MyBatis(十一)：Mybatis 动态SQL语句完成多条件查询

之前文章中对in的用法做过讲解：《MyBatis(四)：mybatis中使用in查询时的注意事项》

实际上对于多个参数的用法也是这是注意的：

多参&if判空&List集合判空&in用法

    @Options(useCache = true, flushCache = Options.FlushCachePolicy.FALSE, timeout = 60000)
    @Select(value = {
            "<script>",
            " SELECT  `id`,`title` ",
            " FROM `tb_article` ",
            " WHERE `category_id`=#{article.categoryId} ",
            "   <if test='article.status!=null'>",
            "   AND `status` = #{article.status} ",
            "   </if>",
            "   <if test='typeList!=null and !typeList.isEmpty()'>",
            "       and `article_type` in",
            "        <foreach collection=\"typeList\" index=\"index\" item=\"item\" open=\"(\" separator=\",\" close=\")\">",
            "           #{item} ",
            "        </foreach>",
            "   </if>",
            "</script>"
            })
    @ResultMap(value = {"articleResultMap"})
    List<ArticlePo> queryByCondition(final @Param("article") ArticleModel article, final @Param("typeList") List<Integer> typeList);

1）上边主要对普通参数判断空用法：<if test='article.status!=null'>

2）集合判空的用法：<if test='typeList!=null and !typeList.isEmpty()'>

3）in的用法：<foreach collection=\"typeList\" index=\"index\" item=\"item\" open=\"(\" separator=\",\" close=\")\">"；

4）多参数用法，实际上多个参数如果使用@SqlProvider方式是，在ArticleSqlProvider的类中方法中接收的参数对象为Map<String,Object>,该map集合中包含两个对象：key:article的ArticleModel对象；key:typeList的List<Integer>对象。获取方式：ArticleModel aritlce=(ArticleModel)map.get("aritcle");List<Integer> typeList=(List<Integer>)map.get("typeList");。

Mybatis使用POJO传递参数：

        @Options(useCache = true, flushCache = Options.FlushCachePolicy.FALSE, timeout = 60000)
        @ResultMap("logResult")
        @Select(value={ 
                "<script>",
                "select * from `log` " ,
                "<where>" ,
                "     <if test=\"title!=null and title!=''\">" ,
                "          and `title` like CONCAT('%', #{title}, '%') " , 
                "     </if>" ,
                "     <if test=\"moduleType!=null \">" , 
                "          and `module_type`=#{moduleType} " , 
                "     </if>" , 
                "     <if test=\"operateType!=null \">" , 
                "          and `operate_type`=#{operateType} " , 
                "     </if>" , 
                "</where>",
                "</script>"
                })
        List<Log> getByPojo(Log log);

src/main/resources/mybatis-config.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <!-- 引用db.properties配置文件 -->
    <properties resource="jdbc.properties"/>
    <!--配置全局属性-->
    <settings>
        <!-- 打开延迟加载的开关 -->
        <setting name="lazyLoadingEnabled" value="true"/>
        <!-- 将积极加载改为消极加载（即按需加载） -->
        <setting name="aggressiveLazyLoading" value="false"/>
        <!-- 打开全局缓存开关（二级缓存）默认值就是 true -->
        <setting name="cacheEnabled" value="true"/>
        <!--使用jdbc的getGeneratekeys获取自增主键值-->
        <setting name="useGeneratedKeys" value="true"/>
        <!--使用列别名替换别名　　默认true select name as title form table; -->
        <setting name="useColumnLabel" value="true"/>
        <!--开启驼峰命名转换-->
        <setting name="mapUnderscoreToCamelCase" value="true"/>
        <!--打印sql日志-->
        <setting name="logImpl" value="STDOUT_LOGGING" />
    </settings>
    <typeAliases>
        <package name="com.dx.test.model"/>
    </typeAliases>
    <!-- 
　　　　元素类型为 "configuration" 的内容必须匹配 "
　　　　(properties?,settings?,typeAliases?,typeHandlers?,objectFactory?,objectWrapperFactory?,reflectorFactory?,
　　　　　　plugins?,environments?,databaseIdProvider?,mappers?)"。
　　 -->
    <typeHandlers>
        <typeHandler handler="org.apache.ibatis.type.EnumOrdinalTypeHandler" javaType="com.dx.test.model.enums.ModuleType"/>
        <typeHandler handler="org.apache.ibatis.type.EnumOrdinalTypeHandler" javaType="com.dx.test.model.enums.OperateType"/>
    </typeHandlers>
    <!-- 对事务的管理和连接池的配置 -->
    <environments default="mysql_jdbc">
        <environment id="mysql_jdbc">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="${driver}"/>
                <property name="url" value="${url}"/>
                <property name="username" value="${name}"/>
                <property name="password" value="${password}"/>
            </dataSource>
        </environment>
    </environments>
    <!--
    <mappers>
        <mapper resource="resources/mapper/LogMapper.xml"/>
    </mappers>
    -->
    <mappers>
        <mapper class="com.dx.test.dao.LogMapper"></mapper>
    </mappers>
</configuration>

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