(I'd like to know if I should be dropping and recreating the indexes, too, or if MySQL will do what I'm hoping. I looked through the MySQL reference guide for ALTER TABLE, and I found mention that if the size of a column is decreased to less than an index's length then the index will be shortened, but I couldn't find anything indicating what would happen to an index if the underlying column grows in size. But my question is, does MySQL update this key to be applicable for BIGINTs, or does it maintain only INT capabilities? Now, I've noticed that when doing these modifications, the key FK1 is still present after the constraint is dropped, and I assume it's still applicable after the constraint is recreated. MODIFY ID BIGINT(20) NOT NULL AUTO_INCREMENT,ĪLTER TABLE FactTable MODIFY ID BIGINT(20) NOT NULL AUTO_INCREMENT ĪLTER TABLE AttemptTable ADD CONSTRAINT FK1 FOREIGN KEY (FactID) So the course of my updates has been: ALTER TABLE AttemptTable DROP FOREIGN KEY FK1, Where AttemptTable has KEY FK1 (FactID) and CONSTRAINT FK1 FOREIGN KEY (FactID) REFERENCES FactTable (ID). | ID | int(11) | NO | PRI | NULL | auto_increment | | Field | Type | Null | Key | Default | Extra | I'm using MySQL version 5.0.82 with InnoDB tables.

In MySQL there are three main data types: string, numeric, and. The data type is a guideline for SQL to understand what type of data is expected inside of each column, and it also identifies how SQL will interact with the stored data. I'm in the process of updating my AUTO_INCREMENT PRIMARY KEY ID columns from INT to BIGINT. An SQL developer must decide what type of data that will be stored inside each column when creating a table.

Mysql alter column type