很多时候mysql的一列当中存的是json格式的数据，这时候如果要查询某个key对应的值的时候要如何查询呢，这里记录一种查询方法：

json列的值：
{“InventoryMainTypeCode”: 1, “InventoryMainTypeName”: “GOOD”}

现在要查询InventoryMainTypeCode为xxx或者InventoryMainTypeName为xxx的数据：（这里以springboot+mybatis为例子）

代码：
请求类：

Query query = new Query();

@Data
public class Query implements Serializable {private Map<String, Object> featureMap = new HashMap<>();public void setFeature(String feature) {if (StringUtils.isNotBlank(feature)) {featureMap = JSON.parseObject(feature, Map.class);}}public void addFeature(String key, Object value) {if (StringUtils.isBlank(key)) {return;}this.featureMap.put(key, value);}public void addFeatureMap(Map<String, Object> featureMaps) {if (MapUtils.isNotEmpty(featureMaps)){this.featureMap.putAll(featureMaps);}}
}

在代码中将key添加到Feature中：

query.addFeature(DicConst.InventoryMainTypeCode.name(), 1);
List<ResultDTO> dTOS = dictionaryManager.queryDicByParam(query);

mapper文件：

 List<CnbDictionaryDO> queryDicByParam(CnbDictionaryQuery query);

xml:

  <select id="queryDicByParam" resultMap="BaseResultMap">select<include refid="Base_Column_List"/>from<include refid="Table_Name"/><where><if test="id != null">and id = #{id}</if><if test="featureMap != null and featureMap.size > 0"><foreach collection="featureMap" index="key" item="value"><if test="value != null"><![CDATA[and feature->'$.${key}' = #{value}]]></if></foreach></if></where></select>