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

What I used to check whether or not a table exists (Java & PostgreSQL) prior to creating it. I hope this helps someone. The create table portion is not implemented here, just the check to see if a table already exists. Pass in a connection to the database and the tableName and it should return whether or not the table exists.

public boolean SQLTableExists(Connection connection, String tableName) {
    boolean exists = false;

    try {
        Statement stmt = connection.createStatement();
        String sqlText = "SELECT tables.table_name FROM information_schema.tables WHERE table_name = '" + tableName + "'";    
        ResultSet rs = stmt.executeQuery(sqlText);

        if (rs != null) {
            while (rs.next()) {
                if (rs.getString(1).equalsIgnoreCase(tableName)) {
                    System.out.println("Table: " + tableName + " already exists!");
                    exists = true;
                } else { 
                    System.out.println("Table: " + tableName + " does not appear to exist.");
                    exists = false;
                }

            }
        }

    } catch (SQLException sqlex) {
        sqlex.printStackTrace();
    }
    return exists;
}