Mybatis傳遞多個參數(shù)進行SQL查詢的用法
PS:ibatis3如何傳遞多個參數(shù)有兩個方法:一種是使用java.Map,另一種是使用JavaBean。
當只向xxxMapper.xml文件中傳遞一個參數(shù)時,可以簡單的用“_parameter”來接收xxxMapper.java傳遞進來的參數(shù),并代入查詢,比如說這樣:
(1)xxxMapper.java文件中這樣定義:
List<String> selectAllAirportCode(Boolean mapping);
(2)這時在對應(yīng)的xxxMapper.xml文件中可以使用“_parameter”來接收這個參數(shù):
<select id="selectAllAirportCode" resultType="java.lang.String" parameterType="java.lang.Boolean"> select DEPARTURE_AIRPORT from USR_AIR_LINE union select ARRIVAL_AIRPORT from USR_AIR_LINE <if test="_parameter == true"> union select REL_DEPARTURE_AIRPORT from USR_AIR_LINE union select REL_ARRIVAL_AIRPORT from USR_AIR_LINE </if> </select>
但是,如果在xxxMapper.java文件中傳遞進來多個參數(shù),就不能使用上面這種形式來接收參數(shù),這時可以有兩種方案來解決這個問題:
一 向xml文件中傳遞進去一個Map<String, Object>集合,然后xml文件中就可以正常使用Map集合中的各個參數(shù)了。
具體實例如下:
(1)xxxMapper.java文件中這樣定義:
List<Airline> findAll(Map<String, Object> parms);
(2)在用到上面定義的具體實現(xiàn)類中給Map傳參:
public List<Airline> findAll(PageInfo page,Airline airline) { HashMap<String,Object> params = new HashMap<String,Object>(); params.put("page", page); params.put("airline", airline); return airlineMapper.findAll(params); }
(3)此時對應(yīng)的xxxMapper.xml文件使用“java.util.Map”來接收這個Map集合:
<sql id="sqlfileders"> <bind name="fileders" value="#{'id':'ID','departureAirport':'DEPARTURE_AIRPORT','relDepartureAirport':'REL_DEPARTURE_AIRPORT','arrivalAirport':'ARRIVAL_AIRPORT','relArrivalAirport':'REL_ARRIVAL_AIRPORT','popStatus':'POP_STATUS','status':'STATUS','creator':'CREATOR','createTime':'CREATE_TIME'}" /> <bind name="javapropertys" value="#{'ID':'id','DEPARTURE_AIRPORT':'departureAirport','REL_DEPARTURE_AIRPORT':'relDepartureAirport','ARRIVAL_AIRPORT':'arrivalAirport','REL_ARRIVAL_AIRPORT':'relArrivalAirport','POP_STATUS':'popStatus','STATUS':'status','CREATOR':'creator','CREATE_TIME':'createTime'}" /> </sql> <select id="findAll" resultMap="BaseResultMap" parameterType="java.util.Map"> <![CDATA[ select x.* from ( select z.*, rownum numbers from ( ]]> select <include refid="Base_Column_List" /> from USR_AIR_LINE <where> <if test="airline.departureAirport != null"> DEPARTURE_AIRPORT = #{airline.departureAirport} </if> <if test="airline.arrivalAirport != null"> and ARRIVAL_AIRPORT=#{airline.arrivalAirport} </if> <if test="airline.relDepartureAirport != null"> and REL_DEPARTURE_AIRPORT = #{airline.relDepartureAirport} </if> <if test="airline.relArrivalAirport != null"> and REL_ARRIVAL_AIRPORT = #{airline.relArrivalAirport} </if> <if test="airline.popStatus != null"> and POP_STATUS = #{airline.popStatus} </if> <if test="airline.status != null"> and STATUS = #{airline.status} </if> </where> <if test="page.sortName != null"> <include refid="sqlfileders" /> <bind name="orderfield" value="#this.fileders[page.sortName]" /> order by ${orderfield} ${page.sortOrder} </if> <![CDATA[ ) z where rownum < ]]> #{page.to} <![CDATA[ ) x where x.numbers >= ]]> #{page.from} </select>
注:上面的實例實現(xiàn)的是分頁查詢數(shù)據(jù)。我們可以發(fā)現(xiàn)使用Map來傳遞參數(shù)這種形式并不好,因為這樣使得在接口中只有一個Map參數(shù),其他人進行維護的時候并不清楚到底需要向這個Map里面?zhèn)鬟f什么參數(shù)進去
二 通過給參數(shù)添加@Param注解來解決問題:
(1)給xxxMapper.java文件的方法中的參數(shù)添加@Param注解,這個注解中的值對應(yīng)xml文件中使用到的參數(shù)名稱:
Airline selectEffectiveAirline( @Param("departureAirport") String departureAirport, @Param("arrivalAirport") String arrivalAirport, @Param("status") BigDecimal status);
(2)此時xxxMapper.xml文件中對應(yīng)的地方就可以正常使用在@Param注解中對應(yīng)的值了:
<select id="selectEffectiveAirline" resultMap="BaseResultMap" parameterType="java.util.Map"> select <include refid="Base_Column_List" /> from USR_AIR_LINE <where> <if test="departureAirport != null"> DEPARTURE_AIRPORT = #{departureAirport} </if> <if test="arrivalAirport != null"> and ARRIVAL_AIRPORT=#{arrivalAirport} </if> <if test="status != null"> and STATUS = #{status} </if> </where> </select>
注:需要注意的是if條件判斷中的參數(shù)和在SQL語句中寫法是不一樣的,if判斷中的變量是沒有添加#{ }的
下面在單獨給大家介紹下通過Mybatis傳遞多個參數(shù)的兩個方法
Map傳遞多個參數(shù)
parameterType 可以是別名或完全限定名,map或者java.util.Map,這兩個都是可以的
<select id="selectBlogByMap" parameterType="map" resultType="Blog"> select t.ID, t.title, t.content FROM blog t where t.title = #{h_title} and t.content =#{h_content} </select> public void testSelectByMap() { SqlSession session = sqlSessionFactory.openSession(); Map<String, Object> param=new HashMap<String, Object>(); param.put("h_title", "oracle"); param.put("h_content", "使用序列"); Blog blog = (Blog)session.selectOne("cn.enjoylife.BlogMapper.selectBlogByMap",param); session.close(); System.out.println("blog title:"+blog.getTitle()); }
通過JavaBean傳遞多個參數(shù)
<select id="selectBlogByBean" parameterType="Blog" resultType="Blog"> select t.ID, t.title, t.content from blog t wheret.title = #{title} and t.content =#{content} </select> public void testSelectByBean() { SqlSession session = sqlSessionFactory.openSession(); Blog blog=new Blog(); blog.setTitle("oracle"); blog.setContent("使用序列!"); Blog newBlog = (Blog)session.selectOne("cn.enjoylife.BlogMapper.selectBlogByBean",blog); session.close(); System.out.println("new Blog ID:"+newBlog.getId()); }
相關(guān)文章
Java inputstream和outputstream使用詳解
這篇文章主要介紹了Java inputstream和outputstream使用詳解,本篇文章通過簡要的案例,講解了該項技術(shù)的了解與使用,以下就是詳細內(nèi)容,需要的朋友可以參考下2021-08-08Java中反射的"暴破"機制(SetAccessible方法)詳解
這篇文章主要為大家詳細介紹了Java中反射的"暴破"機制,以及如何利用這一機制實現(xiàn)訪問非公有屬性,方法,和構(gòu)造器,文中示例代碼講解詳細,感興趣的可以了解一下2022-08-08