mybatis 参数为Integer型数据并赋值0时，0被当作空处理，解决及缘由

mybatis 参数为Integer型数据并赋值0时，0被当作空处理：

mybatis.xml中有if判断条件判断参数不为空时，赋值为0的Integer参数被mybatis判断为空， 不执行<if test="param != null and param != ''"></if>的sql。

解决方法： 判断非空改成：<if test="param != null"</if>

用到mybatis时，避免用0来作值

官方解释： https://commons.apache.org/proper/commons-ognl/language-guide.html

Interpreting Objects as Booleans Any object can be used where a boolean is required. OGNL interprets objects as booleans like this: If the object is a Boolean, its value is extracted and returned; If the object is a Number, its double-precision floating-point value is compared with zero; non-zero is treated as true, zero as false; If the object is a Character, its boolean value is true if and only if its char value is non-zero; Otherwise, its boolean value is true if and only if it is non-null.