In supported databases, it should be possible insert only new rows about activerecord-import HOT 5 CLOSED

It is. Have a UNIQUE key in the database, and do :on_duplicate_key_update => '1=1'

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@wycats, this works exactly as @saizai mentioned for MySQL using ON DUPLICATE KEY UPDATE support that's baked into MySQL.

PostgreSQL doesn't support this natively for bulk inserts that I'm aware of. All of the PostgreSQL solutions I've seen have involved database triggers or locking tables, copying to temporary table, massaging rows, dropping a table and then inserting from the temp one.

If you or anyone else knows of a more DB agnostic way to do this I'd love to make that happen.

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@wycats, I may have missed your request. You are only wanting to insert new rows (not insert and update at the same time, correct?

It's the auto-update part that I can't do in a DB-agnostic way, but simply inserting new rows may be feasible with what you suggest.

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BTW :on_duplicate_key_update => '1=1'' doesn't work.

:on_duplicate_key_update => Book.column_names does work, although the resulting SQL is verbose as it will contain a=values(a), b=values(b) etc.

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Postgres 9.5 and up now supports upsert functionality and activerecord-import has added support for it. There is also the option to use :on_duplicate_key_ignore.

So currently Postgres, MySQL, and SQLite have options for ignoring duplicate keys. At some point it would be nice if they all shared the same option for adding that to the sql statement. That can have its own issue opened though 😜

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