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How to use MyBatis to easily achieve recursive query and stored procedure calls, I believe that many inexperienced people do not know what to do. Therefore, this paper summarizes the causes and solutions of the problem. Through this article, I hope you can solve this problem.

Recursive call

Because the level of the department is not controllable, if I want to get the complete json of all departments, I have to use recursive calls and use Java code to deal with recursive low. It just so happens that the collection in the ResultMap of MyBatis can easily solve this problem. The core code is as follows:

Select d1.*from department D1 where d1.`parentId` = # {pid} AND d1.enabled=true

Each Department has a children property, and the return result of the getDepByPid method is a collection in BaseResultMap,BaseResultMap and the getDepByPid method will be called, so we can quickly implement a recursive call. You only need to define the following methods in Mapper:

List getDepByPid (Long pid)

The query results are as follows (part):

[{"id": 1, "name": "shareholders' meeting", "parentId":-1, "enabled": true, "children": [{"id": 4, "name": "Chairman", "parentId": 1, "enabled": true "children": [{"id": 5, "name": "General Manager", "parentId": 4, "enabled": true "children": [{"id": 8, "name": "Finance Department", "parentId": 5, "enabled": true "children": [], "parent": false}], "parent": true}], "parent": true}] "parent": true}] stored procedure call

It is relatively simple to call a stored procedure. Take adding a department as an example, as follows:

Add the following methods to 1.Mapper:

Void addDep (@ Param ("dep") Department department)

It is written as follows in 2.xml:

Call addDep (# {dep.name,mode=IN,jdbcType=VARCHAR}, # {dep.parentId,mode=IN,jdbcType=INTEGER}, # {dep.enabled,mode=IN,jdbcType=BOOLEAN}, # {dep.result,mode=OUT,jdbcType=INTEGER}, # {dep.id,mode=OUT,jdbcType=BIGINT})

Note that the statementType call indicates that this is a stored procedure, mode=IN indicates that this is the input parameter, and mode=OUT indicates that this is the output parameter. After a successful call, get the id and result fields of department in service, and you can get the corresponding call result.

After reading the above, have you mastered how to easily implement recursive queries and stored procedure calls using MyBatis? If you want to learn more skills or want to know more about it, you are welcome to follow the industry information channel, thank you for reading!

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