Question

I have a table 1 in wordpress as

wp_term_relationships (
   object_id bigint(20),
   term_taxonomy_id bigint(20),
   term_order int(11)
)

and table 2 as

 wp_test (
    object_id bigint(20),
    term_taxonomy_id bigint(20)
)

Now I am trying to update wp_term_relationships with the values in wp_test as

update ignore wp_term_relationships m1 
inner join wp_test m2
on (m1.term_taxonomy_id = m2.term_taxonomy_id)
set m1.object_id = m2.object_id

However, all the values of wp_test do not get updated to wp_term_relationships

I have even tried straight up inserting the values from wp_test into wp_test_relationships

by using an insert as

insert ignore into wp_term_relationships(object_id, term_taxonomy_id)
select object_id, term_taxonomy_id from wp_test

But it just updates the term_taxonomy_id values with the corresponding object_id values as 0 or
object_id values with the corresponding term_taxonomy_id values as 0

How can I transfer these 2 columns from wp_test into wp_term_relationships

Answer 1

I think what you need is an INSERT without IGNORE and with ON DUPLICATE KEY UPDATE instead:

INSERT INTO 
  wp_term_relationships (object_id, term_taxonomy_id)
SELECT 
  object_id, 
  term_taxonomy_id 
  FROM wp_test
ON DUPLICATE KEY UPDATE 
  wp_term_relationships.term_taxonomy_id = VALUES(term_taxonomy_id)

Note that this assumes that you have a unique constraint on wp_term_relationships.object_id

edit for different case:

If you mean that what constitutes a "duplicate" is a distinct combination of the two columns, then you need to add a unique constraint on the two columns in MySQL, and then use your INSERT IGNORE query:

ALTER TABLE wp_term_relationships ADD UNIQUE (object_id, term_taxonomy_id);