动态 SQL ——之—— suffixOverrides & prefix & suffix

suffixOverrides 它的作用是移除所有指定在 suffixOverrides属性中的内容。 suffix Overrides ——>后缀 覆盖

<!-- keyProperty="id">
 
<insert id="insert" useGeneratedKeys="true">
	insert into Count
	<trim prefix="(" suffix=")" suffixOverrides=",">
		<if test="countType != null">
			CountType,
		</if>
		<if test="countKey != null">
			CountKey,
		</if>
		<if test="countValue != null">
			CountValue,
		</if>
		<if test="lastUpdateTime != null">
			LastUpdateTime,
		</if>
		<if test="remark != null">
			Remark,
		</if>
	</trim>
	<trim prefix="values (" suffix=")" suffixOverrides=",">
		<if test="countType != null">
			#{countType,jdbcType=VARCHAR},
		</if>
		<if test="countKey != null">
			#{countKey,jdbcType=VARCHAR},
		</if>
		<if test="countValue != null">
			#{countValue,jdbcType=INTEGER},
		</if>
		<if test="lastUpdateTime != null">
			getDate(),
		</if>
		<if test="remark != null">
			#{remark,jdbcType=VARCHAR},
		</if>
	</trim>
</insert>

根据入参和 SQL 慢慢体会使用 

参考文章