change auto_increment within same table using subquery mysql

Question

I am using mysql. I have a database table with auto_increment counter set. Now because of a requirement I need to leave starting 100 ids free and move all existing records s

Answer 1

The parser does not support a subquery in the place you are trying to use it.

Here's the excerpt from the MySQL source, from sql/sql_yacc.yy:

create_table_option:
    . . .
    | AUTO_INC opt_equal ulonglong_num

What you should read there is that the AUTO_INCREMENT table option accepts only a single literal number, not an expression or a subquery or a variable or anything else. So you simply can't set the AUTO_INCREMENT in the same statement in which you do SELECT MAX(id)+1.

But you don't have to.

MySQL will never allocate an auto-increment id less than the largest value currently in the table. So if you have a table with id value 102, the next value allocated will be at least 103.

You can even try to set AUTO_INCREMENT=50 explicitly, but that will be increased automatically to MAX(id)+1.