14.通用Mapper中的方法详解
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package cn.itcast.mybatis.mapper;import static org.junit.Assert.*;import java.io.InputStream;import java.util.ArrayList;import java.util.Date;import java.util.List;import javax.persistence.Id;import net.sf.jsqlparser.statement.update.Update;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 org.apache.log4j.lf5.util.Resource;import org.junit.Before;import org.junit.Test;import com.github.abel533.entity.Example;import cn.itcast.mybatis.pojo.User;public class NewUserMapperTest { private NewUserMapper newUserMapper; @Before public void setUp() throws Exception {// 完成mybatis的初始化 InputStream inputStream=Resources.getResourceAsStream("mybatis-config.xml"); SqlSessionFactory sqlSessionFactory=new SqlSessionFactoryBuilder().build(inputStream); SqlSession session=sqlSessionFactory.openSession(true); this.newUserMapper=session.getMapper(NewUserMapper.class); } @Test public void testSelectOne() {// 根据用户名和密码查询一条数据 User record=new User(); record.setName("王五"); record.setPassword("123456"); User user = this.newUserMapper.selectOne(record); System.out.println(user); /** * Preparing: SELECT USER_NAME USERNAME,NAME,UPDATED,PASSWORD,ID,BIRTHDAY,SEX,AGE,CREATED FROM tb_user WHERE NAME = ? AND PASSWORD = ? * Parameters: 王五(String), 123456(String) */ } @Test public void testSelect() {// 用于查询多条符合条件的数据,如果无查询条件就设置为null,表示查询所有的数据；// 如果要设置条件，就实例化user，设置条件即可 User record=new User(); record.setSex(1); List<User> list=this.newUserMapper.select(record);// List<User> list = this.newUserMapper.select(null); for(User user:list){ System.out.println(user);; } /** * Preparing: SELECT USER_NAME USERNAME,NAME,PASSWORD,BIRTHDAY,UPDATED,SEX,AGE,CREATED,ID FROM tb_user WHERE SEX = ? * Parameters: 1(Integer) */ } @Test public void testSelectCount() {// 查询数据总条数设置为null,若按条件查询总条数可以设置条件// 比如，查询性别为男性1的数据总条数 User record=new User(); record.setSex(1); System.out.println(this.newUserMapper.selectCount(record)); /** * Preparing: SELECT COUNT(*) FROM tb_user WHERE SEX = ? */// System.out.println(this.newUserMapper.selectCount(null)); /** * Preparing: SELECT COUNT(*) FROM tb_user */ } @Test public void testSelectByPrimaryKey() {// 按主键查询数据，注意是根据主键，而不是id User user = this.newUserMapper.selectByPrimaryKey(2L); System.out.println(user); /** * 例如pojo中@Id若放在name属性上 * @Id * private String userName; * 那么主键就是userName，就按userName进行查询而不是id */ }//======================================================================================== @Test public void testInsert() { User user=new User(); user.setAge(22); user.setName("test_1"); user.setSex(2); user.setPassword("222"); user.setUserName("test_1_username"); this.newUserMapper.insert(user); System.out.println(user.getId()); /** * Preparing: INSERT INTO tb_user (USER_NAME,NAME,CREATED,UPDATED,PASSWORD,SEX,ID,AGE,BIRTHDAY) VALUES ( ?,?,?,?,?,?,?,?,? ) * Parameters: test_1_username(String), test_1(String), null, null, 222(String), 2(Integer), null, 22(Integer), null * * Executing: SELECT LAST_INSERT_ID() */ } @Test public void testInsertSelective() { User user=new User(); user.setUserName("test_3_username"); this.newUserMapper.insertSelective(user); System.out.println(user.getId()); /** * Preparing: INSERT INTO tb_user ( USER_NAME,ID ) VALUES ( ?,? ) * Parameters: test_3_username(String), null */ }//================================================================================= /** * 总结insert()与InsertSelective()的区别： * insert是无论你的插入的属性字段是否为null都会作为一个字段去插入 * insertSelective是当你插入的属性值不为null时才作为一个字段去插入 * 详细对比两者的插入语句就可以发现。 *///================================================================================= @Test public void testDelete() {// 可以根据属性去删除，也可以设置为null把所有数据都删除 User user=new User(); user.setName("test_1"); this.newUserMapper.delete(user); /** * Preparing: DELETE FROM tb_user WHERE NAME = ? * Parameters: test_1(String) * Updates: 1 */// this.newUserMapper.delete(null); } @Test public void testDeleteByPrimaryKey() {// 根据主键删除数据，只删除一条 this.newUserMapper.deleteByPrimaryKey(12L); /** * Preparing: DELETE FROM tb_user WHERE (ID = ? ) * Parameters: 12(Long) * Updates: 1 * */ } @Test public void testUpdateByPrimaryKey() {// 根据主键进行更新 User user=new User(); user.setId(13L); user.setName("13"); user.setUserName("13"); this.newUserMapper.updateByPrimaryKey(user); /** * Preparing: UPDATE tb_user SET USER_NAME = ?, NAME = ?, PASSWORD = ?, BIRTHDAY = ?, CREATED = ?, AGE = ?, UPDATED = ?, SEX = ? WHERE ID = ? * Parameters: 13(String), 13(String), null, null, null, null, null, null, 13(Long) * Updates: 1 */ } @Test public void testUpdateByPrimaryKeySelective() {// 根据主键更新不为null的字段// 例如修改用户密码 User user=new User(); user.setId(2L); user.setPassword("123456789"); user.setUpdated(new Date()); this.newUserMapper.updateByPrimaryKeySelective(user); /** * Preparing: UPDATE tb_user SET UPDATED = ?, PASSWORD = ? WHERE ID = ? * Parameters: 2017-11-17 13:27:04.334(Timestamp), 123456789(String), 2(Long) * Updates: 1 */ } // 以下都是ByExample，比较复杂但是却很灵活，可以解决如下需求 /** * 需求： * 1、查询用户列表并且按照更新时间倒序排序 * 2、根据多个id查询用户数据 * 3、批量删除数据 */ @Test public void testSelectCountByExample() { fail("Not yet implemented"); } @Test public void testDeleteByExample() {// 3、批量删除数据 Example example =new Example(User.class); List<Object> list = new ArrayList<Object>(); list.add(2); list.add(2); example.createCriteria().andIn("sex",list); this.newUserMapper.deleteByExample(example); /** * 只可以用于单表删除，如果你要删除的数据与另一张表有关联，那么无法删除 */ } @Test public void testSelectByExample() { // 1、查询用户列表并且按照更新时间倒序排序 Example example=new Example(User.class); example.setOrderByClause("updated DESC"); List<User> list = this.newUserMapper.selectByExample(example); for(User user:list){ System.out.println(user); } /** * Preparing: SELECT USER_NAME USERNAME,BIRTHDAY,NAME,AGE,PASSWORD,CREATED,ID,SEX,UPDATED FROM tb_user order by updated DESC * Total: 10 * * * User [id=2, userName=lisi, password=123456789, name=李四, age=21, sex=2, birthday=Tue Jan 01 00:00:00 CST 1991, created=Fri Sep 19 16:56:04 CST 2014, updated=Fri Nov 17 13:27:04 CST 2017] * User [id=1, userName=null, password=abc123, name=null, age=null, sex=null, birthday=null, created=null, updated=Mon Jul 31 18:33:00 CST 2017] * User [id=6, userName=lilei, password=123456, name=李磊, age=23, sex=1, birthday=Mon Aug 08 00:00:00 CDT 1988, created=Sat Sep 20 11:41:15 CST 2014, updated=Sat Sep 20 11:41:15 CST 2014] * User [id=4, userName=zhangwei, password=123456, name=张伟, age=20, sex=1, birthday=Thu Sep 01 00:00:00 CDT 1988, created=Fri Sep 19 16:56:04 CST 2014, updated=Fri Sep 19 16:56:04 CST 2014] * User [id=5, userName=lina, password=123456, name=李娜, age=28, sex=1, birthday=Tue Jan 01 00:00:00 CST 1985, created=Fri Sep 19 16:56:04 CST 2014, updated=Fri Sep 19 16:56:04 CST 2014] * User [id=3, userName=wangwu, password=123456, name=王五, age=22, sex=2, birthday=Sun Jan 01 00:00:00 CST 1989, created=Fri Sep 19 16:56:04 CST 2014, updated=Fri Sep 19 16:56:04 CST 2014] * User [id=7, userName=null, password=null, name=sansan, age=null, sex=null, birthday=null, created=null, updated=null] * User [id=8, userName=null, password=null, name=test_insertSelective, age=null, sex=null, birthday=null, created=null, updated=null] * User [id=9, userName=null, password=null, name=sansan, age=null, sex=null, birthday=null, created=null, updated=null] * User [id=13, userName=13, password=null, name=13, age=null, sex=null, birthday=null, created=null, updated=null] */ } @Test public void testSelectByExample2() {// 2、根据多个id查询用户数据 Example example =new Example(User.class);// 创建查询条件 List<Object> ids = new ArrayList<Object>(); ids.add(1L); ids.add(2L); ids.add(13L); example.createCriteria().andIn("id", ids); List<User> list = this.newUserMapper.selectByExample(example); for(User user:list){ System.out.println(user); } /** *Preparing: SELECT USER_NAME USERNAME,NAME,BIRTHDAY,PASSWORD,SEX,UPDATED,CREATED,ID,AGE FROM tb_user WHERE ( ID in(?,?,?) ) * Parameters: 1(Long), 2(Long), 13(Long) * Total: 3 * * User [id=1, userName=null, password=abc123, name=null, age=null, sex=null, birthday=null, created=null, updated=Mon Jul 31 18:33:00 CST 2017] * User [id=2, userName=lisi, password=123456789, name=李四, age=21, sex=2, birthday=Tue Jan 01 00:00:00 CST 1991, created=Fri Sep 19 16:56:04 CST 2014, updated=Fri Nov 17 13:27:04 CST 2017] * User [id=13, userName=13, password=null, name=13, age=null, sex=null, birthday=null, created=null, updated=null] */ } @Test public void testUpdateByExampleSelective() { fail("Not yet implemented"); } @Test public void testUpdateByExample() { fail("Not yet implemented"); }}阅读全文
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