WSO2 MI Validators and Array query parameters for a Data Service - wso2

Question

I don't know how to create a validator for 2 variables:
Q1. An user code that needs to be checked if exists prior to running the SQL query. I have an endpoint to check if the user code exists or not, how do I make it into a validator?
Q2. An array of dates, the best I could do was to use a pattern validator. I know there's also the possibility to set a parameter with paramType="array" and sqlType="date", but how can I configure this in the query parameters of the resource?
Please check the Data Service definition below:
<data name="APIDataService" serviceNamespace="" serviceGroup="" transports="http https local">
<description />
<config id="postgresDataService">
<property name="carbon_datasource_name">APIPostgres</property>
</config>
<!-- TODO: Q1. Here is the resource I want to use to validate the user code -->
<query id="validateUserCode" useConfig="postgresDataService">
<sql>
SELECT ( EXISTS ( SELECT 1
FROM user
WHERE code ILIKE :user_code ) )::INT AS does_user_exist
</sql>
<param name="user_code" sqlType="string" />
<result element="result">
<element column="does_user_exist" name="doesUserExist" xsdType="integer" />
</result>
</query>
<resource method="GET" path="validateUserCode">
<call-query href="validateUserCode">
<with-param name="user_code" query-param="user_code" />
</call-query>
</resource>
<query id="apiReportUserTotalEventsByDay" useConfig="postgresDataService">
<sql>
SELECT
calendar_date,
record_date,
user_code,
event_type_id,
event_count
FROM user_event
WHERE 1=1
AND calendar_date BETWEEN :calendar_date_start AND :calendar_date_end
AND record_date = ANY( ('{'||:record_date_array||'}')::DATE[] )
AND user_code = :user_code
</sql>
<!-- TODO: Q1. Here is the user code I want to validate -->
<param name="user_code" paramType="scalar" sqlType="string" />
<param name="calendar_date_start" paramType="scalar" sqlType="date" />
<param name="calendar_date_end" paramType="scalar" sqlType="date" />
<!-- TODO: Q2. Here is the array of date that I want to know
how I could convert into an paramType="array" sqlType="date" -->
<param name="record_date_array" paramType="scalar" sqlType="string" >
<validatePattern pattern="\s*\d{4}-\d{2}-\d{2}\s*(,\s*\d{4}-\d{2}-\d{2}\s*)*" />
</param>
<result element="result">
<element column="calendar_date" name="calendar_date" xsdType="string" />
<element column="record_date" name="record_date" xsdType="string" />
<element column="user_code" name="user_code" xsdType="string" />
<element column="event_type_id" name="event_type_id" xsdType="integer" />
<element column="event_count" name="event_count" xsdType="integer" />
</result>
</query>
<resource method="GET" path="apiReportUserTotalEventsByDay">
<call-query href="apiReportUserTotalEventsByDay">
<with-param name="user_code" query-param="user_code" />
<with-param name="calendar_date_start" query-param="calendar_date_start" />
<with-param name="calendar_date_end" query-param="calendar_date_end" />
<with-param name="record_date_array" query-param="record_date_array" />
</call-query>
</resource>
</data>