CODEWITHSUNDEEP
javamybatismapper
RjnshD
RjnshD

Reputation: 11

Mybatis mapping for select * query

I was trying to write a mybatis mapper for a select * query which would return me a list of rows from a ProcessType table. And each row has to be mapped to a ProcessType pojo. I know how to map a single row to the POJO, but how to go about this for list of Process Type?

POJO--> class name : ProcessType Properties:
String ABC; String id; String Date;

From mapper I call a proc 'XYZ' which returns me the cursor for list of rows for ProcessType table being queried.

Upvotes: 1

Views: 25251

Answers (5)

Russ
Russ

Reputation: 2006

Assuming you've used the mybatis javaModelGenerator, sqlMapGenerator, and javaClientGenerator, all you would need to do is to use the .selectByExample() function in your mapper class and feed in an "empty" Example object such as the following:

for (MyTable myTable : myTableMapper.selectByExample(new MyTableExample())) {
    System.out.println("found ID: " + myTable.getId());
}

This is equivalent to a select *

Upvotes: 1

Sky
Sky

Reputation: 7691

All you need to do is define a resultMap like this:

<resultMap id="processTypeMap" type="yourpackage.ProcessType">
    <id property="id" column="id_in_db"/>
    <result property="abc"         column="abc_in_db"/>
    <result property="date"     column="date_in_db"/>
</resultMap>

The column is the associated field in your table mapping.

Then set resultMap as what you defined above like this:

<select id="getProcessTypes" resultMap="processTypeMap">
    select * from ProcessType
</select>

Now the columns in your table will be mapped accordingly.

I suppose that you want to get a list of ProcessType, so in the DAO layer, you have to use the selectList method.

List<ProcessType> processTypes = sqlSessionTemplate.selectList("getProcessTypes")

Upvotes: 1

garlicbread
garlicbread

Reputation: 25

If I understand this correctly are you using a collection in your result map? this tells mybatis to expect a list.

<collect property="" column="">

Upvotes: 0

Pau
Pau

Reputation: 16086

I don't understand well at all the question. Primary, I think it is not needed a procedure for this simple operation, I would do it as a simple query.

So, If you have this entity.

    public class ProcessType {

    String ABC, id, Date;

    public ProcessType(String aBC, String id, String date) {
        ABC = aBC;
        this.id = id;
        Date = date;
    }

    public String getABC() {
        return ABC;
    }

    public void setABC(String aBC) {
        ABC = aBC;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getDate() {
        return Date;
    }

    public void setDate(String date) {
        Date = date;
    }

}

And a table ProcessType as something like this:

create table PROCESS_TYPE (
   ABC VARCHAR(200),
   ID  VARCHAR(200),
   DATE VARCHAR(200)
);

Your mapper using annotations should be as follows:

public interface MapperProcessType {

@Select("select * from PROCESS_TYPE")
@Results({
    @Result(property = "ABC", column = "ABC"),
    @Result(property = "id", column = "ID"),
    @Result(property = "date", column = "DATE")
  })
public List<ProcessType> findAll();

}

On other hand, using xml It is as the next:

<resultMap id = "result" type = "ProcessType">
   <result property = "ABC" column = "ABC"/>
   <result property = "id" column = "ID"/>
   <result property = "date" column = "DATE"/>
</resultMap>

<select id = "findAll" resultMap = "result">
   SELECT * FROM PROCESS_TYPE
</select>

Upvotes: 5

Troncoso
Troncoso

Reputation: 2463

Your Mapper.java class just needs to return a list:

List<ProcessType> getProcessTypes();

Your Mapper.xml should use the class as the resultType:

<select id="getProcessTypes" resultType="path.to.ProcessType">

Or you can create a result map to map your columns to the ProcessType properties, but that's outside the scope of this question.

Upvotes: 1

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