how to pass a constant value to nested column with mybaits association

问题

how can I pass constant value '1111' to a nested column with mybatis association?

<association property="certificateType" column="{VALUE=CERTIFICATE_TYPE,TYPE='1111'}" select="getDict"/>

回答1:

Depending on what your db is, you can use

IFNULL(#{TYPE}, '1111') (mysql)

ISNULL(#{TYPE}, '1111') (sql server)

In your subquery (getDict).

Another solution is that your parent query can return TYPE as a value

For example by saying:

SELECT '1111' AS TYPE, .....

Then in your column you can just say

column={VALUE=CERTIFICATE_TYPE,TYPE=TYPE}

Hope that helps.

来源：https://stackoverflow.com/questions/36230661/how-to-pass-a-constant-value-to-nested-column-with-mybaits-association