# HG changeset patch
# User jbe
# Date 1287243808 -7200
# Node ID 56648d7917b18800933874280b8c6ed24100f16d
# Parent  3480a11da8e86a9bfcc141d13b224ecbf458a34f
Added method <db_selector>:add_with(...) to create queries WITH RECURSIVE

diff -r 3480a11da8e8 -r 56648d7917b1 libraries/mondelefant/mondelefant.lua
--- a/libraries/mondelefant/mondelefant.lua	Wed Oct 13 20:48:44 2010 +0200
+++ b/libraries/mondelefant/mondelefant.lua	Sat Oct 16 17:43:28 2010 +0200
@@ -58,6 +58,7 @@
 local function init_selector(self, db_conn)
   self._db_conn = db_conn
   self._mode = "list"
+  self._with = { sep = ", " }
   self._fields = { sep = ", " }
   self._distinct = false
   self._distinct_on = {sep = ", ", expression}
@@ -141,6 +142,21 @@
 --//--
 
 --[[--
+db_selector =
+<db_selector>:add_with(
+  expression = expression,
+  selector   = selector
+)
+
+Adds an WITH RECURSIVE expression to the selector. The selector is modified and returned.
+--]]--
+function selector_prototype:add_with(expression, selector)
+  add(self._with, {"$ AS ($)", {expression}, {selector}})
+  return self
+end
+--//--
+
+--[[--
 db_selector =                   -- same selector returned
 <db_selector>:add_distinct_on(
   expression                    -- expression as passed to "assemble_command"
@@ -649,6 +665,9 @@
 
 function selector_metatable:__tostring()
   local parts = {sep = " "}
+  if #self._with > 0 then
+    add(parts, {"WITH RECURSIVE $", self._with})
+  end
   add(parts, "SELECT")
   if self._distinct then
     add(parts, "DISTINCT")