Shulou(Shulou.com)05/31 Report--

This article mainly explains "what are the skills of database synchronization optimization". Interested friends may wish to take a look. The method introduced in this paper is simple, fast and practical. Next let the editor to take you to learn "what are the database synchronization optimization skills?"

Scenario 1: some fields of one table need to be synchronized to some fields of another table.

INSERT INTO table1 (a _ FROM table1 WHERE _ d) SELECTa,b,c,d FROM table2WHERE NOT EXISTS (SELECT * FROM table1 WHERE table2.`a` = table1.`b`)

When the last subquery has a record, it is skipped.

Scenario 2: add a field to the table that needs to be recalculated and updated to the table.

If you use the script, you can only update about 10 items without using transactions. If there is a corresponding algorithm, you can generate update statements first, and then update them.

Scenario 3 is associated with a table. A table field is updated to a field in batch.

UPDATE oto_payment AS an INNER JOIN oto_customer AS c ON a.openid=c.openid

SET a.customer_id=c.customer_id

At this point, I believe that we have a deeper understanding of "database synchronization optimization skills", might as well come to the actual operation of it! Here is the website, more related content can enter the relevant channels to inquire, follow us, continue to learn!

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