SQLITE FAQ:
(1) How do I create an AUTOINCREMENT field. Short answer: A column declared INTEGER PRIMARY KEY will autoincrement. Here is the long answer: Beginning with version SQLite 2.3.4, If you declare a column of a table to be INTEGER PRIMARY KEY, then whenever you insert a NULL into that column of the table, the NULL is automatically converted into an integer which is one greater than the largest value of that column over all other rows in the table, or 1 if the table is empty. For example, suppose you have a table like this: CREATE TABLE t1( a INTEGER PRIMARY KEY, b INTEGER ); With this table, the statement INSERT INTO t1 VALUES(NULL,123); is logically equivalent to saying: INSERT INTO t1 VALUES((SELECT max(a) FROM t1)+1,123); For SQLite version 2.2.0 through 2.3.3, if you insert a NULL into an INTEGER PRIMARY KEY column, the NULL will be changed to a unique integer, but it will a semi-random integer. Unique keys generated this way will not be sequential. For SQLite version 2.3.4 and beyond, the unique keys will be sequential until the largest key reaches a value of 2147483647. That is the largest 32-bit signed integer and cannot be incremented, so subsequent insert attempts will revert to the semi-random key generation algorithm of SQLite version 2.3.3 and earlier. Beginning with version 2.2.3, there is a new API function named sqlite_last_insert_rowid() which will return the integer key for the most recent insert operation. See the API documentation for details. -----Original Message----- From: Dynamix [mailto:[EMAIL PROTECTED] Sent: Monday, May 03, 2004 12:28 PM To: [EMAIL PROTECTED] Subject: [sqlite] Autoincrement of primary key Greetings, is it possible de have an autoincrement feature ?? i want to have something like : insert into table names (NULL, 'name1'); insert into table names (NULL, 'name2'); insert into table names (NULL, 'name3'); and then id will be 1,2 and 3 ? Any help please Hatem --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
