Hi @TeophelusJohannes18 

If it’s your custom field - I’d try first to change the setter:

        public string Field
        {
            get
            {
                return Field;
            }

            set
            {
                Field = value.ToUpper();
            }
        }

For standard field - you can create a Graph Extension, define an event handler (FieldUpdating) and change the case:

        protected virtual void _(Events.FieldUpdating<YourDac.field> e)
        {
            if (!(e.NewValue is string newValue))
                return;

            e.NewValue = newValue.ToUpper();
        }

You could also go with the trigger in the database, but I’d say doing it in code is more preferable.

I can also see different solution for the similar question at the Stack Overflow, maybe you like it more.

Hi @TeophelusJohannes18,
You can use the InputMask property in your DAC declaration of the field to ensure that data is entered according to your desired format

You can use it lIke 

>PXDBString(6, IsKey = true, InputMask = ">CCCCCC")]

hope, it helps!

[PXDBString(6, IsKey = true, InputMask = ">CCCCCC")]

This

Thanks a lot, guys. It worked for me