Filter: _is_null AND _is_not_null

[David Tandberg-Johansen]

Hi,

Trying to figure out the filter operators _is_null AND _is_not_null 

They demand a value, but i can't figure out what the value should be.

I see in the schema documentation that there are different *_FilterClause._is_null for the different datatypes. If someone could examplify i would appreciate it

[David Tandberg-Johansen]

Hi @Marius Bancila

Thank you for explaining the use 

[Marius Bancila · Accepted solution]

The operators _is_null and _is_not_null are mainly intended for BLOB columns because the others are typically not allowed to be null.

Since BLOBs are represented as base64-encoded strings, the type expected for these operators is String. However, of course, you're not supposed to pass any actual value, just something that's going to be ignored, such a an empty string:

query read_orders_attachments($cid : Int)
{
	useCompany(no: $cid)
  {
  	orderAttachment(filter :{fileData : {_is_null : ""}})
    {
      items
      {
        orderNo
        fileNo
        fileType
        fileData
      }
    }
  }
}

However, running this query will raise the following error:

"Unknown data type for column with id 16526."

We will release a fix for this issue.