Index: cdr/cdr_adaptive_odbc.c
===================================================================
--- cdr/cdr_adaptive_odbc.c	(revision 286024)
+++ cdr/cdr_adaptive_odbc.c	(working copy)
@@ -65,6 +65,7 @@
 	SQLSMALLINT nullable;
 	SQLINTEGER octetlen;
 	AST_LIST_ENTRY(columns) list;
+	unsigned int negatefiltervalue:1;
 };
 
 struct tables {
@@ -163,10 +164,17 @@
 		/* Check for filters first */
 		for (var = ast_variable_browse(cfg, catg); var; var = var->next) {
 			if (strncmp(var->name, "filter", 6) == 0) {
+				int negate = 0;
 				char *cdrvar = ast_strdupa(var->name + 6);
 				cdrvar = ast_strip(cdrvar);
-				ast_verb(3, "Found filter %s for cdr variable %s in %s@%s\n", var->value, cdrvar, tableptr->table, tableptr->connection);
+				if (cdrvar[strlen(cdrvar) - 1] == '!') {
+					negate = 1;
+					cdrvar[strlen(cdrvar) - 1] = '\0';
+					ast_trim_blanks(cdrvar);
+				}
 
+				ast_verb(3, "Found filter %s'%s' for cdr variable %s in %s@%s\n", negate ? "!" : "", var->value, cdrvar, tableptr->table, tableptr->connection);
+
 				entry = ast_calloc(sizeof(char), sizeof(*entry) + strlen(cdrvar) + 1 + strlen(var->value) + 1);
 				if (!entry) {
 					ast_log(LOG_ERROR, "Out of memory creating filter entry for CDR variable '%s' in table '%s' on connection '%s'\n", cdrvar, table, connection);
@@ -180,6 +188,7 @@
 				entry->filtervalue = (char *)entry + sizeof(*entry) + strlen(cdrvar) + 1;
 				strcpy(entry->cdrname, cdrvar);
 				strcpy(entry->filtervalue, var->value);
+				entry->negatefiltervalue = negate;
 
 				AST_LIST_INSERT_TAIL(&(tableptr->columns), entry, list);
 			}
@@ -403,10 +412,11 @@
 				 * is very specifically NOT ast_strlen_zero(), because the filter
 				 * could legitimately specify that the field is blank, which is
 				 * different from the field being unspecified (NULL). */
-				if (entry->filtervalue && strcasecmp(colptr, entry->filtervalue) != 0) {
+				if ((entry->filtervalue && !entry->negatefiltervalue && strcasecmp(colptr, entry->filtervalue) != 0) ||
+					(entry->filtervalue && entry->negatefiltervalue && strcasecmp(colptr, entry->filtervalue) == 0)) {
 					ast_verb(4, "CDR column '%s' with value '%s' does not match filter of"
-						" '%s'.  Cancelling this CDR.\n",
-						entry->cdrname, colptr, entry->filtervalue);
+						" %s'%s'.  Cancelling this CDR.\n",
+						entry->cdrname, colptr, entry->negatefiltervalue ? "!" : "", entry->filtervalue);
 					goto early_release;
 				}