问题
Is there an analog to CREATE TABLE IF NOT EXISTS for creating databases?
Background: I am writing a script to automatically set up the schema in PostgreSQL on an unknown system. I am not sure if the database (or even part of the schema) was already deployed, so I want to structure my code to not fail (or ideally even show errors) if some of the structure already exists. I want to differentiate the errors that prevent me from creating a database (so abort future schema changes since they will not work) from this error.
回答1:
No but you could query the pg_catalog.pg_database table to see if it exists.
来源：https://stackoverflow.com/questions/15815372/postgres-database-create-if-not-exists