ibatis基本操作
import java.util.List; import org.apache.ibatis.annotations.Delete; import org.apache.ibatis.annotations.Insert; import org.apache.ibatis.annotations.Mapper; import org.apache.ibatis.annotations.Select; import org.apache.ibatis.annotations.Update; import org.apache.ibatis.annotations.Param; @Mapper public interface FileMappigMapper {String selectSql = "SELECT URL, DOWNLOAD_SIZE,"+ " DATE_FORMAT(EXPIRES_TIME, '%Y-%m-%d %H:%i:%s') AS EXPIRES_TIME,"+ " FROM FILE_MAPPING ";@Select(selectSql + " WHERE EXPIRES_TIME <= #{expiresTime}")List<FileInfo> listFileMappingBefore(@Param("expiresTime") String expiresTime);@Insert("INSERT INTO FILE_MAPPING(URL, DOWNLOAD_SIZE, DOWNLOAD_TIME) VALUES (\n"+ " #{url}, #{downloadSize}, #{downloadTime})")int addFileMapping(FileInfo file);@Update("UPDATE FILE_MAPPING SET EXPIRES_TIME=#{expiresTime}, UPDATED_TIME = CURRENT_TIMESTAMP WHERE URL=#{url}")int updateFileExpireTime(@Param("url") String url, @Param("expiresTime") String expiresTime);@Delete("DELETE FROM FILE_MAPPING WHERE URL=#{url}")int deleteFileMapping(String url); }
JSON字段提取函数json_extract 及 sql集合操作示例
@Select("SELECT SUM(json_extract(CONTENT_JSON, '$.bitrate')) from SESSION "+ " WHERE CATEGORY='abc' and SERVICE_ID in (${serviceIdList})")public Integer getTotalRequestBitrate(@Param("serviceIdList") String serviceIdList);
将Java非基本类型映射到数据库的某个字符串字段中存储
将复杂Java类转换为JSON字符串,用于存储到数据库中
@Update("UPDATE SESSION SET "+ " STATUS_DETAIL=#{detail,typeHandler=io.example.scheduler.mapper.JsonTypeHandler},"+ " UPDATED_TIME = CURRENT_TIMESTAMP WHERE GTSI = #{gtsi}")public int updateSession(@Param("gtsi") String gtsi, @Param("detail") StatusDetail detail);@Select("SELECT * FROM SESSION")@ResultMap("jobResult")public List<Job> listJob();
相应的在读取数据库时，需要将对应字符串转换为该复杂类，因此需要定义映射文件
<?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="io.castera.datacastScheduler.mapper.NrtSessionInfoMapper"><resultMap id="jobResult" type="com.example.scheduler.Job" autoMapping="true"><result property="statusDetail" column="STATUS_DETAIL"javaType=""com.example.scheduler.StatusDetail"typeHandler=""com.example.scheduler.mapper.JsonTypeHandler"/></resultMap> </mapper>
注意“将复杂Java类转换为JSON字符串”时，需要类型转换类
package com.example.scheduler.mapper;import com.fasterxml.jackson.core.JsonProcessingException; import java.sql.CallableStatement; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import org.apache.ibatis.type.JdbcType; import org.apache.ibatis.type.TypeHandler;public class JsonTypeHandler<T> implements TypeHandler<T> {private Class<T> dataClass;public JsonTypeHandler(Class<T> dataClass) {if (dataClass == null)throw new IllegalArgumentException("should provide typeClass");this.dataClass = dataClass;}@Overridepublic void setParameter(PreparedStatement ps, int i, T parameter, JdbcType jdbcType) throws SQLException {try {ps.setString(i, parameter== null ? null : Utils.writerSnake.writeValueAsString(parameter));} catch (JsonProcessingException e) {ps.setString(i, null);}}@Overridepublic T getResult(ResultSet rs, String columnName) throws SQLException {return parseString(rs.getString(columnName));}@Overridepublic T getResult(ResultSet rs, int columnIndex) throws SQLException {return parseString(rs.getString(columnIndex));}@Overridepublic T getResult(CallableStatement cs, int columnIndex) throws SQLException {return parseString(cs.getString(columnIndex));}private T parseString(String value) {if (value == null || value.isBlank())return null;try {return Utils.mapperSnake.readValue(value, dataClass);} catch (JsonProcessingException e) {throw new RuntimeException(e);}} }
将Java非基本类型class展开存储为数据表的多个字段
当属性为非Java基本类型class，但想展开存储在数据库时，比如如下类
@JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class) public class Schedule {public Recurrence recurrence;public ExtraInfo extraInfo = new ExtraInfo(); }public class Recurrence {public Integer type； @JsonInclude(value = JsonInclude.Include.CUSTOM, valueFilter = JsonIgnoreNumberFilter.class)public int dailyInterval = 0;@JsonProperty("week_days")public List<String> weekDays; public int monthlyType = 0; }
想展开存储为如下数据库字段
CREATE TABLE SCHEDULE (RECURRENCE_TYPE int(11) DEFAULT NULL,DAILY_INTERVAL int(11) DEFAULT NULL,WEEK_DAYS varchar(128) DEFAULT NULL,MONTHLY_TYPE int(11) DEFAULT NULL, ) DEFAULT CHARSET = utf8;
那么当读取数据库时，需要将相关字段合并为原来的属性类，需要用到resultMap和association
<?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.example.scheduler.mapper.ScheduleMapper"><resultMap id="scheduleResult" type="com.example.scheduler.model.Schedule" autoMapping="true"><result property="extraInfo" column="EXTRA_INFO_JSON"javaType="com.example.scheduler.ExtraInfo"typeHandler="com.example.scheduler.mapper.JsonTypeHandler"/><association property="recurrence" notNullColumn="RECURRENCE_TYPE"javaType="com.example.scheduler.model.Recurrence"><result property="type" column="RECURRENCE_TYPE"/><result property="dailyInterval" column="DAILY_INTERVAL"/><result property="monthlyType" column="MONTHLY_TYPE"/><result property="weekDays" column="WEEK_DAYS" typeHandler="com.example.scheduler.mapper.StringListTypeHandler"/></association></resultMap> </mapper>
注意“result” 和“association”的区别：
result定义数据库中的某个字段与对应属性的类的定义
association将数据库中的多个字段合并为某个类的一部分属性
Annotation中包含<script> 和 <where>等
import java.util.List; import org.apache.ibatis.annotations.Insert; import org.apache.ibatis.annotations.Mapper; import org.apache.ibatis.annotations.Param; import org.apache.ibatis.annotations.ResultMap; import org.apache.ibatis.annotations.Select;@Mapper public interface ScheduleMapper {@Select({"<script>","SELECT * from SCHEDULE"," <where> "," <if test='startDate != null'> START_DATE >= #{startDate} </if>"," <if test='endDate != null'> AND #{endDate} >= END_DATE </if>"," </where> ","</script>"})@ResultMap("scheduleResult")public List<Schedule> listSchedules(@Param("startDate") Date startDate, @Param("endDate") Date endDate);@Select({"<script>", selectSql, " WHERE ID= #{id}", "</script>"})@ResultMap("scheduleResult")public Schedule getSchedule(String id);/*** reference to https://mybatis.org/mybatis-3/dynamic-sql.html*/@Insert({"<script> INSERT INTO DS_SCHEDULE(ID, RECURRENCE_TYPE,WEEK_DAYS) VALUES (#{id}, "+ " <if test='recurrence != null'>"+ " #{recurrence.type}, #{recurrence.weekDays,typeHandler=io.castera.datacastScheduler.mapper.StringListTypeHandler}"+ " </if>"+ " <if test='recurrence == null'> null, null</if>"+ " )","</script>"})public int addSchedule(Schedule sch); }
