Question

I have 2 tables that I am working with that use the same column; one table contains the text and the other table contains the images; they use the column listing_id so that the right text shows up with the right images;

my problem is that because column listing_id is auto-increment, my first table is able to have an insert into query that is able to insert the text and then +1 the column listing_id; however the 2nd table I use another INSERT INTO query will not have the right listing_id,

because some entries for listing_id have been deleted, meaning that the 2nd table’s listing_id will always be behind the 1st tables listing_id;

how do I reference the column listing_id?

Answer 1

You need to create an INT column called something like “parent_id” in the dependant tables that stores the id of the main table that it is referencing. When you select records from the first, you would then JOIN the tables with the auto_increment field of the first field against the “parent_id” of the second.

As MrSlayer mentions, use the newly inserted ID of the first table to update “parent_id”. You should typically have a unique ID field in the second table for uniqueness, but it shouldn’t be part of the relationship to the first table.

If you’re unclear about how to get the id that the first table auto_increments to when you insert, use mysql_insert_id().

mysql_query("INSERT INTO table1 ...");
echo "Last inserted record_id in table1 was " .  mysql_insert_id();

INSERT INTO table1 (mytextcolumn) VALUES('text');
INSERT INTO table2 (parent_id,image_name) VALUES(LAST_INSERT_ID(),'someimage.png');