How do I fetch column names from a db table into an array, using PostgreSQL and Ruby?

问题

How can I iterate through all of the column headers in a table for a given database and add each column name individually to an array?

I know I can gather all of the information from the table using SELECT * FROM my_table but I need to work with just the column headers at this point. What is the best way to accomplish this?

回答1:

Are you using the pg gem? If so, you can try this:

require 'pg'

# `db_config` must contain your database configuration
conn = PG::Connection.open(db_config)

column_names = conn.query("SELECT * FROM my_table LIMIT 1").first.keys

回答2:

I recommend using

select column_name from information_schema.columns where table_name='my_table' 

as

SELECT * FROM my_table LIMIT 1 

will not return column names if the table is empty.

http://www.postgresql.org/message-id/AANLkTilsjTAXyN5DghR3M2U4c8w48UVxhov4-8igMpd1@mail.gmail.com

来源：https://stackoverflow.com/questions/26986443/how-do-i-fetch-column-names-from-a-db-table-into-an-array-using-postgresql-and