How to put if condition in myBatis datamapper.xml

Question

Here is what I want

<update id='stoIncrement' parameterType='java.util.Map'>
update DB set 
<if test="#{is_increase} == 1">
count=(select max(count) from DB) +1 
 </if>
<if test="#{is_increase} == 0">
count=(select max(count) from DB) -1 
 </if>
where store=#{store}
</update>

Here is_increase is a key of the parameter map and is not an entity of the table.

But the above do not seem to work. Can someone help in this regards.

Thanks

Solution

use set like this:

<update id='stoIncrement' parameterType='java.util.Map'>
    update DB
    <set>
        <if test="is_increase !=null and  is_increase == 1">
            count=(select max(count) from DB) +1 ,
        </if>
        <if test="is_increase !=null and  is_increase == 0">
            count=(select max(count) from DB) -1 ,
        </if>
    </set>
    where store=#{store}
</update>

Comments

[SiddP]

The above approach gives the following exception gives the following exception : org.apache.ibatis.exceptions.IbatisException: ### Error updating database. Cause: java.lang.NumberFormatException: For input string: "{0=null}" Is there any mistake in this <if test="#{is_increase} == 1">

[Persia]

I update the test condition and check the null of is_increase