module Arel
class SelectManager < Arel::TreeManager
include Arel::Crud
def initialize engine, table = nil
super(engine)
@ast = Nodes::SelectStatement.new
@ctx = @ast.cores.last
from table
end
def taken
@ast.limit
end
def constraints
@ctx.wheres
end
def skip amount
@ast.offset = Nodes::Offset.new(amount)
self
end
###
# Produces an Arel::Nodes::Exists node
def exists
Arel::Nodes::Exists.new @ast
end
def where_clauses
#warn "where_clauses is deprecated" if $VERBOSE
to_sql = Visitors::ToSql.new @engine
@ctx.wheres.map { |c| to_sql.accept c }
end
def lock locking = true
# FIXME: do we even need to store this? If locking is +false+ shouldn't
# we just remove the node from the AST?
@ast.lock = Nodes::Lock.new
self
end
def locked
@ast.lock
end
def on *exprs
@ctx.froms.constraint = 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.
if @ctx.froms
source = @ctx.froms
if Nodes::SqlLiteral === table && Nodes::Join === source
source.left = table
table = source
end
end
@ctx.froms = table
self
end
def join relation, klass = Nodes::InnerJoin
return self unless relation
case relation
when String, Nodes::SqlLiteral
raise if relation.blank?
from Nodes::StringJoin.new(@ctx.froms, relation)
else
from klass.new(@ctx.froms, relation, nil)
end
end
def having expr
expr = Nodes::SqlLiteral.new(expr) if String === expr
@ctx.having = Nodes::Having.new(expr)
self
end
def project *projections
# FIXME: converting these to SQLLiterals is probably not good, but
# rails tests require it.
@ctx.projections.concat projections.map { |x|
[Symbol, String].include?(x.class) ? SqlLiteral.new(x.to_s) : x
}
self
end
def where expr
@ctx.wheres << expr
self
end
def order *expr
# FIXME: We SHOULD NOT be converting these to SqlLiteral automatically
@ast.orders.concat expr.map { |x|
String === x || Symbol === x ? Nodes::SqlLiteral.new(x.to_s) : x
}
self
end
def orders
@ast.orders
end
def wheres
Compatibility::Wheres.new @engine, @ctx.wheres
end
def where_sql
return if @ctx.wheres.empty?
viz = Visitors::WhereSql.new @engine
Nodes::SqlLiteral.new viz.accept @ctx
end
def take limit
@ast.limit = limit
self
end
def join_sql
return nil unless @ctx.froms
viz = Visitors::JoinSql.new @engine
Nodes::SqlLiteral.new viz.accept @ctx
end
def order_clauses
Visitors::OrderClauses.new(@engine).accept(@ast).map { |x|
Nodes::SqlLiteral.new x
}
end
def joins manager
if $VERBOSE
warn "joins is deprecated and will be removed in 2.2"
warn "please remove your call to joins from #{caller.first}"
end
manager.join_sql
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
def to_a # :nodoc:
warn "to_a is deprecated. Please remove it from #{caller[0]}"
# FIXME: I think `select` should be made public...
@engine.connection.send(:select, to_sql, 'AREL').map { |x| Row.new(x) }
end
# FIXME: this method should go away
def insert values
im = InsertManager.new @engine
table = @ctx.froms
primary_key_name = (primary_key = table.primary_key) && primary_key.name
# FIXME: in AR tests values sometimes were Array and not Hash therefore is_a?(Hash) check is added
primary_key_value = primary_key && values.is_a?(Hash) && values[primary_key]
im.into table
im.insert values
# Oracle adapter needs primary key name to generate RETURNING ... INTO ... clause
# for tables which assign primary key value using trigger.
# RETURNING ... INTO ... clause will be added only if primary_key_value is nil
# therefore it is necessary to pass primary key value as well
@engine.connection.insert im.to_sql, 'AREL', primary_key_name, primary_key_value
end
private
def collapse exprs
return exprs.first if exprs.length == 1
right = exprs.pop
left = exprs.pop
right = Nodes::SqlLiteral.new(right) if String === right
right = Nodes::And.new left, right
exprs.reverse.inject(right) { |memo,expr|
Nodes::And.new(expr, memo)
}
end
end
end