Postgresql: how to create table only if it does not already exist?

Question

In Postgresql, how can I do a condition to create a table only if it does not already exist?

Code example appreciated.

Answer 1

This is an old question. I'm only bringing back to suggest another answer. Note: other better answers already exist, this is just for educational purposes.

The easiest way is to do what others have said; perform the CREATE TABLE if you want to keep the existing data, or perform a DROP IF EXISTS and then a CREATE TABLE, if you want a freshly created table.

Another alternative is to query the system table for its existence and proceed from there.

SELECT true FROM pg_tables WHERE tablename =  [AND schemaname = ];


In use:

-- schema independent:
SELECT true FROM pg_tables WHERE tablename = 'foo';

-- schema dependent:
SELECT true FROM pg_tables WHERE tablename = 'foo' AND schemaname = 'bar';


If it matches you'll have a true value, otherwise it should return an empty dataset.  You can use that value to determine if you need to perform a CREATE TABLE.
    

             

                                                        
            
            

              
                
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