This seems like it should have an easy solution, but I can't for the life of me find it. I want to query out all features in a layer that do not have a value. I did not create the data, all the features already have their attributes filled in, and there is no "null" value in the blank field I want to query. If I try to just say FIELD is not null in the definition query, everything still shows up including all the features with blank FIELD.
Hi, I believe I had the same problem with a text field in the table. I was able to make my query from the table using the "Select by Attribute" tool at the top of the table. In the Select by Attribute dialog I selected "Add Clause", and in that dialog selected my Attribute Field, the comparison value ("is equal to", "is not equal to", etc.), then click on the little slider button marked SQL. In the SQL dialog that comes up, the Clause comes in built except for the value you want to use. In this case where there is no value, I used two single quotes (ex. '' ,with no space). This selected the empty values in the field I was querying.
I tried these steps, but errors. Tool must have been improved. Now, tool allows you to select "is null", apply, and OK. Then, I selected delete from above menu. Nulls removed. Nice and easy.😁