mybatis動態sql中的trim標籤的使用

trim標記是乙個格式化的標記，可以完成set或者是where標記在xml檔案當中的功能

總結：

trim標籤  拼接字串

prefixoverrides：去掉拼串後的字串的第乙個字首 一般是 and 或 or
suffixoverrides：去掉拼串後字串的最後乙個字尾 一般是 and 或 or
set標籤：在更新中使用，可以去除多餘的逗號

查詢的情況：

"findbyemptrim" parametertype=

"employee" resulttype=
"employee"
>
select * from tbl_employee
"where" prefixoverrides=
"and | or" suffixoverrides=
"and | or"
>
<
if test=
"id!=null and id!=''"
>
and id=#
>
<
if test=
"lastname!=null and lastname!=''"
>
and last_name like #
>
<
if test=
"email!=null and email!=''"
>
and email like #
>
<
if test=
"gender!=null and gender!=''"
>
and gender = # and
>
<
/trim>
<
/select>

and id=#  and last_name like # and email like # and gender = # and

執行列印的sql

select * from tbl_employee where id=

? and last_name like ? and email like ? and gender =
?

"updatebyemptrim"  parametertype=

"employee"
>
update tbl_employee
"set" suffix=
"where id = #" suffixoverrides=
",">
<
if test=
"lastname!=null and lastname!=''"
>
last_name = #
,>
<
if test=
"email!=null and email!=''"
>
email = #
,>
<
if test=
"gender!=null and gender!=''"
>
gender = #
,>
<
/trim>
<
/select>

last_name = #

,email = #
,gender = #
,

執行列印的sql

update tbl_employee set last_name =

?, email =
?, gender =
? where id =
?

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