Syntax for SQL Statements used with SCCM Data Sources

[LonLandry1]

I have a requirement to customize the SQL statements for SCCM Data Sources.

Is there documentation that explains syntax allowed or at least mentions limitations?

The statement below does not seem to work with ServiceNow. (While the OoB works)

SELECT v_GS_COMPUTER_SYSTEM.Name0 AS computer_name,
v_GS_COMPUTER_SYSTEM.domain0 AS domain,
v_GS_COMPUTER_SYSTEM.Model0 AS model,
v_GS_COMPUTER_SYSTEM.Manufacturer0 AS manufacturer,
v_GS_COMPUTER_SYSTEM.ResourceID,
NULLIF(v_GS_SYSTEM_CONSOLE_USAGE.TopConsoleUser0, '') AS assigned_to,
v_GS_COMPUTER_SYSTEM.NumberOfProcessors0 AS processor_count,
v_GS_SYSTEM.SystemRole0 AS system_role,
v_GS_OPERATING_SYSTEM.Caption0 AS os_caption,
v_GS_OPERATING_SYSTEM.Version0 AS os_version,
v_GS_SYSTEM_ENCLOSURE.ChassisTypes0 AS chassis_type,
NULLIF(v_GS_PC_BIOS.SerialNumber0, '') AS bios_serial_number,
NULLIF(v_GS_COMPUTER_SYSTEM_PRODUCT.IdentifyingNumber0, '') AS system_serial_number,
NULLIF(v_GS_COMPUTER_SYSTEM_PRODUCT.UUID0, '') AS uuid_serial_number,
NULLIF(v_GS_SYSTEM_ENCLOSURE.SerialNumber0, '') AS chassis_serial_number,
NULLIF(v_GS_SYSTEM_ENCLOSURE.SMBIOSAssetTag0, '') AS asset_tag,
WorkstationStatus_DATA.TimeKey AS u_computertimekey,
v_GS_OPERATING_SYSTEM.TimeStamp AS os_timestamp,
v_R_System.Creation_Date0 AS assigned_date
FROM v_GS_COMPUTER_SYSTEM
LEFT JOIN WorkstationStatus_DATA
ON v_GS_COMPUTER_SYSTEM.ResourceID = WorkstationStatus_DATA.MachineID
LEFT JOIN v_GS_SYSTEM
ON v_GS_COMPUTER_SYSTEM.ResourceID = v_GS_SYSTEM.ResourceID
LEFT JOIN v_GS_PC_BIOS
ON v_GS_COMPUTER_SYSTEM.ResourceID = v_GS_PC_BIOS.ResourceID
LEFT JOIN v_GS_OPERATING_SYSTEM
ON v_GS_COMPUTER_SYSTEM.ResourceID = v_GS_OPERATING_SYSTEM.ResourceID
LEFT JOIN v_GS_COMPUTER_SYSTEM_PRODUCT
ON v_GS_COMPUTER_SYSTEM.ResourceID = v_GS_COMPUTER_SYSTEM_PRODUCT.ResourceID
LEFT JOIN v_GS_SYSTEM_ENCLOSURE
ON v_GS_COMPUTER_SYSTEM.ResourceID = v_GS_SYSTEM_ENCLOSURE.ResourceID
LEFT JOIN v_GS_BASEBOARD
ON v_GS_COMPUTER_SYSTEM.ResourceID = v_GS_BASEBOARD.ResourceID
LEFT JOIN v_GS_SYSTEM_CONSOLE_USAGE
ON v_GS_COMPUTER_SYSTEM.ResourceID = v_GS_SYSTEM_CONSOLE_USAGE.ResourceID
LEFT JOIN v_R_System
ON v_GS_COMPUTER_SYSTEM.ResourceID = v_R_System.ResourceID;