diff --git a/packages/fcl-db/src/sqldb/mysql/mysqlconn.inc b/packages/fcl-db/src/sqldb/mysql/mysqlconn.inc
index 224524c053..4665d55785 100644
--- a/packages/fcl-db/src/sqldb/mysql/mysqlconn.inc
+++ b/packages/fcl-db/src/sqldb/mysql/mysqlconn.inc
@@ -717,6 +717,7 @@ function TConnectionName.MySQLWriteData(AType: enum_field_types;ASize: Integer;
 
 var
   VI: Integer;
+  VL: LargeInt;
   VS: Smallint;
   VF: Double;
   VC: Currency;
@@ -749,10 +750,10 @@ begin
     FIELD_TYPE_LONGLONG:
       begin
       if (Src<>'') then
-        VI := StrToInt64(Src)
+        VL := StrToInt64(Src)
       else
-        VI := 0;
-      Move(VI, Dest^, SizeOf(LargeInt));
+        VL := 0;
+      Move(VL, Dest^, SizeOf(LargeInt));
       end;
 {$ifdef mysql50}
     FIELD_TYPE_NEWDECIMAL,
diff --git a/packages/fcl-db/tests/sqldbtoolsunit.pas b/packages/fcl-db/tests/sqldbtoolsunit.pas
index f64959dbb8..e2771d1048 100644
--- a/packages/fcl-db/tests/sqldbtoolsunit.pas
+++ b/packages/fcl-db/tests/sqldbtoolsunit.pas
@@ -103,6 +103,8 @@ begin
   if SQLDbType = MYSQL40 then Fconnection := tMySQL40Connection.Create(nil);
   if SQLDbType = MYSQL41 then Fconnection := tMySQL41Connection.Create(nil);
   if SQLDbType = MYSQL50 then Fconnection := tMySQL50Connection.Create(nil);
+  if SQLDbType in MySQLdbTypes then
+    FieldtypeDefinitions[ftLargeint] := 'BIGINT';
   if SQLDbType = sqlite3 then
     begin
     Fconnection := TSQLite3Connection.Create(nil);