Example of Map mode for MyBatis multi-parameter transfer -- thirteen MyBatis Study Notes

The previous article introduced the methods of MyBatis multi-parameter passing annotation and default parameter naming. Today we will introduce the Map method. Still previous paging Method for querying instructor information findTeacherByPage example source code: http://down.51cto.com/data/546809 ).

First, modify the findTeacherByPage method in the ER interface TeacherMapper as follows:

 
 

  
  
// Query the instructor information by PAGE
  
  
Public List <Teacher> findTeacherByPage (Map <String, Object> map );
 
 

Correspondingly, the Map interface should be introduced here: import java. util. Map.

In the execution class CollectionDemo, the code for calling the findTeacherByPage method is as follows:

 
 

  
  
Map <String, Object> params =
  
  
New HashMap <String, Object> ();
  
  
// Sort by name in ascending order,
  
  
Params. put ("sort", "name ");
  
  
Params. put ("dir", "asc ");
  
  
// The query results start from 0th and query 2 records
  
  
Params. put ("start", 0 );
  
  
Params. put ("limit", 2 );
  
  
// Query the instructors whose titles are professors or associate professors
  
  
Params. put ("title", "% professor ");
  
  
// Query the instructor information by PAGE
  
  
List <Teacher> teachers =
  
  
Mapper. findTeacherByPage (params );
 
 

We can see that we put the parameter in a Map first, so that we can use # {…} in the corresponding SQL statement #{...} These parameters are referenced. As follows:

 
 

  
  
<selectid="findTeacherByPage"resultMap="supervisorResultMap"
  
  
parameterType="java.util.Map">
  
  
              select * from teacher where title like #{title}           
  
  
              order by ${sort} ${dir} limit #{start},#{limit}  
  
  
</select>
 
 

As before, $ {…} should be used in the order by clause {...} . In fact, parameterType = "java. util. Map" here can be avoided.

The running result is as follows:

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MyBatis Study Notes series I: download and install ant

Prepare for MyBatis Study Notes Series II: ant getting started

MyBatis learning notes: MyBatis getting started

MyBatis Study Notes Series II: Example of adding, deleting, and modifying MyBatis

MyBatis Study Notes Series 3: association examples of MyBatis

MyBatis Study Notes Series 4: two forms of MyBatis association

MyBatis Study Notes Series 5: examples of integration between MyBatis and Spring

MyBatis Study Notes Series 6: examples of integration between MyBatis and Spring

MyBatis study notes 7: MyBatis one-to-multiple bidirectional Association

MyBatis Study Notes: MyBatis MapperScannerConfigurer Configuration

MyBatis Study Notes: two forms of MyBatis collection

MyBatis Study Notes Series 10: Log4j example of MyBatis logs

MyBatis Study Notes: example of how to annotate MyBatis with multiple parameters

MyBatis learning notes: Example of the default naming method for MyBatis multi-parameter transfer

MyBatis Study Notes: Example of Map mode for MyBatis multi-parameter transfer

MyBatis Study Notes: N + 1 in MyBatis

MyBatis Study Notes: a hybrid transfer of multiple parameters in MyBatis

MyBatis Study Notes:Spring declarative Transaction Management example

MyBatis Study Notes: Example of MyBatis multiple-to-multiple storage

This article is from the "Xiao fan's column" blog, please be sure to keep this source http://legend2011.blog.51cto.com/3018495/1030804