SQL - "Default" when creating a table - is it neccessary? - mysql

Question

Looking at examples of a standard SQL layout I see this:
CREATE TABLE IF NOT EXISTS siteUser (
id int(11) AUTO_INCREMENT PRIMARY KEY,
email varchar(64) NOT NULL UNIQUE KEY,
password varchar(255) NOT NULL
) ENGINE=InnoDB DEFAULT;
What is th purpose of the "DEFAULT" at the end of specifying the engine? Is there any need for it? I tried to find an explanation of it on tutorial websites but I didn't have any luck.
James

Answer 1

Are you sure it's not an error? I can't find any reference of a default parameter for the database engine in a create table statement. Also, your create table statement fails in SQLFiddle.com in both MySQL 5.1 and 5.5.
I think you might have misinterpreted the default as being part of the engine clause, while actually it was part of a charset or collate clause. For instance, this is valid, since default is an optional keyword in front of the charset clause:
CREATE TABLE IF NOT EXISTS siteUser (
id int(11) AUTO_INCREMENT PRIMARY KEY,
email varchar(64) NOT NULL UNIQUE KEY,
password varchar(255) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET = utf8;
I guess the charset and collate clauses can have the default keyword (which is practically meaningless by the way), because they specify a default charset or collation, but there is still a possibility to override this per column.
For a storage engine this would be silly. There is no 'default' storage engine for a single table. There is only one. Also, it wouldn't make sense if it would set the default for the whole database. Why would that be an option in a create table statement?

Answer 2

It is used to set ENGINE=InnoDB as the default engine. So one way is to either remove the Engine = INNODB from your create table statement
CREATE TABLE IF NOT EXISTS siteUser (
id int(11) AUTO_INCREMENT PRIMARY KEY,
email varchar(64) NOT NULL UNIQUE KEY,
password varchar(255) NOT NULL
)
DEMO
Or the other way which GolezTrol has suggested:
CREATE TABLE IF NOT EXISTS siteUser (
id int(11) AUTO_INCREMENT PRIMARY KEY,
email varchar(64) NOT NULL UNIQUE KEY,
password varchar(255) NOT NULL
) ENGINE=InnoDB DEFAULT charset = utf8;
DEMO
From the Manual: InnoDB as the Default MySQL Storage Engine
In previous versions of MySQL, MyISAM was the default storage engine.
In our experience, most users never changed the default settings. With
MySQL 5.5, InnoDB becomes the default storage engine. Again, we expect
most users will not change the default settings. But, because of
InnoDB, the default settings deliver the benefits users expect from
their RDBMS: ACID Transactions, Referential Integrity, and Crash
Recovery.
However if you want to make the INNODB as your deafult engine then there is one other way:
Under [mysqld] section in your ini file, add:
default-storage-engine = innodb
It is there in /etc/my.cnf