method

add_limit_offset!

v1.2.0 - Show latest stable - 1 note - Class: ActiveRecord::ConnectionAdapters::DB2Adapter

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add_limit_offset!(sql, options) public

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# File activerecord/lib/active_record/connection_adapters/db2_adapter.rb, line 93
        def add_limit_offset!(sql, options)
          if limit = options[:limit]
            offset = options[:offset] || 0
            # The following trick was added by andrea+rails@webcom.it.
            sql.gsub!(/SELECT/i, 'SELECT B.* FROM (SELECT A.*, row_number() over () AS internal$rownum FROM (SELECT')
            sql << ") A ) B WHERE B.internal$rownum > #{offset} AND B.internal$rownum <= #{limit + offset}"
          end
        end

April 14, 2011

0 thanks

Why gsub!

I notice other adapters use sql.sub!, not sql.gsub! and in fact I had trouble with adding the limit parameter to any query involving nested selects. Replacing sql.gsub! with sql.sub! solved that problem for me. Has anyone else had a similar experience with this method?

In other words, replace:

sql.gsub!(/SELECT/i, 'SELECT B.* FROM (SELECT A.*, row_number() over () AS internal$rownum FROM (SELECT')

With:

sql.sub!(/SELECT/i, 'SELECT B.* FROM (SELECT A.*, row_number() over () AS internal$rownum FROM (SELECT')

add_limit_offset!

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Why gsub!

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