MyBatis练习：统计每日比赛胜负场次
我的电脑操作系统版本为Win7旗舰版（ServicePack1），Oracle版本为Oracle11g
程序使用的jar包有：mybatis-3.2.2.jar、ojdbc14-10.2.0.2.0.jar
本例中使用的配置文件mybatis-config.xml，可以参见我的另一篇Blog《一个简单的MyBatis连接Oracle数据库的例子》（http://my.oschina.net/Tsybius2014/blog/626206）
现在Oracle数据库中建立一个新表GAME_RECORD并插入一些数据，SQL如下：
CREATE TABLE GAME_RECORD ( ID NUMBER(12, 0) PRIMARY KEY, GAME_DATE NUMBER(10, 0), PLAYER_NAME VARCHAR(10), GAME_RESULT VARCHAR(10) ); INSERT INTO GAME_RECORD (ID, GAME_DATE, PLAYER_NAME, GAME_RESULT) VALUES (1, 20160301, 'Tsybius', 'WIN'); INSERT INTO GAME_RECORD (ID, GAME_DATE, PLAYER_NAME, GAME_RESULT) VALUES (2, 20160301, 'Tsybius', 'LOSE'); INSERT INTO GAME_RECORD (ID, GAME_DATE, PLAYER_NAME, GAME_RESULT) VALUES (3, 20160301, 'Tsybius', 'LOSE'); INSERT INTO GAME_RECORD (ID, GAME_DATE, PLAYER_NAME, GAME_RESULT) VALUES (4, 20160302, 'Tsybius', 'WIN'); INSERT INTO GAME_RECORD (ID, GAME_DATE, PLAYER_NAME, GAME_RESULT) VALUES (5, 20160302, 'Tsybius', 'WIN'); INSERT INTO GAME_RECORD (ID, GAME_DATE, PLAYER_NAME, GAME_RESULT) VALUES (6, 20160302, 'Tsybius', 'LOSE'); INSERT INTO GAME_RECORD (ID, GAME_DATE, PLAYER_NAME, GAME_RESULT) VALUES (7, 20160302, 'Tsybius', 'DRAW'); INSERT INTO GAME_RECORD (ID, GAME_DATE, PLAYER_NAME, GAME_RESULT) VALUES (8, 20160302, 'Tsybius', 'WIN'); INSERT INTO GAME_RECORD (ID, GAME_DATE, PLAYER_NAME, GAME_RESULT) VALUES (9, 20160302, 'Tsybius', 'LOSE'); INSERT INTO GAME_RECORD (ID, GAME_DATE, PLAYER_NAME, GAME_RESULT) VALUES (10, 20160303, 'Tsybius', 'WIN'); INSERT INTO GAME_RECORD (ID, GAME_DATE, PLAYER_NAME, GAME_RESULT) VALUES (11, 20160303, 'Tsybius', 'DRAW'); INSERT INTO GAME_RECORD (ID, GAME_DATE, PLAYER_NAME, GAME_RESULT) VALUES (12, 20160303, 'Quintus', 'WIN'); INSERT INTO GAME_RECORD (ID, GAME_DATE, PLAYER_NAME, GAME_RESULT) VALUES (13, 20160303, 'Quintus', 'WIN'); COMMIT; /
数据表建立后，从PL/SQL上查询到的结果集如下：
现在我们要做的，是统计出玩家Tsybius每日的胜（WIN）、负（LOSE）和平局（DRAW）场次
在PL/SQL中，我先写了一个SQL：
SELECT DT.GAME_DATE, NVL(WN.WIN_CNT, 0) AS WIN, NVL(LS.LOSE_CNT, 0) AS LOSE, NVL(DRW.DRAW_CNT, 0) AS DRAW FROM ((SELECT GAME_DATE FROM GAME_RECORD WHERE PLAYER_NAME = 'Tsybius' GROUP BY GAME_DATE) DT LEFT JOIN (SELECT GAME_DATE, COUNT(*) AS WIN_CNT FROM GAME_RECORD WHERE GAME_RESULT = 'WIN' AND PLAYER_NAME = 'Tsybius' GROUP BY GAME_DATE) WN ON DT.GAME_DATE = WN.GAME_DATE LEFT JOIN (SELECT GAME_DATE, COUNT(*) AS LOSE_CNT FROM GAME_RECORD WHERE GAME_RESULT = 'LOSE' AND PLAYER_NAME = 'Tsybius' GROUP BY GAME_DATE) LS ON DT.GAME_DATE = LS.GAME_DATE LEFT JOIN (SELECT GAME_DATE, COUNT(*) AS DRAW_CNT FROM GAME_RECORD WHERE GAME_RESULT = 'DRAW' AND PLAYER_NAME = 'Tsybius' GROUP BY GAME_DATE) DRW ON DT.GAME_DATE = DRW.GAME_DATE) ORDER BY DT.GAME_DATE
这个SQL的查询结果如下：
现在将这个SQL语句移植到MyBatis中，main函数调用代码如下：
import java.io.InputStream;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
/**
* MyBatis使用测试
* @author Tsybius2014
* @date 2016年3月16日
* @time 下午1:55:28
* @remark
*
*/
public class MyBatisTest {
public static void main(String[] args) {
try {
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
SqlSession session = sqlSessionFactory.openSession();
try {
GameRecordMapper mapper = session.getMapper(GameRecordMapper.class);
//获取每日胜、负、平局场次
List<Map<String, Object>> gameLogList = mapper.getGameLog("Tsybius");
Iterator<Map<String, Object>> iter = gameLogList.iterator();
while (iter.hasNext()) {
Map<String, Object> gameLog = iter.next();
System.out.println(gameLog);
}
} finally {
session.close();
}
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
GameRecordMapper.java代码如下：
import java.util.List;
import java.util.Map;
public interface GameRecordMapper {
/**
* 获取指定选手每日胜、负、平局的场次统计信息
* @param playerName 选手名
* @return
*/
List<Map<String, Object>> getGameLog(String playerName);
}
GameRecordMapper.xml代码如下：
<?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="GameRecordMapper">
<resultMap id="GameLogMap" type="java.util.Map" >
<result column="GAME_DATE" property="gameDate" jdbcType="DECIMAL" />
<result column="WIN" property="win" jdbcType="DECIMAL" />
<result column="LOSE" property="lose" jdbcType="DECIMAL" />
<result column="DRAW" property="draw" jdbcType="DECIMAL" />
</resultMap>
<sql id="Calc_Win_Times" >
SELECT GAME_DATE, COUNT(*) AS WIN_CNT
FROM GAME_RECORD
WHERE GAME_RESULT = 'WIN' AND PLAYER_NAME = #{playerName, jdbcType = VARCHAR}
GROUP BY GAME_DATE
</sql>
<sql id="Calc_Lose_Times" >
SELECT GAME_DATE, COUNT(*) AS LOSE_CNT
FROM GAME_RECORD
WHERE GAME_RESULT = 'LOSE' AND PLAYER_NAME = #{playerName, jdbcType = VARCHAR}
GROUP BY GAME_DATE
</sql>
<sql id="Calc_Draw_Times" >
SELECT GAME_DATE, COUNT(*) AS DRAW_CNT
FROM GAME_RECORD
WHERE GAME_RESULT = 'DRAW' AND PLAYER_NAME = #{playerName, jdbcType = VARCHAR}
GROUP BY GAME_DATE
</sql>
<select id="getGameLog" parameterType="java.lang.String" resultMap="GameLogMap" >
SELECT DT.GAME_DATE, NVL(WN.WIN_CNT, 0) AS WIN, NVL(LS.LOSE_CNT, 0) AS LOSE, NVL(DRW.DRAW_CNT, 0) AS DRAW
FROM ((SELECT GAME_DATE
FROM GAME_RECORD
WHERE PLAYER_NAME = #{playerName, jdbcType = VARCHAR}
GROUP BY GAME_DATE) DT
LEFT JOIN (<include refid="Calc_Win_Times" />) WN ON DT.GAME_DATE = WN.GAME_DATE
LEFT JOIN (<include refid="Calc_Lose_Times" />) LS ON DT.GAME_DATE = LS.GAME_DATE
LEFT JOIN (<include refid="Calc_Draw_Times" />) DRW ON DT.GAME_DATE = DRW.GAME_DATE)
ORDER BY DT.GAME_DATE
</select>
</mapper>
程序运行时，输出到控制台中的代码如下：
{gameDate=20160301, lose=2, draw=0, win=1}
{gameDate=20160302, lose=2, draw=1, win=3}
{gameDate=20160303, lose=0, draw=1, win=1}
END