Question

Maybe I am missing something obvious, but I cannot get a simple mapped insert statement executing successfully.

Using the following interface

public interface CustomItemMapper 
{
    Integer insert(CustomItem item, @Param("extra") String someparam);
}

and the following XML mapping

  <insert id="insert" useGeneratedKeys="false" parameterType="map" keyProperty="id">
    insert into CustomItem (id, column2, column3, column4, column5, column6)
        values (#{id}, #{field2}, #{field3}, #{field4}, #{field5}, #{extra})
  </insert>

and this code

SqlSessionFactory sqlSessionFactory = (SqlSessionFactory) servletContext.getAttribute("SqlSessionFactory");
SqlSession session = sqlSessionFactory.openSession();
try 
{ 
    CustomItemMapper mapper = session.getMapper(CustomItemMapper.class); 
    mapper.update(item);
    session.commit();
} 
finally 
{ 
    session.close(); 
} 

I get the following debug output:

Checked out connection 368716606 from pool.
ooo Connection Opened
==>  Executing: insert into CustomItem (id, column2, column3, column4, column5, column6) values (?, ?, ?, ?, ?, ?) 
==> Parameters: null, null, null, null, null, actual_value_of_extra(String)
xxx Connection Closed
Returned connection 368716606 to pool.

followed by the SQL exception (cannot enter null into the id column).

So the only value that was passed in properly is the extra supplied string. I have verified that the field names are correct and object is not null at this point and the fields are populated properly.

I also tried using parameterType="CustomItem" instead of parameterType="map" but the result did not change.

I would appreciate if someone could let me know what I am missing here.

Thanks in advance.

PS: I get into the same problem with insert statements, as well.

Answer 1

You need to specify the name of the other parameter in your mapper method. I’m assuming CustomItem is a Java bean, with get methods for field1 etc. As already mentioned, change your parameter type, so that it is not Map.

From mybatis documentation,

You can pass multiple parameters to a mapper method. If you do, they
will be named by their position in the parameter list by default, for
example: #{1}, #{2} etc. If you wish to change the name of the
parameters (multiple only), then you can use the @Param(“paramName”)
annotation on the parameter.

So, change your Mapper,

public interface CustomItemMapper 
{
    Integer insert(@Param("item")CustomItem item, @Param("extra") String someparam);
}

and change your xml to,

 <insert id="insert" useGeneratedKeys="false" parameterType="map" keyProperty="id">
    insert into CustomItem (id, column2, column3, column4, column5, column6)
        values (#{id}, #{item.field1}, #{item.field2}, #{item.field3}, #{item.field4}, #{extra})
  </insert>