<trim prefix=““ suffix=““ suffixOverrides=““ prefixOverrides=““>
</trim>
prefix:在trim标签内sql语句加上前缀
suffix:在trim标签内sql语句加上后缀
suffixOverrides:指定去除多余的后缀内容,如:suffixOverrides=",",去除trim标签内sql语句多余的后缀","
prefixOverrides:指定去除多余的前缀内容
<insert id="方法名" parameterType="" useGeneratedKeys="" keyProperty="" >
insert into 表名
<trim prefix="(" suffix=")" suffixOverrides="," >
<if test="a != null" >
a ,
</if>
...........
</trim>
<trim prefix="values (" suffix=")" suffixOverrides="," >
<if test="a != null" >
#{a},
</if>
............
</trim>
<selectKey resultType="" order="" keyProperty="">
......
</selectKey>
</insert>
useGeneratedKeys=""
keyProperty=""