This is probably a silly question but i haven’t been able to find the answer yet.
I want to use a TEXT column with my own unique names as the primary key in a table.
the little section of code to define this looks something like this in my project:
...blahblah..."CREATE TABLE " + CAT_BUD_TAB + " (" + CAT_ITEM_ID + "_ID TEXT PRIMARY KEY, "...blahblah..
Will this work as i intend? Or perhaps i need to use “AS ID”? I only ever see single tables with _ID as an autoincrementing integer in. Also this was intended to be a foreign key in another table but since i designed my database i’ve read more information and i’m not sure that’ll really matter using android & SQLITE?
Thanks to the posters below but i’m a bit slow and not sure if i’m applying the info right, could you check?
So if i have a create statement like this:
"CREATE TABLE " + CAT_BUD_TAB + " (" + CAT_ITEM_ID + " TEXT PRIMARY KEY, " + IN_OUT + " TEXT, " + BUDGET_AMOUNT + " REAL, " + ACTUAL_AMOUNT_SPENT + " REAL, " + AMOUNT_STRAYED + " REAL, " + OVERBUDGET_TF + " INTEGER, " + AUTOSPEND_TF + " INTEGER);"
db.execSQL(“SELECT ID, ID AS CAT_ITEM_ID”)
Can i then use them interchangeably? am i even anywhere near close? haha sorry i am trying!
You can create and define tables as you wish, but if you will have to use the table via a CursorAdapter that won’t work without a tweak.
CursorAdapter: The Cursor must include a column named "_id" or this class will not work.
You must always issue a
select col1 as _id ... to work.
So it’s recommended to use
_id in the table schema, and if you like to use by some other name you could this this.
select _id, _id as customname ... so select the _id column twice with different names.
You can have anything you want as the primary key.
But if you for instance want to use a CursorAdapter that automatically shows items from a Cursor-query you need to have an integer column called _ID as this is used here.
But if this is not something you plan to use with your table, you can do what you want!
_id must be of type int in sqlite create (long in Java). Various classes assume that. As a result, you cannot use UUID for primary key.