The LA Fox Developer Newsletter

June 2000

ADO Jumpstart (Con’t from page 3)

Categories RELATE ‘CategorylD’ TO ‘CategorytD’) AS

categories,((SELECT * FROM “dbo”.”Suppllers”} AS Suppliers

RELATE ‘SupplierlD’ TO ‘SupplieriD’) AS Suppliers) AS Products

RELATE ‘ProductiD’ TO ‘ProductiD’) AS Products) AS OrderDetails

RELATE ‘OrderiD’ TO ‘OrderiD’) AS OrderDetails,(( SHAPE (SELECT *

FROM “dbo”.”Emptoyees”} AS Employees APPEND (( SHAPE

(SELECT * FROM “dbo”.”EmployeeTerritories”} AS

Employee Territories APPEND (( SHAPE (SELECT * FROM

“dbo”.”Territories”) AS Territories APPEND ((SELECT * FROM

“dbo”.”Region”} AS Region RELATE ‘RegioniD’ TO ‘RegioniD’) AS

Region) AS Territories RELATE ‘TerritorylD’ TO ‘TerritorylD’) AS

Territories) AS EmployeeTerritories RELATE ‘EmployeelD’ TO

‘EmployeelD’) AS EmployeeTerritories) AS Employees RELATE

‘EmployeelD’ TO ‘EmployeelD’) AS Employees,((SELECT * FROM

“dbo”.”Shippers”) AS Shippers RELATE ‘ShipVia’ TO ‘ShipperlD’) AS

Shippers) AS Orders RELATE ‘CustomerlD’ TO ‘CustomerlD’) AS

Orders

This is just about as complicated as it gets. Nobody in their

right mind would want to hammer this code out manually.

Fortunately, there is a visual way to build this code. The

DataEnvironment designer that ships with Visual Basic allows

you to visually design ADO connections, recordsets, and

hierarchical recordsets. The following illustrates how this

hierarchical recordset appears in the designer:

The extensive Shape syntax can be copied and pasted into

Visual FoxPro, or any other environment that can host ADO.

For complete details on how to use the DataEnvironment

designer, consult the Visual Basic documentation on the MSDN

CDs that ship with Visual Studio.

The following Visual FoxPro code traverses the hierarchical

recordset and displays the data:

#lnclude adovfp.h

oRecordset = createObject(”adodb.recordset”)

oConnection = CreateObject(”adodb.connection”)

(Con’t, page 5)

Undocumented (Con’t from page 3)

CHANGEO

I believe this function was used as part of dBaselV’s transaction

system. This function determines whether or not a record had

Changed or is a “dirty” record. Returns a .F. in VFP. This is

documented in the latest HackersGuide...

COMPLETED()

This function is for compatibility with dBaselV. dBaselV prob-

ably used it for the same purpose for which we use the

TABLEUPDATEO function. This function returns a .F. in VFP.

This is documented in the latest HackersGuide...

FIXED(number)

This function is for compatibility with dBaselV. What it does, I

don’t know nor remember. There is actually error checking for

this command. Enter FIXEDO without a parameter and VFP will

disallow it. Pass it some sort of number and VFP promptly

returns it. I don’t see much value in that...

FLOAT(number)

This function is for compatibility with dBaselV. What it does, I

don’t know nor remember. There is actually error checking for

this command. Enter FLOAT() without a parameter and VFP will

disallow it. Pass it some sort of number and VFP promptly

returns it. I don’t see much value in that...

ID()

This is supposed to return the same thing as SYS(O). If I

remember correctly, this function came in as part of the addi-

tional Foxpro 2.6 command set, trying to be more compatibile

with dBase. That’s how we got PCOUNTO, which is a better

function than PARAMETERSO. Anyway, the HackersGuide

goes into some detail with this command and states that on

some machines that the SYS(O) is not returned.

ISMARKED()

This function now returns an error in VFP. Foxpro used to

accept this function and not generate an error. For some

reason, the developers of VFP made it a point to take this

command out of the keyword set. Why I don’t know. This is

documented in the latest HackersGuide...

LKSYSO

This function now returns an error in VFP. Foxpro used to

accept this function and not generate an error. Since VFP is

less usable than FoxPro 2.6 for converting old dBase IV pro-

grams this function has been taken out of the keyword set. It’s

an unsupported dBase IV function that is used in dBase IV to

query information about who locked a record, since what time it

has been locked, etc. in dBase IV this function is not Y2K-

compliant. In fact, Foxpro used to generate an error if you didn’t

pass the right amount of arguments. But when you passed one

number to the Lksys function, it returned “Function Not Imple-

mented.”

This was documented in the latest HackersGuide.

(Con’t, page 5)

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