1.1 --- a/libraries/mondelefant/mondelefant.lua	Thu Dec 10 12:00:00 2009 +0100
     1.2 +++ b/libraries/mondelefant/mondelefant.lua	Fri Dec 25 12:00:00 2009 +0100
     1.3 @@ -62,17 +62,15 @@
     1.4    self._distinct = false
     1.5    self._distinct_on = {sep = ", ", expression}
     1.6    self._from = { sep = " " }
     1.7 -  self._where = { sep = " AND " }
     1.8 +  self._where = { sep = ") AND (" }
     1.9    self._group_by = { sep = ", " }
    1.10 -  self._having = { sep = " AND " }
    1.11 +  self._having = { sep = ") AND (" }
    1.12    self._combine = { sep = " " }
    1.13    self._order_by = { sep = ", " }
    1.14    self._limit = nil
    1.15    self._offset = nil
    1.16 -  --[[
    1.17 -  self._lock = nil
    1.18 -  self._lock_tables = { sep = ", " }
    1.19 -  --]]
    1.20 +  self._read_lock = { sep = ", " }
    1.21 +  self._write_lock = { sep = ", " }
    1.22    self._class = nil
    1.23    self._attach = nil
    1.24    return self
    1.25 @@ -193,6 +191,26 @@
    1.26    return self
    1.27  end
    1.28  
    1.29 +function selector_prototype:for_share()
    1.30 +  self._read_lock.all = true
    1.31 +  return self
    1.32 +end
    1.33 +
    1.34 +function selector_prototype:for_share_of(expression)
    1.35 +  add(self._read_lock, expression)
    1.36 +  return self
    1.37 +end
    1.38 +
    1.39 +function selector_prototype:for_update()
    1.40 +  self._write_lock.all = true
    1.41 +  return self
    1.42 +end
    1.43 +
    1.44 +function selector_prototype:for_update_of(expression)
    1.45 +  add(self._write_lock, expression)
    1.46 +  return self
    1.47 +end
    1.48 +
    1.49  function selector_prototype:reset_fields()
    1.50    for idx in ipairs(self._fields) do
    1.51      self._fields[idx] = nil
    1.52 @@ -324,13 +342,13 @@
    1.53    if #self._mode == "empty_list" then
    1.54      add(parts, "WHERE FALSE")
    1.55    elseif #self._where > 0 then
    1.56 -    add(parts, {"WHERE $", self._where})
    1.57 +    add(parts, {"WHERE ($)", self._where})
    1.58    end
    1.59    if #self._group_by > 0 then
    1.60      add(parts, {"GROUP BY $", self._group_by})
    1.61    end
    1.62    if #self._having > 0 then
    1.63 -    add(parts, {"HAVING $", self._having})
    1.64 +    add(parts, {"HAVING ($)", self._having})
    1.65    end
    1.66    for i, v in ipairs(self._combine) do
    1.67      add(parts, v)
    1.68 @@ -348,6 +366,18 @@
    1.69    if self._offset then
    1.70      add(parts, "OFFSET " .. self._offset)
    1.71    end
    1.72 +  if self._write_lock.all then
    1.73 +    add(parts, "FOR UPDATE")
    1.74 +  else
    1.75 +    if self._read_lock.all then
    1.76 +      add(parts, "FOR SHARE")
    1.77 +    elseif #self._read_lock > 0 then
    1.78 +      add(parts, {"FOR SHARE OF $", self._read_lock})
    1.79 +    end
    1.80 +    if #self._write_lock > 0 then
    1.81 +      add(parts, {"FOR UPDATE OF $", self._write_lock})
    1.82 +    end
    1.83 +  end
    1.84    return self._db_conn:assemble_command{"$", parts}
    1.85  end
    1.86  
    1.87 @@ -390,6 +420,18 @@
    1.88    end
    1.89  end
    1.90  
    1.91 +-- NOTE: This function caches the result!
    1.92 +function selector_prototype:count()
    1.93 +  if not self._count then
    1.94 +    local count_selector = self:get_db_conn():new_selector()
    1.95 +    count_selector:add_field('count(1)')
    1.96 +    count_selector:add_from(self)
    1.97 +    count_selector:single_object_mode()
    1.98 +    self._count = count_selector:exec().count
    1.99 +  end
   1.100 +  return self._count
   1.101 +end
   1.102 +
   1.103  
   1.104  
   1.105  -----------------