問題描述:
最近項目中,發現一個問題,項目框架是springmvc+mybatis;
我需要根據 Id 用 in 條件來查詢數據,一開始我在後臺將條件都按照逗號拼接好,然後存儲爲字符串形式:
例如:String id = {'1', '2', '3', '4'};
將變量id傳遞到mybatis中,但是發現並沒有什麼用,然後用list也不行;
解決方案:
將Id集合存儲到Map中,例如:
Map<String, Object> params = new HashMap<String, Object>();
String[] ids = {"1","2","3","4"};
List<String> idsList = new ArrayList<String>();
// 存儲id
for(String id : ids) {
idsList.add(id);
}
params.put("idsList", idsList);
Mybatis中
<select id="getList" resultMap="BaseResultMap" parameterType="map">
select * from baseDistWaterPlan dwp
where 1=1
<if test="idsList != null and idsList.size()>0">
and dwp.WaterAreaId in
<foreach collection="idsList" item="item" index="index" open="(" separator="," close=")">
#{item}
</foreach>
</if>
</select>
即可達到in的處理效果。