How do I check in SQLite whether a table exists?

Question

How do I, reliably, check in SQLite, whether a particular user table exists?

I am not asking for unreliable ways like checking if a "select *" on the table returned an error or not (is this even a good idea?).

The reason is like this:

In my program, I need to create and then populate some tables if they do not exist already.

If they do already exist, I need to update some tables.

Should I take some other path instead to signal that the tables in question have already been created - say for example, by creating/putting/setting a certain flag in my program initialization/settings file on disk or something?

Or does my approach make sense?

Answer 1

I missed that FAQ entry.

Anyway, for future reference, the complete query is:

SELECT name FROM sqlite_master WHERE type='table' AND name='{table_name}'; 

Where {table_name} is the name of the table to check.

Documentation section for reference: Database File Format. 2.6. Storage Of The SQL Database Schema

• This will return a list of tables with the name specified; that is, the cursor will have a count of 0 (does not exist) or a count of 1 (does exist)

Answer 2

If you're using SQLite version 3.3+ you can easily create a table with:

create table if not exists TableName (col1 typ1, ..., colN typN) 

In the same way, you can remove a table only if it exists by using:

drop table if exists TableName