diff -uNr sqlite-3.4.1/src/func.c.orig sqlite-3.4.1/src/func.c
--- sqlite-3.4.1/src/func.c.orig	2007-06-28 12:46:19.000000000 +0000
+++ sqlite-3.4.1/src/func.c	2007-07-23 11:39:52.000000000 +0000
@@ -150,6 +150,31 @@
 }
 
 /*
+** Implementation of the sign() function
+*/
+static void signFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
+  assert( argc==1 );
+  switch( sqlite3_value_type(argv[0]) ){
+    case SQLITE_INTEGER: {
+      i64 iVal = sqlite3_value_int64(argv[0]);
+      iVal = (iVal > 0)? 1 : (iVal < 0)? -1 : 0;
+      sqlite3_result_int64(context, iVal);
+      break;
+    }
+    case SQLITE_NULL: {
+      sqlite3_result_null(context);
+      break;
+    }
+    default: {
+      double rVal = sqlite3_value_double(argv[0]);
+      rVal = (rVal > 0)? 1.0 : (rVal < 0)? -1.0 : 0;
+      sqlite3_result_double(context, rVal);
+      break;
+    }
+  }
+}
+
+/*
 ** Implementation of the substr() function.
 **
 ** substr(x,p1,p2)  returns p2 characters of x[] beginning with p1.
@@ -1315,6 +1340,7 @@
     FUNCTION(substr,             2, 0, 0, substrFunc       ),
     FUNCTION(substr,             3, 0, 0, substrFunc       ),
     FUNCTION(abs,                1, 0, 0, absFunc          ),
+    FUNCTION(sign,               1, 0, 0, signFunc         ),
 #ifndef SQLITE_OMIT_FLOATING_POINT
     FUNCTION(round,              1, 0, 0, roundFunc        ),
     FUNCTION(round,              2, 0, 0, roundFunc        ),