integer value1, Integer value2) {
addCriterion("id not between", value1, value2, "id");
return (Criteria) this;
} public Criteria andLastNameIsNull() {
addCriterion("last_name is null");
return (Criteria) this;
} public Criteria andLastNameIsNotNull() {
addCriterion("last_name is not null");
return (Criteria) this;
} public Criteria andLastNameEqualTo(String value) {
addCriterion("last_name =", value, "lastName");
return (Criteria) this;
} public Criteria andLastNameNotEqualTo(String value) {
addCriterion("last_name <>", value, "lastName");
return (Criteria) this;
} public Criteria andLastNameGreaterThan(String value) {
addCriterion("last_name >", value, "lastName");
return (Criteria) this;
} public Criteria andLastNameGreaterThanOrEqualTo(String value) {
addCriterion("last_name >=", value, "lastName");
return (Criteria) this;
} public Criteria andLastNameLessThan(String value) {
addCriterion("last_name <", value, "lastName");
return (Criteria) this;
} public Criteria andLastNameLessThanOrEqualTo(String value) {
addCriterion("last_name <=", value, "lastName");
return (Criteria) this;
} public Criteria andLastNameLike(String value) {
addCriterion("last_name like", value, "lastName");
return (Criteria) this;
} public Criteria andLastNameNotLike(String value) {
addCriterion("last_name not like", value, "lastName");
return (Criteria) this;
} public Criteria andLastNameIn(List<String> values) {
addCriterion("last_name in", values, "lastName");
return (Criteria) this;
} public Criteria andLastNameNotIn(List<String> values) {
addCriterion("last_name not in", values, "lastName");
return (Criteria) this;
} public Criteria andLastNameBetween(String value1, String value2) {
addCriterion("last_name between", value1, value2, "lastName");
return (Criteria) this;
} public Criteria andLastNameNotBetween(String value1, String value2) {
addCriterion("last_name not between", value1, value2, "lastName");
return (Criteria) this;
} public Criteria andGenderIsNull() {
addCriterion("gender is null");
return (Criteria) this;
} public Criteria andGenderIsNotNull() {
addCriterion("gender is not null");
return (Criteria) this;
} public Criteria andGenderEqualTo(String value) {
addCriterion("gender =", value, "gender");
return (Criteria) this;
} public Criteria andGenderNotEqualTo(String value) {
addCriterion("gender <>", value, "gender");
return (Criteria) this;
} public Criteria andGenderGreaterThan(String value) {
addCriterion("gender >", value, "gender");
return (Criteria) this;
} public Criteria andGenderGreaterThanOrEqualTo(String value) {
addCriterion("gender >=", value, "gender");
return (Criteria) this;
} public Criteria andGenderLessThan(String value) {
addCriterion("gender <", value, "gender");
return (Criteria) this;
} public Criteria andGenderLessThanOrEqualTo(String value) {
addCriterion("gender <=", value, "gender");
return (Criteria) this;
} public Criteria andGenderLike(String value) {
addCriterion("gender like", value, "gender");
return (Criteria) this;
} public Criteria andGenderNotLike(String value) {
addCriterion("gender not like", value, "gender");
return (Criteria) this;
} public Criteria andGenderIn(List<String> values) {
addCriterion("gender in", values, "gender");
return (Criteria) this;
} public Criteria andGenderNotIn(List<String> values) {
addCriterion("gender not in", values, "gender");
return (Criteria) this;
} public Criteria andGenderBetween(String value1, String value2) {
addCriterion("gender between", value1, value2, "gender");
return (Criteria) this;
} public Criteria andGenderNotBetween(String value1, String value2) {
addCriterion("gender not between", value1, value2, "gender");
return (Criteria) this;
} public Criteria andEmailIsNull() {
addCriterion("email is null");
return (Criteria) this;
} public Criteria andEmailIsNotNull() {
addCriterion("email is not null");
return (Criteria) this;
} public Criteria andEmailEqualTo(String value) {
addCriterion("email =", value, "email");
return (Criteria) this;
} public Criteria andEmailNotEqualTo(String value) {
addCriterion("email <>", value, "email");
return (Criteria) this;
} public Criteria andEmailGreaterThan(String value) {
addCriterion("email >", value, "email");
return (Criteria) this;
} public Criteria andEmailGreaterThanOrEqualTo(String value) {
addCriterion("email >=", value, "email");
return (Criteria) this;
} public Criteria andEmailLessThan(String value) {
addCriterion("email <", value, "email");
return (Criteria) this;
} public Criteria andEmailLessThanOrEqualTo(String value) {
addCriterion("email <=", value, "email");
return (Criteria) this;
} public Criteria andEmailLike(String value) {
addCriterion("email like", value, "email");
return (Criteria) this;
} public Criteria andEmailNotLike(String value) {
addCriterion("email not like", value, "email");
return (Criteria) this;
} public Criteria andEmailIn(List<String> values) {
addCriterion("email in", values, "email");
return (Criteria) this;
} public Criteria andEmailNotIn(List<String> values) {
addCriterion("email not in", values, "email");
return (Criteria) this;
} public Criteria andEmailBetween(String value1, String value2) {
addCriterion("email between", value1, value2, "email");
return (Criteria) this;
} public Criteria andEmailNotBetween(String value1, String value2) {
addCriterion("email not between", value1, value2, "email");
return (Criteria) this;
}
} public static class Criteria extends GeneratedCriteria { protected Criteria() {
super();
}
} 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);
}
}
}
EmployeeExample.java
package com.test.mybatis.dao; import com.test.mybatis.pojo.Employee;
import com.test.mybatis.pojo.EmployeeExample;
import java.util.List;
import org.apache.ibatis.annotations.Param; public interface EmployeeMapper {
long countByExample(EmployeeExample example); int deleteByExample(EmployeeExample example); int deleteByPrimaryKey(Integer id); int insert(Employee record); int insertSelective(Employee record); List<Employee> selectByExample(EmployeeExample example); Employee selectByPrimaryKey(Integer id); int updateByExampleSelective(@Param("record") Employee record, @Param("example") EmployeeExample example); int updateByExample(@Param("record") Employee record, @Param("example") EmployeeExample example); int updateByPrimaryKeySelective(Employee record); int updateByPrimaryKey(Employee record);
}
EmployeeMapper.java
<?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.test.mybatis.dao.EmployeeMapper">
<resultMap id="BaseResultMap" type="com.test.mybatis.pojo.Employee">
<id column="id" jdbcType="INTEGER" property="id" />
<result column="last_name" jdbcType="VARCHAR" property="lastName" />
<result column="gender" jdbcType="VARCHAR" property="gender" />
<result column="email" jdbcType="VARCHAR" property="email" />
</resultMap>
<sql id="Example_Where_Clause">
<where>
<foreach collection="oredCriteria" item="criteria" separator="or">
<if test="criteria.valid">
<trim prefix="(" prefixOverrides="and" suffix=")">
<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 close=")" collection="criterion.value" item="listItem" open="(" separator=",">
#{listItem}
</foreach>
</when>
</choose>
</foreach>
</trim>
</if>
</foreach>
</where>
</sql>
<sql id="Update_By_Example_Where_Clause">
<where>
<foreach collection="example.oredCriteria" item="criteria" separator="or">
<if test="criteria.valid">
<trim prefix="(" prefixOverrides="and" suffix=")">
<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 close=")" collection="criterion.value" item="listItem" open="(" separator=",">
#{listItem}
</foreach>
</when>
</choose>
</foreach>
</trim>
</if>
</foreach>
</where>
</sql>
<sql id="Base_Column_List">
id, last_name, gender, email
</sql>
<select id="selectByExample" parameterType="com.test.mybatis.pojo.EmployeeExample" resultMap="BaseResultMap">
select
<if test="distinct">
distinct
</if>
<include refid="Base_Column_List" />
from employee
<if test="_parameter != null">
<include refid="Example_Where_Clause" />
</if>
<if test="orderByClause != null">
order by ${orderByClause}
</if>
</select>
<select id="selectByPrimaryKey" parameterType="java.lang.Integer" resultMap="BaseResultMap">
select
<include refid="Base_Column_List" />
from employee
where id = #{id,jdbcType=INTEGER}
</select>
<delete id="deleteByPrimaryKey" parameterType="java.lang.Integer">
delete from employee
where id = #{id,jdbcType=INTEGER}
</delete>
<delete id="deleteByExample" parameterType="com.test.mybatis.pojo.EmployeeExample">
delete from employee
<if test="_parameter != null">
<include refid="Example_Where_Clause" />
</if>
</delete>
<insert id="insert" parameterType="com.test.mybatis.pojo.Employee">
<selectKey keyProperty="id" order="AFTER" resultType="java.lang.Integer">
SELECT LAST_INSERT_ID()
</selectKey>
insert into employee (last_name, gender, email
)
values (#{lastName,jdbcType=VARCHAR}, #{gender,jdbcType=VARCHAR}, #{email,jdbcType=VARCHAR}
)
</insert>
<insert id="insertSelective" parameterType="com.test.mybatis.pojo.Employee">
<selectKey keyProperty="id" order="AFTER" resultType="java.lang.Integer">
SELECT LAST_INSERT_ID()
</selectKey>
insert into employee
<trim prefix="(" suffix=")" suffixOverrides=",">
<if test="lastName != null">
last_name,
</if>
<if test="gender != null">
gender,
</if>
<if test="email != null">
email,
</if>
</trim>
<trim prefix="values (" suffix=")" suffixOverrides=",">
<if test="lastName != null">
#{lastName,jdbcType=VARCHAR},
</if>
<if test="gender != null">
#{gender,jdbcType=VARCHAR},
</if>
<if test="email != null">
#{email,jdbcType=VARCHAR},
</if>
</trim>
</insert>
<select id="countByExample" parameterType="com.test.mybatis.pojo.EmployeeExample" resultType="java.lang.Long">
select count(*) from employee
<if test="_parameter != null">
<include refid="Example_Where_Clause" />
</if>
</select>
<update id="updateByExampleSelective" parameterType="map">
update employee
<set>
<if test="record.id != null">
id = #{record.id,jdbcType=INTEGER},
</if>
<if test="record.lastName != null">
last_name = #{record.lastName,jdbcType=VARCHAR},
</if>
<if test="record.gender != null">
gender = #{record.gender,jdbcType=VARCHAR},
</if>
<if test="record.email != null">
email = #{record.email,jdbcType=VARCHAR},
</if>
</set>
<if test="_parameter != null">
<include refid="Update_By_Example_Where_Clause" />
</if>
</update>
<update id="updateByExample" parameterType="map">
update employee
set id = #{record.id,jdbcType=INTEGER},
last_name = #{record.lastName,jdbcType=VARCHAR},
gender = #{record.gender,jdbcType=VARCHAR},
email = #{record.email,jdbcType=VARCHAR}
<if test="_parameter != null">
<include refid="Update_By_Example_Where_Clause" />
</if>
</update>
<update id="updateByPrimaryKeySelective" parameterType="com.test.mybatis.pojo.Employee">
update employee
<set>
<if test="lastName != null">
last_name = #{lastName,jdbcType=VARCHAR},
</if>
<if test="gender != null">
gender = #{gender,jdbcType=VARCHAR},
</if>
<if test="email != null">
email = #{email,jdbcType=VARCHAR},
</if>
</set>
where id = #{id,jdbcType=INTEGER}
</update>
<update id="updateByPrimaryKey" parameterType="com.test.mybatis.pojo.Employee">
update employee
set last_name = #{lastName,jdbcType=VARCHAR},
gender = #{gender,jdbcType=VARCHAR},
email = #{email,jdbcType=VARCHAR}
where id = #{id,jdbcType=INTEGER}
</update>
</mapper>
EmployeeMapper.xml
2、使用java代码方式
a、pom中引入mybatis-generator-core依赖
<dependency>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-core</artifactId>
<version>1.3.7</version>
</dependency>
b、代码
package com.test.mybatis.generator; import java.io.InputStream;
import java.util.ArrayList;
import java.util.List; import org.apache.ibatis.io.Resources;
import org.mybatis.generator.api.MyBatisGenerator;
import org.mybatis.generator.config.Configuration;
import org.mybatis.generator.config.xml.ConfigurationParser;
import org.mybatis.generator.internal.DefaultShellCallback; public class TestMBG { public static void main(String[] args) throws Exception {
List<String> warnings = new ArrayList<String>();
boolean overwrite = true;
// File configFile = new File("mbg.xml");
InputStream inputStream = Resources.getResourceAsStream("mbg.xml"); ConfigurationParser cp = new ConfigurationParser(warnings);
Configuration config = cp.parseConfiguration(inputStream);
DefaultShellCallback callback = new DefaultShellCallback(overwrite);
MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings);
myBatisGenerator.generate(null);
}
}
3、使用maven插件mybatis-generator-plus
a、pom文件
<build>
<plugins>
<plugin>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-maven-plugin</artifactId>
<version>1.3.7</version>
<dependencies>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.13</version>
</dependency>
</dependencies>
<configuration>
<!-- mybatis用于生成代码的配置文件 -->
<configurationFile>src/main/resources/mbg.xml</configurationFile>
<verbose>true</verbose>
<overwrite>true</overwrite>
</configuration>
</plugin>
</plugins>
</build>
b、mvn命令：mybatis-generator:generate
