How to check for an empty string in MyBatis? - mybatis

Question

How do I check for an empty string in the dynamic SQL of MyBatis? I find the code below in the documentaiton, but I want to check for empty string, not null.
<select id="findActiveBlogWithTitleLike" parameterType="Blog" resultType="Blog">
SELECT * FROM BLOG WHERE state = ‘ACTIVE’
<if test="title != null">
AND title like #{title}
</if>
</select>

Answer 1

In MyBatis you can use != '' to compare with empty string, so in your query it would be something like:
<select id="findActiveBlogWithTitleLike" parameterType="Blog" resultType="Blog">
SELECT * FROM BLOG WHERE state = ‘ACTIVE’
<if test="title != null and title != ''">
AND title like #{title}
</if>
</select>

Answer 2

Dont't speak English well. Thank you for your patient.
It's functions xml file.
<mapper namespace="org.jacknie.mybatis.Functions">
<sql id="isBlank">
<bind name="isBlank" value=":[#org.apache.commons.lang3.StringUtils#isBlank(#this)]" />
</sql>
<sql id="sysout">
<bind name="sysout" value=":[#System#out.println(#this)]" />
</sql>
</mapper>
It's mapper xml file.
<mapper namespace="org.jacknie.test.TestMapper">
<select id="selectTest" resultType="_int">
<include refid="org.jacknie.mybatis.Functions.isBlank" />
<include refid="org.jacknie.mybatis.Functions.sysout" />
SELECT '1' FROM DUAL
<if test="#fn = isBlank, not(#fn(map.name))">
<bind name="forLogging" value="#fn = sysout, #fn('Hello' + map.name)" />
</if>
</select>
</mapper>
How about think this tip...
enter link description here