postgresql - Postgres drop database error: pq: cannot drop the currently open database

Question

I'm trying to drop the database I'm currently connected to like so, but I'm getting this error:

pq: cannot drop the currently open database

I don't really understand how I'm expected to drop the database if I have to close my connection, because then I don't think I will be able to use dbConn.Exec to execute my DROP DATABASE statement?

dbConn *sql.DB

func stuff() error {
  _, err := dbConn.Exec(fmt.Sprintf(`DROP DATABASE %s;`, dbName))
  if err != nil {
    return err
  }

  return dbConn.Close()
}

I guess I could connect to a different database and then execute it on that connection, but I'm not even sure if that'd work, and it seems really weird to have to connect to a new database just to drop a different database. Any ideas? Thanks.

question from:https://stackoverflow.com/questions/36502401/postgres-drop-database-error-pq-cannot-drop-the-currently-open-database

Answer 1

Because, you are trying to execute dropDb command on database, to which you have open connection.

According to postgres documentation:

You cannot be connected to the database you are about to remove. Instead, connect to template1 or any other database and run this command again.

This makes sense, because when you drop the entire database, all the open connection referencing to that database becomes invalid, So the recommended approach is to connect to different database, and execute this command again.

If you are facing a situation, where a different client is connected to the database, and you really want to drop the database, you can forcibly disconnect all the client from that particular database.

For example, to forcibly disconnect all clients from database mydb:

If PostgreSQL < 9.2

SELECT pg_terminate_backend(procpid) FROM pg_stat_activity WHERE datname = 'mydb';

Else

SELECT pg_terminate_backend(pid) FROM pg_stat_activity WHERE datname = 'mydb';

Note: This command requires superuser privileges.

Then, you can connect to different database, and run dropDb command again.