Jake said:

You could try a CAST on the value column - I'm assuming that's the one
that
comes back as a string value?

Yup.

Thank you very much for that. It's not working properly in that I'm getting
an error:

"Incorrect column expression: 'CAST(value AS Decimal(20,10))'"

(I also tried casting it as float4 and float8 with the same error message.

But that's enough for me to know where to start to look.

much appreciated,
Christopher