Mybatis results generate key-value pairs-javaTutorial-php.cn

Mybatis results generate key-value pairs

高洛峰

Release： 2017-02-27 16:21:19

Original

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The following is an example code for generating key-value pairs from mybatis results. The specific content is as follows:

In practical applications, we often encounter such situations and need to provide drop-down boxes. Assignment, this time you need a key-value pair. The specific usage method is as follows

1. Define the result type (resultType) in the maper.xml file as hashmap, as shown below

<select id="selectSuperUnitInfo" resultType="hashmap">
  SELECT unit_id ,unit_name from unit_info
 </select>

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##2, use List> in the corresponding mapper class to accept this type, as shown below

public List<Map<String,String>> selectSuperUnitInfo();

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In fact, the most powerful one is the resultMap type. This can be customized in the mapper.xml file and then added to the package. That’s it, it’s really powerful

Let me add that MyBatis returns Map key-value pair data

List<Map<String, String>> getMtypeList();
<select id="getMtypeList" resultType="java.util.HashMap">
  select code,`name` from jk_control_measure
</select>

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[DEBUG] 2016-08-29 17:50:09 :==> Executing: select code,`name` from jk_control_measure 
[DEBUG] 2016-08-29 17:50:09 :==> Parameters: 
[DEBUG] 2016-08-29 17:50:10 :<==  Columns: code, name
[DEBUG] 2016-08-29 17:50:10 :<==    Row: one, 地面冲洗
[DEBUG] 2016-08-29 17:50:10 :<==    Row: two, 边界围挡
[DEBUG] 2016-08-29 17:50:10 :<==    Row: three, 垃圾覆盖
[DEBUG] 2016-08-29 17:50:10 :<==    Row: four, 裸地覆盖
[DEBUG] 2016-08-29 17:50:10 :<==    Row: five, 洒水降尘
[DEBUG] 2016-08-29 17:50:10 :<==    Row: six, 车辆冲洗
[DEBUG] 2016-08-29 17:50:10 :<==    Row: seven, 建筑渣土
[DEBUG] 2016-08-29 17:50:10 :<==    Row: eight, 车辆冒装
[DEBUG] 2016-08-29 17:50:10 :<==    Row: nine, 扬尘覆盖
[DEBUG] 2016-08-29 17:50:10 :<==    Row: ten, 车辆撒漏
[DEBUG] 2016-08-29 17:50:10 :<==    Row: eleven, 车辆黑烟
[DEBUG] 2016-08-29 17:50:10 :<==    Row: twelve, 道路积尘

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[{"NAME":"地面冲洗","name":"地面冲洗","code":"one","CODE":"one"},
{"NAME":"边界围挡","name":"边界围挡","code":"two","CODE":"two"},
{"NAME":"垃圾覆盖","name":"垃圾覆盖","code":"three","CODE":"three"},
{"NAME":"裸地覆盖","name":"裸地覆盖","code":"four","CODE":"four"},
{"NAME":"洒水降尘","name":"洒水降尘","code":"five","CODE":"five"},
{"NAME":"车辆冲洗","name":"车辆冲洗","code":"six","CODE":"six"},
{"NAME":"建筑渣土","name":"建筑渣土","code":"seven","CODE":"seven"},
{"NAME":"车辆冒装","name":"车辆冒装","code":"eight","CODE":"eight"},
{"NAME":"扬尘覆盖","name":"扬尘覆盖","code":"nine","CODE":"nine"},
{"NAME":"车辆撒漏","name":"车辆撒漏","code":"ten","CODE":"ten"},
{"NAME":"车辆黑烟","name":"车辆黑烟","code":"eleven","CODE":"eleven"},
{"NAME":"道路积尘","name":"道路积尘","code":"twelve","CODE":"twelve"}
]

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The returned result contains uppercase and lowercase keys

If in the sql statement What will happen if the column names in are uppercase? Test it yourself! If you have any questions, please leave me a message and I will reply to you in time. I would also like to thank you all for your support of the PHP Chinese website!

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