Check if value is not null and not empty in a select querry-CodePudding

I have created a function in postgresql and specified the returned type as TABLE(id uuid, data boolean)

This is the code that I have tried:

BEGIN
  RETURN QUERY SELECT table.id, (table.data <> '') as data FROM table;
END

But it wil will return NULL for "data" when data is NULL in the table. I was expecting it to return FALSE.

Data column is storing a json and I am trying to check if the stored value is not null and not empty

How can I make this code work?

CodePudding user response：

Use is distinct from to use a null-safe comparison:

SELECT table.id, table.data is distinct from '' as data 
FROM table;

Another option is to treat an empty string like null:

SELECT table.id, nullif(table.data, '') is not null as data 
FROM table;