Logo Questions Linux Laravel Mysql Ubuntu Git Menu
 

INSERT multiple records using ruby on rails active record

Is there a way to INSERT multiple records rather than one at a time?

I have a very very ugly rake task that is doing the following ...

        VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "PR", :election => "2000-03-07", :party => row[45], :participate => participated(row[45]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "GE", :election => "2000-11-07", :party => row[46], :participate => participated(row[46]))          VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "SP", :election => "2000-05-08", :party => row[47], :participate => participated(row[47]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "GE", :election => "2001-11-06", :party => row[48], :participate => participated(row[48]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "PR", :election => "2002-05-07", :party => row[49], :participate => participated(row[49]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "GE", :election => "2002-11-05", :party => row[50], :participate => participated(row[50]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "SP", :election => "2003-05-06", :party => row[51], :participate => participated(row[51]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "GE", :election => "2003-11-04", :party => row[52], :participate => participated(row[52]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "PR", :election => "2004-03-02", :party => row[53], :participate => participated(row[53]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "GE", :election => "2004-11-02", :party => row[54], :participate => participated(row[54]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "SP", :election => "2005-02-08", :party => row[55], :participate => participated(row[55]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "PR", :election => "2005-05-03", :party => row[56], :participate => participated(row[56]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "PR", :election => "2005-09-13", :party => row[57], :participate => participated(row[56]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "GE", :election => "2005-11-08", :party => row[58], :participate => participated(row[58]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "SP", :election => "2006-02-07", :party => row[59], :participate => participated(row[59]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "PR", :election => "2006-05-02", :party => row[60], :participate => participated(row[60]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "GE", :election => "2006-11-07", :party => row[61], :participate => participated(row[61]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "PR", :election => "2007-05-08", :party => row[62], :participate => participated(row[62]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "PR", :election => "2007-09-11", :party => row[63], :participate => participated(row[63]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "GE", :election => "2007-11-06", :party => row[64], :participate => participated(row[64]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "PR", :election => "2007-11-06", :party => row[65], :participate => participated(row[65]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "PR", :election => "2007-12-11", :party => row[66], :participate => participated(row[66]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "PR", :election => "2008-03-04", :party => row[67], :participate => participated(row[67]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "PR", :election => "2008-10-14", :party => row[68], :participate => participated(row[68]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "GE", :election => "2008-11-04", :party => row[69], :participate => participated(row[69]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "GE", :election => "2008-11-18", :party => row[70], :participate => participated(row[70]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "PR", :election => "2009-05-05", :party => row[71], :participate => participated(row[71]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "PR", :election => "2009-09-08", :party => row[72], :participate => participated(row[72]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "PR", :election => "2009-09-15", :party => row[73], :participate => participated(row[73]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "PR", :election => "2009-09-29", :party => row[74], :participate => participated(row[74]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "GE", :election => "2009-11-03", :party => row[75], :participate => participated(row[75]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "PR", :election => "2010-05-04", :party => row[76], :participate => participated(row[76]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "PR", :election => "2010-07-13", :party => row[77], :participate => participated(row[77]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "PR", :election => "2010-09-07", :party => row[78], :participate => participated(row[78]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "GE", :election => "2010-11-02", :party => row[79], :participate => participated(row[79]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "PR", :election => "2011-05-03", :party => row[80], :participate => participated(row[80]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "PR", :election => "2011-09-13", :party => row[81], :participate => participated(row[81]))         VoteRecord.create(:prospect_id => prospect.id, :state => "OH", :election_type => "GE", :election => "2011-11-08", :party => row[82], :participate => participated(row[82])) 

This has to be extremely inefficient and there must be a better way...

like image 470
JZ. Avatar asked Apr 05 '12 03:04

JZ.


People also ask

How do you insert multiple records using one command?

INSERT-SELECT-UNION query to insert multiple records Thus, we can use INSERT-SELECT-UNION query to insert data into multiple rows of the table. The SQL UNION query helps to select all the data that has been enclosed by the SELECT query through the INSERT statement.

How do I insert multiple records in a table?

Insertion in a table is a DML (Data manipulation language) operation in SQL. When we want to store data we need to insert the data into the database. We use the INSERT statement to insert the data into the database.

What is Active Record in Ruby?

Active Record is the M in MVC - the model - which is the layer of the system responsible for representing business data and logic. Active Record facilitates the creation and use of business objects whose data requires persistent storage to a database.


2 Answers

The create method takes also an array as parameter.

VoteRecord.create(   [     { :prospect_id => prospect.id, :state => "OH", :election_type => "GE", :election => "2011-11-08", :party => row[82], :participate => participated(row[82]) },     { :prospect_id => prospect.id, :state => "OH", :election_type => "PR", :election => "2011-09-13", :party => row[81], :participate => participated(row[81]) }     ...   ] ) 

However, this still executes one SQL query per entry instead of a single SQL query. It is more efficent, because it only has to create a single activerecord object under the hood.

If you are inserting many rows from the same client at the same time, use INSERT statements with multiple VALUES lists to insert several rows at a time. This is considerably faster (many times faster in some cases) than using separate single-row INSERT statements. If you are adding data to a nonempty table, you can tune the bulk_insert_buffer_size variable to make data insertion even faster. See Section 5.1.3, “Server System Variables”.

From the mysql page (but I guess it should be the same for other dbs)

like image 100
klump Avatar answered Sep 21 '22 14:09

klump


Unfortunately, it's not possible in Rails out of the box.

However, activerecord-import is a great gem for Rails 3.x that adds an import method to your model classes, and does exactly what you want as a single SQL insert statement.

like image 27
nonrectangular Avatar answered Sep 21 '22 14:09

nonrectangular