Re: [SQL] Does PostgreSQL have an UPDATE Function like UNIFY?

"John J. Boris, Sr." <john(dot)boris(at)onlinesvc(dot)com> writes:
> I was wondering if PostgreSQL had a function that allowed you to update a
> table from a delimited file that would update matching records and insert
> new records. Under Unify you could do an update with a switch (I think it
> was -n) that would take input from a pipe delimited file (in the order the
> fields of the table) and since the table had which field was unique it
> would key on that and if it didn't find the key it would add the
> record.

Not directly, but I think you could solve it with a temporary table and
two or three SQL statements:

CREATE TABLE temp (just like the master)
COPY temp FROM delimited file
UPDATE master SET field1 = temp.field1, etc
WHERE master.key = temp.key
INSERT INTO master SELECT * FROM temp
WHERE NOT EXISTS (SELECT * FROM master WHERE key = temp.key)

There's probably a cleaner/more efficient way to do the last step...
but as long as you have an index on the key field it shouldn't be
too bad.

regards, tom lane