diff options
Diffstat (limited to 'lib/arel/visitors')
| -rw-r--r-- | lib/arel/visitors/depth_first.rb | 2 | ||||
| -rw-r--r-- | lib/arel/visitors/dot.rb | 1 | ||||
| -rw-r--r-- | lib/arel/visitors/mssql.rb | 68 | ||||
| -rw-r--r-- | lib/arel/visitors/to_sql.rb | 11 | ||||
| -rw-r--r-- | lib/arel/visitors/visitor.rb | 12 |
5 files changed, 76 insertions, 18 deletions
diff --git a/lib/arel/visitors/depth_first.rb b/lib/arel/visitors/depth_first.rb index 914b2d1999..6f9385de1b 100644 --- a/lib/arel/visitors/depth_first.rb +++ b/lib/arel/visitors/depth_first.rb @@ -22,6 +22,7 @@ module Arel alias :visit_Arel_Nodes_Not :unary alias :visit_Arel_Nodes_Offset :unary alias :visit_Arel_Nodes_On :unary + alias :visit_Arel_Nodes_Ordering :unary alias :visit_Arel_Nodes_Top :unary alias :visit_Arel_Nodes_UnqualifiedColumn :unary @@ -75,7 +76,6 @@ module Arel alias :visit_Arel_Nodes_NotEqual :binary alias :visit_Arel_Nodes_NotIn :binary alias :visit_Arel_Nodes_Or :binary - alias :visit_Arel_Nodes_Ordering :binary alias :visit_Arel_Nodes_OuterJoin :binary alias :visit_Arel_Nodes_TableAlias :binary alias :visit_Arel_Nodes_Values :binary diff --git a/lib/arel/visitors/dot.rb b/lib/arel/visitors/dot.rb index 92d05c7b67..8303279211 100644 --- a/lib/arel/visitors/dot.rb +++ b/lib/arel/visitors/dot.rb @@ -30,7 +30,6 @@ module Arel private def visit_Arel_Nodes_Ordering o visit_edge o, "expr" - visit_edge o, "direction" end def visit_Arel_Nodes_TableAlias o diff --git a/lib/arel/visitors/mssql.rb b/lib/arel/visitors/mssql.rb index ea7ab6394c..23dc06a936 100644 --- a/lib/arel/visitors/mssql.rb +++ b/lib/arel/visitors/mssql.rb @@ -3,21 +3,71 @@ module Arel class MSSQL < Arel::Visitors::ToSql private - def build_subselect key, o - stmt = super - core = stmt.cores.first - core.top = Nodes::Top.new(o.limit.expr) if o.limit - stmt + # `top` wouldn't really work here. I.e. User.select("distinct first_name").limit(10) would generate + # "select top 10 distinct first_name from users", which is invalid query! it should be + # "select distinct top 10 first_name from users" + def visit_Arel_Nodes_Top o + "" end - def visit_Arel_Nodes_Limit o - "" + def visit_Arel_Nodes_SelectStatement o + if !o.limit && !o.offset + return super o + end + + select_order_by = "ORDER BY #{o.orders.map { |x| visit x }.join(', ')}" unless o.orders.empty? + + is_select_count = false + sql = o.cores.map { |x| + core_order_by = select_order_by || determine_order_by(x) + if select_count? x + x.projections = [row_num_literal(core_order_by)] + is_select_count = true + else + x.projections << row_num_literal(core_order_by) + end + + visit_Arel_Nodes_SelectCore x + }.join + + sql = "SELECT _t.* FROM (#{sql}) as _t WHERE #{get_offset_limit_clause(o)}" + # fixme count distinct wouldn't work with limit or offset + sql = "SELECT COUNT(1) as count_id FROM (#{sql}) AS subquery" if is_select_count + sql end - def visit_Arel_Nodes_Top o - "TOP #{visit o.expr}" + def get_offset_limit_clause o + first_row = o.offset ? o.offset.expr.to_i + 1 : 1 + last_row = o.limit ? o.limit.expr.to_i - 1 + first_row : nil + if last_row + " _row_num BETWEEN #{first_row} AND #{last_row}" + else + " _row_num >= #{first_row}" + end end + def determine_order_by x + unless x.groups.empty? + "ORDER BY #{x.groups.map { |g| visit g }.join ', ' }" + else + "ORDER BY #{find_left_table_pk(x.froms)}" + end + end + + def row_num_literal order_by + Nodes::SqlLiteral.new("ROW_NUMBER() OVER (#{order_by}) as _row_num") + end + + def select_count? x + x.projections.length == 1 && Arel::Nodes::Count === x.projections.first + end + + # fixme raise exception of there is no pk? + # fixme!! Table.primary_key will be depricated. What is the replacement?? + def find_left_table_pk o + return visit o.primary_key if o.instance_of? Arel::Table + find_left_table_pk o.left if o.kind_of? Arel::Nodes::Join + end end end end diff --git a/lib/arel/visitors/to_sql.rb b/lib/arel/visitors/to_sql.rb index 312f92ea2f..933edc15f2 100644 --- a/lib/arel/visitors/to_sql.rb +++ b/lib/arel/visitors/to_sql.rb @@ -203,8 +203,12 @@ key on UpdateManager using UpdateManager#key= "(#{visit o.expr})" end - def visit_Arel_Nodes_Ordering o - "#{visit o.expr} #{o.descending? ? 'DESC' : 'ASC'}" + def visit_Arel_Nodes_Ascending o + "#{visit o.expr} ASC" + end + + def visit_Arel_Nodes_Descending o + "#{visit o.expr} DESC" end def visit_Arel_Nodes_Group o @@ -416,7 +420,8 @@ key on UpdateManager using UpdateManager#key= end def quote_table_name name - @quoted_tables[name] ||= Arel::Nodes::SqlLiteral === name ? name : @connection.quote_table_name(name) + return name if Arel::Nodes::SqlLiteral === name + @quoted_tables[name] ||= @connection.quote_table_name(name) end def quote_column_name name diff --git a/lib/arel/visitors/visitor.rb b/lib/arel/visitors/visitor.rb index c9cdf34adb..8f9dd929e1 100644 --- a/lib/arel/visitors/visitor.rb +++ b/lib/arel/visitors/visitor.rb @@ -11,15 +11,19 @@ module Arel hash[klass] = "visit_#{(klass.name || '').gsub('::', '_')}" end + def dispatch + DISPATCH + end + def visit object - send DISPATCH[object.class], object + send dispatch[object.class], object rescue NoMethodError => e - raise e if respond_to?(DISPATCH[object.class], true) + raise e if respond_to?(dispatch[object.class], true) superklass = object.class.ancestors.find { |klass| - respond_to?(DISPATCH[klass], true) + respond_to?(dispatch[klass], true) } raise(TypeError, "Cannot visit #{object.class}") unless superklass - DISPATCH[object.class] = DISPATCH[superklass] + dispatch[object.class] = dispatch[superklass] retry end end |