If the record does not exist, "#form.table.fieldx#" returns the same = "#form.table.field#". Use the ternary operator ( condition ? exprIfTrue : exprIfFalse ) to check and set to NULL if the return value matches the origin hash variable (if used in BeanShell or Javascript).
If record exist but fieldx is empty, "#form.table.fieldx#" returns empty = "".
If record exist and fieldx has value "abc", "#form.table.fieldx#" returns the value = "abc".
Hash Variable Features In Joget DX Community Edition