how to find the missing values in a mysql table from an array

Question

i hava a table with varchar primary key, that is a foreing key for some other tables.

Something like:

ID-------------NAME
1011001020-----product 1
1011001022-----product 2    
1011001025-----product 3

Then, i have this array

array(
    '1011001020',
    '1011001022',
    '1011001025',
    'x',
    'y'
)

This array will be used to insert values in another table with FK, so if any value is not an ID on the first table, the INSERT query will brake.

How do i find 'x' and 'y' before any attempt to insert. I would like to avoid selecting all ids from table one and make a PHP comparison, since there are a lot of records. I would rather a MySQL approach

Answer 1

I would suggest the following procedure:

• Create the table and insert all the values into the table.
• Remove the values that do not match.
• Add the foreign key constraint.

The second and third steps can be done easily in SQL:

delete from temporarytable
    where tt.otherid not in (select ot.otherid from othertable ot);

alter table temporarytable
    add constraint fk_othertable foreign key (otherid) references othertable(otherid);

You can load the data however you like. For speed, I would recommend load data infile .

Answer 2

give this a shot. Tested on server, products is the new table and inserted only rows found in the array from items table.

INSERT INTO  `products` (  `name` ) 
SELECT  `name` FROM  `items` WHERE  `vendor_id` IN ( 1,2,3,4,.... )