mapper.xml 中共用
mapper.xml 間共用
項目中也許我們會遇到一段sql語句被多個查詢、增加等語句用到的情況，如何去偷懶呢，復用sql無疑是較好的選擇
這里只提供簡單的示范：
如果只是單表查詢，并且希望共用的sql只會出現在同一個mapper.xml文件中，那么我們可以直接在
|
1
|
<mapper namespace="XXXXX"></mapper> |
中寫下面的業務代碼
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
|
<sql id="unitSql"> a.userId,a.legalCode,legalName, bidderCodeType,legalRole, licenseNo,DATE_FORMAT(licenseEndDate,"%Y-%m-%d") AS licenseEndDate, taxCertNo,DATE_FORMAT(taxCertEndDate,"%Y-%m-%d") AS taxCertEndDate, localTaxCertNo,DATE_FORMAT(localTaxCertEndDate,"%Y-%m-%d") AS localTaxCertEndDate, organNo,DATE_FORMAT(organCertEndDate,"%Y-%m-%d") AS organCertEndDate, legalRepresent,legalType, perresentPhone,legalIndustary,creditRate, countryRegion,legalUnitAddress,regionCode,registerProvince, a.regCapital,a.regCapCurRency,a.regUnit, registerCity,registerCounty,basicBank,basicBranchBank, basicAccountNo,basicAccountName,legalContact,legalContactPhone, legalContactAddress,legalWeb,legalZipCode,legalEmail, legalStatus</sql> |
然后引用
|
1
2
3
4
5
6
7
8
9
10
|
<select id="getTenderAgentById" parameterType="String" resultType="Map"> select <include refid="unitSql"/>, -- 就是這句話引用 ，refid為共有sql語句id b.auditOpinion,b.createUser, b.createTime, b.lastUpdateUser, b.lastUpdateTime, b.disabled,b.infoStatus from P_legalUnit a, P_tenderAgent b where b.userId=#{userId} AND a.userId = b.userId AND b.disabled='0'</select> |
如果是連表查詢，那么我們極有可能會希望有一個sql語句被多個mapper.xml引用的的方法，很簡單。
我們可以新建一個mapper.xml文件（當然，這個mapper.xml要在你的掃描路徑下，本文不贅述）。取名為common.xml
該文件內容為
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
|
<?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="common"> <sql id="common.unitSql"> a.userId,a.legalCode,legalName, bidderCodeType,legalRole, licenseNo,DATE_FORMAT(licenseEndDate,"%Y-%m-%d") AS licenseEndDate, taxCertNo,DATE_FORMAT(taxCertEndDate,"%Y-%m-%d") AS taxCertEndDate, localTaxCertNo,DATE_FORMAT(localTaxCertEndDate,"%Y-%m-%d") AS localTaxCertEndDate, organNo,DATE_FORMAT(organCertEndDate,"%Y-%m-%d") AS organCertEndDate, legalRepresent,legalType, perresentPhone,legalIndustary,creditRate, countryRegion,legalUnitAddress,regionCode,registerProvince, a.regCapital,a.regCapCurRency,a.regUnit, registerCity,registerCounty,basicBank,basicBranchBank, basicAccountNo,basicAccountName,legalContact,legalContactPhone, legalContactAddress,legalWeb,legalZipCode,legalEmail, legalStatus </sql></mappper> |
在另一個mapper.xml文件引用
|
1
2
3
4
5
6
7
8
9
10
|
<select id="getTenderAgentById" parameterType="String" resultType="Map"> select <include refid="common.unitSql"/>, -- 就是這句話引用 ，refid為共有sql語句id b.auditOpinion,b.createUser, b.createTime, b.lastUpdateUser, b.lastUpdateTime, b.disabled,b.infoStatus from P_legalUnit a, P_tenderAgent b where b.userId=#{userId} AND a.userId = b.userId AND b.disabled='0'</select> |
==注:為何我的文件名要取為common.xml并且id也為common.unitSql呢？這是為了后期維護方便，如此，可以更容易找到該共有的sql在哪一個文件==
以上所述是小編給大家介紹的Mybatis中 SQL語句復用，希望對大家有所幫助，如果大家有任何疑問請給我留言，小編會及時回復大家的。在此也非常感謝大家對服務器之家網站的支持！
原文鏈接：http://blog.csdn.net/sinat_33155679/article/details/61914139
