MySQL Database FAQ

One

Q: If there is a table, there is a field ID of the self-increment primary key, when the table has been inserted 10 data, deleted the ID of 8,9,10 data, and then restart the MySQL, and then insert a data, then this data ID value should be how much, is 8, or 11?
A: If the table type is MyISAM, then it is 11. If the table is of type InnoDB, the ID is 8.
This is because the maximum ID records stored by the two types of storage engines are different, the MyISAM table records the maximum ID into the data file, and the maximum ID value for restarting the MySQL self-increment primary key is not lost;
InnoDB, in turn, records the maximum ID value into memory, so the maximum ID value will be lost after restarting MySQL or optimize the table.

MySQL Database FAQ