APEX_JSON.WRITE Tips

• For null case

Use: APEX_JSON.write('P_INVOICE_TRACKING', '', true);

Result: "P_INVOICE_TRACKING":null 

• For Escaping "& /" character 

Use: APEX_JSON.write_raw('P_INVOICE_NUMBER', '"'||r_header.sppd_code||'"');

Result: "P_INVOICE_NUMBER":"0134/XYZ/084/RS/2021"