PHP, script for moving db2 data from one database to another - php

Question

I need to port some data from tables on a development database into identical tables on the production database, but the production already has records with primary keys that match the dev database so I can't dump the data in with primary keysbundleRenderer.renderToStream
In this case, item_id is the primary key in the parent record, which is used to relate child records to it. Doing the insert of parent records will create a new primary key, so I need child inserts to also have the newly created primary key so that the relationship is maintained on the production databasebundleRenderer.renderToStream
my script so far:
<?php
$DB2connPROD = odbc_connect("schema","user", "pass");
$DB2connDEV = odbc_connect("schema","user", "pass");
//Get itemt records from dev
$getDevitems = "
select item_id,item_typet_id,item_identifier,expiration_timestamp
from development.itemt where item_typet_id in (2,3)
";
//$getDevitems will get records that have a primary key item_id which is used to get the records in the following select queries
foreach($getDevitems as $items){
//Get all comments
$getComments = "
select tc.item_id, tc.comment, tc.comment_type_id from development.item_commentt tc
inner join development.itemt t on tc.item_id = t.item_id
where t.item_id = {item_id_from_getDevitems}
";
$insertitem = "INSERT into production (item_identifier,expiration_timestamp)
values (item_identifier,expiration_timestamp)";
$insertComment = "INSERT into productionComment (item_id, comment, comment_type_id)
values (item_id, comment, comment_type_id)";
}
?>
So if $getDevitems returns
item_id | item_typet_id | item_identifier | expiration_timestamp
----------------------------------------------------------------------------
123 1 544 '2020-03-01 12:00:00'
I would want it to now run the comment select with 123 as the ID in the where clause:
select tc.item_id, tc.comment, tc.comment_type_id from development.item_commentt tc
inner join development.itemt t on tc.item_id = t.item_id
where t.item_id = 123
Now for my legacy parent record I have all of the parent data and all of the relational child data. so I want to insert the new parent record into the database, creating the new ID, and inserting the child record with the newly created primary key/ID. So for the new parent record I would do:
$insertitem = "INSERT into production (item_identifier,expiration_timestamp)
values (544,'2020-03-01 12:00:00')";
Let's say that creates the new record with item_id = 43409. I want my comment insert to be:
$insertComment = "INSERT into productionComment (item_id, comment, comment_type_id)
values (43409, comment, comment_type_id)";
Bottom LIne: I need to take relational data (all based on item_id) from a development database, and insert these into a new database which creates a new primary key but I need to keep the relationship.
How can I properly finish this to do what I need and make sure I maintain the full relationship for each originally selected item?

Answer 1

Given that your inserts are:
$insertitem = "INSERT into production (item_identifier,expiration_timestamp)
values (item_identifier,expiration_timestamp)";
$insertComment = "INSERT into productionComment (item_id, comment, comment_type_id)
values (item_id, comment, comment_type_id)";
It looks like you are using an identity column for item_id. You can retrieve the most recent generated identity value using the IDENTITY_VAL_LOCAL() function so the second insert should be:
$insertComment = "INSERT into productionComment (item_id, comment, comment_type_id)
values (IDENTITY_VAL_LOCAL(), comment, comment_type_id)";

Answer 2

I cannot help with PHP but with DB2 for IBMi you have different solutions :
If i understand it correctly item_id is a GENERATED ALWAYS as IDENTITY column
You can get newly created item_id using
select item_id from final table (
INSERT into production (item_identifier,expiration_timestamp)
values (544,'2020-03-01 12:00:00')
)
Or you can force value of item_id with dev value or your own increment
INSERT into production (idtem_id, item_identifier,expiration_timestamp)
values (<your value>, 544,'2020-03-01 12:00:00')
OVERRIDING SYSTEM VALUE
In this case you will have to set next value for item_id by issueing
alter table production alter column item_id restart with <restart value>