}
	inferTypeAsString(v1)
	s, ok := v1.ToString()
	if !ok {
		err := fmt.Errorf("Incorrect argument type passed to %s", sqlFnSubstring)
		return nil, errIncorrectSQLFunctionArgumentType(err)
	}

	// Assemble other arguments
	arg2, arg3 := e.From, e.For
	// Check if the second form of substring is being used
	if e.From == nil {
		arg2, arg3 = e.Arg2, e.Arg3
	}

	// Evaluate the FROM argument