Can I insert into a field where it is defined as NULL?

ratso

Evening All,

Dont suppose anyone has the syntax for inserting into a field that is blank or defined as NULL?

thanks

Ratso

Lars_Berg

Do you want to insert null into a column?

insert into ogrish(ratso) values(null)

ratso

Sorry,

I dont think I explained that properly

What I meant to say was:

How do I INSERT into a field that is already defined as NULL

for example:

$sql = "INSERT INTO foo ($id_value)
VALUES ('$new_value') WHERE ($id_value) IS NULL";

(that didnt work)

The problem has come from where I have a table with lots of form dropdown fields that dropdowns on forms are populated with.

I have a page where I can add new values to the dropdown fields, but everytime I do, it starts a new row for the next value, therefore I have a table populated with lots of spaces, so I was wondering if I could make MySQL insert to the blank spaces, but when it doesnt find a blank field then it would INSERT anyway.

Thanks

Ratso

Lars_Berg

$sql = "update foo set $id_value = '$new_value' WHERE $id_value IS NULL";

ratso

Thanks for that Lars,

I had to get it to limit as it filled all the NULL fields in that particular dropdown field, but that done the trick

This solution though has created a new problem, if I have run out of NULL fields in a certain dropdown field, it will not INSERT, is there anyway I can tell MySQL that if it doesnt find a NULL field to INSERT anyway?

Thanks

Ratso

Lars_Berg

I don't see why you have inserted those "empty" rows.

Before inserting, do a check if that new value exists in the database, if not insert it. Or am I missing something? 😉

ratso

Mmm, its probably the way I have designed the table, it goes like this

I have a form where you create a new "client", within that table are dropdown menus for things like "local authority" and "ethnicity" etc

These are populated from a table called dropdowns.

The problem comes from another form where you can add a new dropdown value, say like "southampton" as a "local authority", so that these appear on the dropdowns on the client form page, its just that when you do this it creates a whole new row on the table. Therefore you have "southampton" created and the rest of the dropdown values are left blank. So each time you create a new dropdown value for whatever it creates a new row, thats why I wanted to use up the NULL spaces.

Its probably due to bad design on my part that this happens, but I am still learning as I go.

Anyway, thanks for all the help with the coding syntax, appreciate it!!

Thanks

Ratso