WSO2DSS服务正在将空值转换为“”（一个空格）

我试图通过DSS服务调用db函数。该db函数基本上是为了更新数据库中的用户值而编写的，该值是从dss作为输入获取的

在my db函数中，如果它的输入值为null，它将不会更新我的postgres数据库中的用户详细信息，否则它将更新。我使用COALESCE函数实现了这一点。我单独测试了db函数的这个功能，它工作得很好

但当我通过dss将null值传递给函数时，dss会将null转换为单个空格并将其传递给函数。函数用于不接收带有单个空格的空更新数据库字段

因为这个问题，我不得不在COALESCE函数中编写更多的逻辑

我想知道为什么dss将空值转换为“”

我的数据库功能如下

CREATE OR REPLACE FUNCTION modify_user(customer_id_in character varying, email_id_in character varying, mobile_in character varying, first_name_in character varying, last_name_in character varying)
  RETURNS integer AS
$BODY$
BEGIN
     IF EXISTS (SELECT 1 FROM ildb_schema.customer_detail WHERE identifier = customer_id_in) THEN 
 UPDATE ildb_schema.customer_detail 
 SET first_name=COALESCE(first_name_in,first_name),
     last_name=COALESCE(last_name_in,last_name),
     mobile_number=COALESCE(mobile_in,mobile_number),
     email=COALESCE(email_id_in,email),
     last_modify=now() 
     WHERE identifier = customer_id_in 
     AND (first_name_in IS NOT NULL AND first_name_in IS DISTINCT FROM first_name 
   OR last_name_in IS NOT NULL AND last_name_in IS DISTINCT FROM last_name 
   OR mobile_in IS NOT NULL AND mobile_in IS DISTINCT FROM mobile_number 
   OR email_id_in IS NOT NULL AND email_id_in IS DISTINCT FROM email);
     RETURN 1;
     END IF;
     RETURN 0;
END;
$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;
ALTER FUNCTION ildb_schema.modify_user(character varying, character varying, character varying, character varying, character varying)
  OWNER TO postgres;

决策支持系统如下

<data name="update_test">
   <config id="ildb">
      <property name="carbon_datasource_name">test_database</property>
   </config>
    <query id="update_function" useConfig="ildb">
      <sql>select * from modify_user(:cid,:email,:mob,:fn,:ln)</sql>
      <result element="customer" rowName="">
         <element column="modify_user" name="modify_user" xsdType="string"/>
      </result>
      <param defaultValue="null" name="cid" sqlType="STRING"/>
      <param defaultValue="null" name="email" sqlType="STRING"/>
      <param defaultValue="null" name="mob" sqlType="STRING"/>
      <param defaultValue="null" name="fn" sqlType="STRING"/>
      <param defaultValue="null" name="ln" sqlType="STRING"/>
   </query>
      <operation name="update_function_op1">
      <call-query href="update_function">
         <with-param name="cid" query-param="cid"/>
         <with-param name="email" query-param="email"/>
         <with-param name="mob" query-param="mob"/>
         <with-param name="fn" query-param="fn"/>
         <with-param name="ln" query-param="ln"/>
      </call-query>
   </operation>
     <resource method="PUT" path="/update/function">
      <call-query href="update_function">
         <with-param name="cid" query-param="cid"/>
         <with-param name="email" query-param="email"/>
         <with-param name="mob" query-param="mob"/>
         <with-param name="fn" query-param="fn"/>
         <with-param name="ln" query-param="ln"/>
      </call-query>
   </resource>
</data>

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如果要将默认值设置为null，请将其设置为{null}。比如,

<param defaultValue="#{NULL}" name="name" sqlType="STRING"/>

有关更多信息，请参阅