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mybatis中的关联查询
1》在实体映射层中引入关联对象
package com.jinglin.hotelsup.model; import java.io.Serializable; public class Goodsinfo implements Serializable{ private Integer goodsid; private Integer companyid; private Integer goodstypeid; private Integer unitid; private String createuser; private String updateuser; private String commdityid; private String commdityname; private String describeit; private String createtime; private String updatetime; private String remark; private String ifdelete; //关联查询 private Unit unit; private Goodstype goodstype; private Company company; public Unit getUnit() { return unit; } public void setUnit(Unit unit) { this.unit = unit; } public Goodstype getGoodstype() { return goodstype; } public void setGoodstype(Goodstype goodstype) { this.goodstype = goodstype; } public Company getCompany() { return company; } public void setCompany(Company company) { this.company = company; } public Integer getGoodsid() { return goodsid; } public void setGoodsid(Integer goodsid) { this.goodsid = goodsid; } public Integer getCompanyid() { return companyid; } public void setCompanyid(Integer companyid) { this.companyid = companyid; } public Integer getGoodstypeid() { return goodstypeid; } public void setGoodstypeid(Integer goodstypeid) { this.goodstypeid = goodstypeid; } public Integer getUnitid() { return unitid; } public void setUnitid(Integer unitid) { this.unitid = unitid; } public String getCreateuser() { return createuser; } public void setCreateuser(String createuser) { this.createuser = createuser; } public String getUpdateuser() { return updateuser; } public void setUpdateuser(String updateuser) { this.updateuser = updateuser; } public String getCommdityid() { return commdityid; } public void setCommdityid(String commdityid) { this.commdityid = commdityid; } public String getCommdityname() { return commdityname; } public void setCommdityname(String commdityname) { this.commdityname = commdityname; } public String getDescribeit() { return describeit; } public void setDescribeit(String describeit) { this.describeit = describeit; } public String getCreatetime() { return createtime; } public void setCreatetime(String createtime) { this.createtime = createtime; } public String getUpdatetime() { return updatetime; } public void setUpdatetime(String updatetime) { this.updatetime = updatetime; } public String getRemark() { return remark; } public void setRemark(String remark) { this.remark = remark; } public String getIfdelete() { return ifdelete; } public void setIfdelete(String ifdelete) { this.ifdelete = ifdelete; } }
2》在同目录下的GoodsinfoMapper下配置查询结果集
3》编写关联查询语句
<?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.jinglin.hotelsup.dao.imp.GoodsinfoMapper"> <!-- 表示关联表的查询 --> <sql id="getsql"> select t.* from (Select rownum as rn,gs.*, gp.goodstypename, c.companyname,c.address, u.code From goodsinfo gs inner join goodstype gp on gs.goodstypeid = gp.goodstypeid inner join company c on gs.companyid = c.companyid inner join unit u on gs.unitid = u.unitid where gs.ifdelete=‘N‘)t </sql> <select id="getmodel" resultMap="goodsinfo"> <include refid="getsql"></include> where t.ifdelete=‘N‘ and t.goodsid=#{id} </select> <!-- 配置结果集 --> <resultMap type="Goodsinfo" id="goodsinfo"> <!-- 配置主键 --> <id column="goodsid" property="goodsid"></id> <result column="goodstypeid" property="goodstypeid"></result> <result column="companyid " property="companyid "></result> <result column="unitid" property="unitid"></result> <result column="createuser" property="createuser"></result> <result column="updateuser" property="updateuser"></result> <result column=" commdityid" property="commdityid"></result> <result column="commdityname" property="commdityname"></result> <result column="describeit" property="describeit"></result> <result column="createtime" property="createtime"></result> <result column="updatetime" property="updatetime"></result> <result column="remark" property="remark"></result> <result column="ifdelete" property="ifdelete"></result> <!-- 配置关联实体数据 --> <association property="goodstype" javaType="Goodstype"> <id property="goodstypeid" column="goodstypeid"></id> <result property="goodstypename" column="goodstypename"/> <result property="ifdel" column="ifdel"/> </association> <association property="company" javaType="Company"> <id column="companyid" property="companyid"></id> <result column="companyname" property="companyname"/> <result column="address" property="address"/> <result column="ifdel" property="ifdel"></result> </association> <association property="unit" javaType="Unit"> <id column="unitid" property="unitid"/> <result column="code" property="code"/> <result column="ifdel" property="ifdel"/> </association> </resultMap> <!-- 查询所有的数据 --> <select id="getlist" resultMap="goodsinfo"> <include refid="getsql"></include> where t.ifdelete=‘N‘ </select> <!-- 查询带分页和查询条件的 --> <select id="getgoodslistbypage" resultMap="goodsinfo"> <include refid="getsql"></include> where t.ifdelete=‘N‘ <if test="goodsinfo.goodsid!=null"> and t.goodsid=#{goodsInfo.goodsid} </if> <if test="goodsinfo.commdityname!=null and goodsinfo.commdityname!=‘‘"> and t.commdityname like ‘%${goodsInfo.commdityname}%‘ </if> <!-- 查询时间 --> <if test="goodsinfo.createtime!=null and goodsinfo.createtime!=‘‘"> and t.createtime like ‘%${goodsInfo.createtime}%‘ </if> <![CDATA[ and t.rn>=#{startindex} and t.rn<=#{endindex} ]]> </select> <!-- 数据的插入操作 --> <insert id="additem" useGeneratedKeys="true" keyColumn="goodsid" keyProperty="goodsid" parameterType="GoodsInfo"> insert into goodsinfo(goodsid,companyid,goodstypeid,unitid, createuser,updateuser,commdityid, commdityname,describeit,createtime, updatetime,remark) values(userseq.nextval,#{companyid},#{goodstypeid},#{unitid}, #{createuser},#{updateuser},#{commdityid}, #{commdityname},#{describeit},#{createtime}, #{updatetime},#{remark}) </insert> <!-- 数据的删除 --> <update id="deleteitem"> update goodsinfo set ifdelete=‘Y‘ where goodsid=#{id} </update> <!-- 数据的更新 --> <update id="updateitem" parameterType="Goodsinfo"> update goodsinfo <set> <if test="companyid!=null"> companyid=#{companyid}, </if> <if test="goodstypeid!=null"> goodstypeid=#{goodstypeid}, </if> <if test="unitid!=null"> unitid=#{unitid}, </if> <if test="createuser!=null"> createuser=#{createuser}, </if> <if test="updateuser!=null"> updateuser=#{updateuser}, </if> <if test="commdityid!=null"> commdityid=#{commdityid}, </if> <if test="commdityname!=null"> commdityname=#{commdityname}, </if> <if test="describeit!=null"> describeit=#{describeit}, </if> <if test="createtime!=null"> createtime=#{createtime}, </if> <if test="updatetime!=null"> updatetime=#{updatetime}, </if> <if test="remark!=null"> remark=#{remark}, </if> <if test="ifdelete!=null"> ifdelete=#{ifdelete} </if> </set> where goodsid=#{goodsid} </update> </mapper>
ps:rownum as rn是为了做分页查询
<![CDATA[
and t.rn>=#{startindex}
and t.rn<=#{endindex}
]]>
第一行代码和第四行是为了向程序解释>=和<=是逻辑表达式而不是标签
此为多对一的查询,若一对多,则配置结果集的标签为
<collection property="" ofType=""></collection>
mybatis中的关联查询
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