require 'arel/collectors/sql_string'
module Arel
class SelectManager < Arel::TreeManager
include Arel::Crud
STRING_OR_SYMBOL_CLASS = [Symbol, String]
def initialize engine, table = nil
super(engine)
@ast = Nodes::SelectStatement.new
@ctx = @ast.cores.last
from table
end
def initialize_copy other
super
@ctx = @ast.cores.last
end
def limit
@ast.limit && @ast.limit.expr.expr
end
alias :taken :limit
def constraints
@ctx.wheres
end
def offset
@ast.offset && @ast.offset.expr
end
def skip amount
if amount
@ast.offset = Nodes::Offset.new(amount)
else
@ast.offset = nil
end
self
end
alias :offset= :skip
###
# Produces an Arel::Nodes::Exists node
def exists
Arel::Nodes::Exists.new @ast
end
def as other
create_table_alias grouping(@ast), Nodes::SqlLiteral.new(other)
end
def lock locking = Arel.sql('FOR UPDATE')
case locking
when true
locking = Arel.sql('FOR UPDATE')
when Arel::Nodes::SqlLiteral
when String
locking = Arel.sql locking
end
@ast.lock = Nodes::Lock.new(locking)
self
end
def locked
@ast.lock
end
def on *exprs
@ctx.source.right.last.right = Nodes::On.new(collapse(exprs))
self
end
def group *columns
columns.each do |column|
# FIXME: backwards compat
column = Nodes::SqlLiteral.new(column) if String === column
column = Nodes::SqlLiteral.new(column.to_s) if Symbol === column
@ctx.groups.push Nodes::Group.new column
end
self
end
def from table
table = Nodes::SqlLiteral.new(table) if String === table
# FIXME: this is a hack to support
# test_with_two_tables_in_from_without_getting_double_quoted
# from the AR tests.
case table
when Nodes::Join
@ctx.source.right << table
else
@ctx.source.left = table
end
self
end
def froms
@ast.cores.map { |x| x.from }.compact
end
def join relation, klass = Nodes::InnerJoin
return self unless relation
case relation
when String, Nodes::SqlLiteral
raise if relation.blank?
klass = Nodes::StringJoin
end
@ctx.source.right << create_join(relation, nil, klass)
self
end
def having *exprs
@ctx.having = Nodes::Having.new(collapse(exprs, @ctx.having))
self
end
def window name
window = Nodes::NamedWindow.new(name)
@ctx.windows.push window
window
end
def project *projections
# FIXME: converting these to SQLLiterals is probably not good, but
# rails tests require it.
@ctx.projections.concat projections.map { |x|
STRING_OR_SYMBOL_CLASS.include?(x.class) ? Nodes::SqlLiteral.new(x.to_s) : x
}
self
end
def projections
@ctx.projections
end
def projections= projections
@ctx.projections = projections
end
def distinct(value = true)
if value
@ctx.set_quantifier = Arel::Nodes::Distinct.new
else
@ctx.set_quantifier = nil
end
end
def order *expr
# FIXME: We SHOULD NOT be converting these to SqlLiteral automatically
@ast.orders.concat expr.map { |x|
STRING_OR_SYMBOL_CLASS.include?(x.class) ? Nodes::SqlLiteral.new(x.to_s) : x
}
self
end
def orders
@ast.orders
end
def where_sql
return if @ctx.wheres.empty?
viz = Visitors::WhereSql.new @engine.connection
Nodes::SqlLiteral.new viz.accept(@ctx, Collectors::SQLString.new).value
end
def union operation, other = nil
if other
node_class = Nodes.const_get("Union#{operation.to_s.capitalize}")
else
other = operation
node_class = Nodes::Union
end
node_class.new self.ast, other.ast
end
def intersect other
Nodes::Intersect.new ast, other.ast
end
def except other
Nodes::Except.new ast, other.ast
end
alias :minus :except
def with *subqueries
if subqueries.first.is_a? Symbol
node_class = Nodes.const_get("With#{subqueries.shift.to_s.capitalize}")
else
node_class = Nodes::With
end
@ast.with = node_class.new(subqueries.flatten)
self
end
def take limit
if limit
@ast.limit = Nodes::Limit.new(Nodes.build_quoted(limit))
@ctx.top = Nodes::Top.new(Nodes.build_quoted(limit))
else
@ast.limit = nil
@ctx.top = nil
end
self
end
alias limit= take
def join_sql
return nil if @ctx.source.right.empty?
sql = visitor.dup.extend(Visitors::JoinSql).accept @ctx
Nodes::SqlLiteral.new sql
end
def join_sources
@ctx.source.right
end
def source
@ctx.source
end
class Row < Struct.new(:data) # :nodoc:
def id
data['id']
end
def method_missing(name, *args)
name = name.to_s
return data[name] if data.key?(name)
super
end
end
private
def collapse exprs, existing = nil
exprs = exprs.unshift(existing.expr) if existing
exprs = exprs.compact.map { |expr|
if String === expr
# FIXME: Don't do this automatically
Arel.sql(expr)
else
expr
end
}
if exprs.length == 1
exprs.first
else
create_and exprs
end
end
end
end