MyBatis中的占位符入参全面详解

// 使用#{}作为参数占位符
MyInfo getMyInfoByNameUseWell(String infoName);
// 使用${}作为参数占位符
MyInfo getMyInfoByNameUseDollar(String infoName);

<select id="getMyInfoByNameUseWell" resultMap="myInfoMap">
    SELECT * FROM myinfo WHERE info_name = #{name}
</select>
<select id="getMyInfoByNameUseDollar" resultMap="myInfoMap">
    SELECT * FROM myinfo WHERE info_name = '${name}'
</select>

// 使用#{}作为参数占位符
MyInfo getMyInfoByNameTypeUseWell(@Param("infoName") String infoName, @Param("infoType") String infoType);
// 使用${}作为参数占位符
MyInfo getMyInfoByNameTypeUseDollar(@Param("infoName") String infoName, @Param("infoType") String infoType);

<select id="getMyInfoByNameTypeUseWell" resultMap="myInfoMap">
    SELECT * FROM myinfo WHERE info_name = #{infoName} AND info_type = #{infoType}
</select>
<select id="getMyInfoByNameTypeUseDollar" resultMap="myInfoMap">
    SELECT * FROM myinfo WHERE info_name = '${infoName}' AND info_type = '${infoType}'
</select>

// 使用#{}作为参数占位符
MyInfo getMyInfoByQueryParamUseWell(QueryParam queryParam);
// 使用${}作为参数占位符
MyInfo getMyInfoByQueryParamUseDollar(QueryParam queryParam);

@Data
public class QueryParam {
    private String infoName;
    private String infoType;
    public QueryParam(String infoName, String infoType) {
        this.infoName = infoName;
        this.infoType = infoType;
    }
}

<select id="getMyInfoByQueryParamUseWell" resultMap="myInfoMap"
        parameterType="com.learn.mybatis.dynamic.entity.QueryParam">
    SELECT * FROM myinfo WHERE info_name = #{infoName} AND info_type = #{infoType}
</select>
<select id="getMyInfoByQueryParamUseDollar" resultMap="myInfoMap"
        parameterType="com.learn.mybatis.dynamic.entity.QueryParam">
    SELECT * FROM myinfo WHERE info_name = '${infoName}' AND info_type = '${infoType}'
</select>

// 使用#{}作为参数占位符
MyInfo getMyInfoByMapUseWell(Map<String, Object> queryParamMap);
// 使用${}作为参数占位符
MyInfo getMyInfoByMapUseDollar(Map<String, Object> queryParamMap);

<select id="getMyInfoByMapUseWell" resultMap="myInfoMap">
    SELECT * FROM myinfo WHERE info_name = #{infoName} AND info_type = #{infoType}
</select>
<select id="getMyInfoByMapUseDollar" resultMap="myInfoMap">
    SELECT * FROM myinfo WHERE info_name = '${infoName}' AND info_type = '${infoType}'
</select>

// 传入表名实现动态创建表
void createMyInfoTable(String tableName);
// 传入表名动态指定被查询的表
MyInfo getMyInfoByNameUseWellDynmic(@Param("tableName") String tableName, @Param("infoName") String infoName);

<update id="createMyInfoTable">
    CREATE TABLE ${tableName} (
        id INT(11) PRIMARY KEY AUTO_INCREMENT,
        info_name VARCHAR(255),
        info_type ENUM('USER', 'HOUSE', 'CAR'),
        info_detail VARCHAR(255),
        info_seq INT(11)
    )
</update>
<select id="getMyInfoByNameUseWellDynmic" resultMap="myInfoMap">
    SELECT * FROM ${tableName} WHERE info_name = #{infoName}
</select>

// 为数据库表创建索引
// 表名，索引名，加索引的列的列名全部动态指定
void createIndex(@Param("tableName") String tableName, 
                 @Param("indexName") String indexName, 
                 @Param("columnNames") List<String> columnNames);
// 对查询结果集进行排序并动态指定排序的列名
List<MyInfo> getMyInfosSorted(String columnName);

<update id="createIndex">
    CREATE INDEX
        ${indexName}
    ON
        ${tableName}
    <foreach collection="columnNames" item="columnName"
                open="(" separator="," close=")">
        ${columnName}
    </foreach>
</update>
<select id="getMyInfosSorted" resultMap="myInfoMap">
    SELECT * FROM myinfo ORDER BY ${columnName} DESC
</select>