--- a/sql.urs	Tue Jun 14 08:55:15 2011 -0400
+++ b/sql.urs	Sun Dec 11 14:04:34 2011 -0500
@@ -15,3 +15,19 @@
                => folder fs
                -> sql_exp [tn1 = ofs1 ++ fs, tn2 = ofs2 ++ fs] [] [] bool
 (* Declare equality of same-named columns from two tables. *)
+
+val insertIfMissing : keyCols ::: {Type} -> otherCols ::: {Type} -> otherKeys ::: {{Unit}}
+                      -> [keyCols ~ otherCols] => [[Pkey] ~ otherKeys]
+                      => sql_table (keyCols ++ otherCols) ([Pkey = map (fn _ => ()) keyCols] ++ otherKeys)
+                      -> $(keyCols ++ otherCols)
+                      -> folder keyCols -> $(map sql_injectable keyCols)
+                      -> folder otherCols -> $(map sql_injectable otherCols)
+                      -> transaction bool
+(* Insert a row into an SQL table if its key isn't already present, returning [False] iff the key was already present *)
+
+val deleteByKey : keyCols ::: {Type} -> otherCols ::: {Type} -> otherKeys ::: {{Unit}}
+                  -> [keyCols ~ otherCols] => [[Pkey] ~ otherKeys]
+                  => sql_table (keyCols ++ otherCols) ([Pkey = map (fn _ => ()) keyCols] ++ otherKeys)
+                  -> $keyCols -> folder keyCols -> $(map sql_injectable keyCols)
+                  -> transaction {}
+(* Delete a row from a table by matching its primary key against a given record. *)