8aee8d
@@ -8539,7 +8539,17 @@
private String getPrimaryKeyConstraintName(String db_name, String tbl_name) thro
     final String parent_tbl_name = parent_tbl_name_input;
     final String foreign_db_name = foreign_db_name_input;
     final String foreign_tbl_name = foreign_tbl_name_input;
-    return new GetListHelper<SQLForeignKey>(foreign_db_name, foreign_tbl_name, allowSql, allowJdo) {
+    final String db_name;
+    final String tbl_name;
+    if (foreign_tbl_name == null) {
+      // The FK table name might be null if we are retrieving the constraint from the PK side
+      db_name = parent_db_name_input;
+      tbl_name = parent_tbl_name_input;
+    } else {
+      db_name = foreign_db_name_input;
+      tbl_name = foreign_tbl_name_input;
+    }
+    return new GetListHelper<SQLForeignKey>(db_name, tbl_name, allowSql, allowJdo) {
 
       @Override
       protected List<SQLForeignKey> getSqlResult(GetHelper<List<SQLForeignKey>> ctx) throws MetaException {
