MyBatis `if` Tag Usage Guide

1 year ago
Sophia Anderson
1 minute

In MyBatis, you can use the if tag to dynamically concatenate SQL statements. Depending on the condition, the if tag can determine whether to include a certain segment of SQL statement. If the condition is met, the SQL statement will be executed; otherwise, it will be ignored.

For example, in the Mapper XML file, the if tag can be used as follows:

<select id="getUserById" parameterType="int" resultType="User">
    SELECT * FROM user
    <where>
        <if test="id != null">
            AND id = #{id}
        </if>
        <if test="name != null">
            AND name = #{name}
        </if>
    </where>
</select>

In the example above, if the parameter “id” is not empty, the SQL statement will be appended with “AND id = #{id}”; if “name” is not empty, “AND name = #{name}” will be appended to the SQL statement. This allows for dynamically constructing SQL queries based on the input parameters, enabling flexible SQL search operations.

bannerAds