diff --git a/src/rdb_by_api_link.jl b/src/rdb_by_api_link.jl
index dceaa1e..4a1d726 100644
--- a/src/rdb_by_api_link.jl
+++ b/src/rdb_by_api_link.jl
@@ -330,10 +330,10 @@ function rdb_by_api_link(
             )
 
             if suffix != ""
-                DBdata[Symbol(addcol)] = ifelse.(
-                    isa.(DBdata[Symbol(newcol)], Missing),
-                    DBdata[Symbol(addcol)],
-                    DBdata[Symbol(newcol)]
+                DBdata[selectop, Symbol(addcol)] = ifelse.(
+                    isa.(DBdata[selectop, Symbol(newcol)], Missing),
+                    DBdata[selectop, Symbol(addcol)],
+                    DBdata[selectop, Symbol(newcol)]
                 )
                 df_delete_col!(DBdata, Symbol(newcol))
             end
diff --git a/src/utils.jl b/src/utils.jl
index 40b6d43..3bec7ac 100644
--- a/src/utils.jl
+++ b/src/utils.jl
@@ -468,11 +468,13 @@ end
 
 #-------------------------------------------------------------------------------
 # remove_provider
+remove_provider!(x::Nothing) = nothing
 function remove_provider!(x::Array)
     map(x) do u
         u[1] = replace(u[1], r".*/" => "")
         u
     end
+    nothing
 end
 
 #-------------------------------------------------------------------------------