Remove Primary Key in MySQL

Without an index, maintaining an autoincrement column becomes too expensive, that’s why MySQL requires an autoincrement column to be a leftmost part of an index. You should remove the autoincrement property before dropping the key: Note that you have a composite PRIMARY KEY which covers all three columns and id is not guaranteed to be … Read more

How can I do ‘insert if not exists’ in MySQL?

Use INSERT IGNORE INTO table. There’s also INSERT … ON DUPLICATE KEY UPDATE syntax, and you can find explanations in 13.2.6.2 INSERT … ON DUPLICATE KEY UPDATE Statement. Post from bogdan.org.ua according to Google’s webcache: 18th October 2007 To start: as of the latest MySQL, syntax presented in the title is not possible. But there … Read more

How can I do ‘insert if not exists’ in MySQL?

Use INSERT IGNORE INTO table. There’s also INSERT … ON DUPLICATE KEY UPDATE syntax, and you can find explanations in 13.2.6.2 INSERT … ON DUPLICATE KEY UPDATE Statement. Post from bogdan.org.ua according to Google’s webcache: 18th October 2007 To start: as of the latest MySQL, syntax presented in the title is not possible. But there are several very easy ways to accomplish … Read more

MS Access error: relationships must be on same number of fields with the same data types

Make sure you have your VendorID set as the same datatype in both the tables. N.B: Even if it is stored as a number, make sure they are both long integers. The duplicates shouldn’t prevent you from creating a relationship: duplicates restrict only when you try and create a relationship with referential integrity.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)