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41b92914f8
Initially, `TOP` was introduced to support `limit` for MSSQL database. Unlike PostgreSQL/MySQL/SQLite, MSSQL does not have native `LIMIT`/`OFFSET` support. The commit adding `TOP` is1a246f7161. However, it figured out that `TOP` implementation was weak and it's not sufficient to also support `OFFSET`, then `TOP` was substituted with `ROW_NUMBER()` subquery inbe48ed3071. This is a well known trick in MSSQL - https://stackoverflow.com/questions/2135418/equivalent-of-limit-and-offset-for-sql-server. So now we don't need this `visit_Arel_Nodes_Top` at all. It does nothing useful but also adds an extra space after `SELECT` when `LIMIT` is being used for **any** database.
44 lines
698 B
Ruby
44 lines
698 B
Ruby
# frozen_string_literal: true
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module Arel # :nodoc: all
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module Nodes
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class Unary < Arel::Nodes::NodeExpression
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attr_accessor :expr
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alias :value :expr
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def initialize(expr)
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super()
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@expr = expr
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end
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def hash
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@expr.hash
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end
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def eql?(other)
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self.class == other.class &&
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self.expr == other.expr
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end
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alias :== :eql?
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end
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%w{
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Bin
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Cube
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DistinctOn
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Group
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GroupingElement
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GroupingSet
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Lateral
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Limit
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Lock
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Not
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Offset
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On
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Ordering
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RollUp
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}.each do |name|
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const_set(name, Class.new(Unary))
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end
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end
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end
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