对于
// ProductMapper.java
List<Product> likeTest(@Param("name") String name);可能有空指针异常(NPE)
<bind name="likeName" value="'%'+ value +'%'"/>
SELECT *FROM
mall_productWHERE name LIKE #{likeName}不会有空指针异常(NPE)
1.-在XML中处理 null 值
<choose>
<when test="value">
<bind name="likeName" value="'%'+ value +'%'"/>
</when>
<otherwise>
<bind name="likeName" value="'%%'"/>
</otherwise>
</choose>
SELECT *
FROM mall_product
WHERE name LIKE #{likeName}2-在java代码中处理null值
if (name != null) {
name = "%" + name + "%";
} else {
name = "%%";
}
productMapper.likeTest(name);