Insert values in table only one column changes value - sql

Question

I've got a table with 2 columns,
GROUP PROJECTS
10001 1
10001 2
First column (GROUP) stays the same value 10001.
Second column (PROJECTS) changes values 3,5,9,100, etc. (I have 400 project ID's)
What would be to correct (loop?) statement to insert all 400 PROJECTS.
I used insert, values for smaller lists.
INSERT INTO table (GROUP_ID, PROJECTS) VALUES (10001, 1, 10001, 2, 10001, etc, 10001, etc);
I have the list in Excel (if needed I can create a Temp table with all 400 project ID's)
Thanks.

Answer 1

I typically write such inserts as:
INSERT INTO table(GROUP_ID, PROJECTS)
select 10001, 1 from dual union all
select 10001, 2 from dual union all
. . . ;
You should be able to generate the select statement pretty easily in Excel.

Answer 2

If the project IDs exist in their own table (or you can create one from your Excel data), then yu can get the list of values from there and cross-join those with all the group IDs:
insert into group_projects (group_id, project_id)
select g.group_id, p.project_id
from groups g
cross join projects p
where not exists (
select 1 from group_projects gp
where gp.group_id = g.group_id and gp.project_id = p.project_id
);
The where not exists() excludes all the existing pairs so you don't insert duplicates.
SQL Fiddle
If the groups don't have their own table then you can use the existing values from a subquery:
insert into group_projects (group_id, project_id)
select g.group_id, p.project_id
from (select distinct group_id from group_projects) g
cross join projects p
where not exists (
select 1 from group_projects gp
where gp.group_id = g.group_id and gp.project_id = p.project_id
);
You could use Gordon's approach to generate the project ID list as a subquery as well, if you didn't want to create a table for those.

Answer 3

I'd go with what I view as a simpler and much more readable solution... create the temp table with the data from Excel, then run this-
DECLARE
CURSOR c1
IS
SELECT project_id
FROM temp_table
WHERE project_id IS NOT NULL;
BEGIN
FOR rec in c1
LOOP
INSERT INTO table
VALUES (10001, rec.project_id);
COMMIT;
END LOOP;
END;
Seems cleaner than one giant insert statement or something complex with joins and sub-queries. If you wanted to make sure the value doesn't already exist in "table", add that criteria to the cursor select statement, or if you have constraints on the table add an exception handler in the loop.