Can I alter a column in an sqlite table to AUTOINCREMENT after creation?

Question

Can I make a field AUTOINCREMENT after made a table? For example, if you create a table like this:

create table person(id integer primary key, n         


        

Answer 1

You can dump the content to a new table:

CREATE TABLE failed_banks_id (id integer primary key autoincrement, name text, city text, state text, zip integer, acquired_by text, close_date date, updated_date date);

INSERT INTO failed_banks_id(name, city, state, zip, acquired_by,close_date, updated_date)
SELECT name, city, state, zip, acquired_by,close_date, updated_date
FROM failed_banks;

And rename the table:

DROP TABLE failed_banks;
ALTER TABLE failed_banks_id RENAME TO failed_banks;

Answer 2

While the Sqlite site gives you an example how to do it with a table with only a three fields, it gets nasty with one of 30 fields. Given you have a table called OldTable with many fields, the first of which is "ID" filled with integers. Make a copy of your database for backup. Using the command program dot commands,

    .output Oldtable.txt
    .dump Oldtable
    Drop Table Oldtable;

Open Oldtable.txt in Microsoft Word or a grep like text editor. Find and Replace your Integer field elements with NULL.(You may need to adjust this to fit your fields). Edit the Create Table line so the field that was defined as Integer is now INTEGER PRIMARY KEY AUTOINCREMENT. Save as NewTable.txt

Back in the command program dot

   .read NewTable.txt

Done. ID is now autoincrement.

Answer 3

Yes, you can make a column which is autoincrement. Modify the table and add a column. Keep in mind that it is of type INTEGER Primary Key.

Answer 4

Yes Do you have phpmyadmin installed? I believe if you go to the 'structure' tab and look along the right columnn (where the field types are listed) - I think you can change a setting there to make it autoincrement. There is also a SQL query that will do the same thing.

Answer 5

Simplest way — Just export and re-import

It is possible, and relatively easy. Export the database as an sql file. Alter the SQL file and re-import:

  sqlite3 mydata.db .dump > /tmp/backup.sql
  vi /tmp/backup.sql
  mv mydata.db mydata.db.old
  sqlite3 mydata.db
  sqlite>.read /tmp/backup.sql

Answer 6

Background:

The new key will be unique over all keys currently in the table, but it might overlap with keys that have been previously deleted from the table. To create keys that are unique over the lifetime of the table, add the AUTOINCREMENT keyword to the INTEGER PRIMARY KEY declaration.

http://www.sqlite.org/faq.html#q1

SQLite limitations:

SQLite supports a limited subset of ALTER TABLE. The ALTER TABLE command in SQLite allows the user to rename a table or to add a new column to an existing table. It is not possible to rename a column, remove a column, or add or remove constraints from a table.

http://www.sqlite.org/lang_altertable.html

Hack seems to exist:

It appears that you can set

PRAGMA writable_schema=ON;

Then do a manual UPDATE of the sqlite_master table to insert an "id INTEGER PRIMARY KEY" into the SQL for the table definition. I tried it and it seems to work. But it is dangerous. If you mess up, you corrupt the database file.

http://www.mail-archive.com/sqlite-users@sqlite.org/msg26987.html