See Also: Overview of the DataFlex Database Update Framework
Hierarchy
cObject
---cDbUpdateHandler
------cDbUpdateVersion
------cDbUpdateFunctionLibrary
------cDbUpdateLogFile
------cDbUpdateUserCount
------cSQLConnectionHandler
---------cSQLConnectionIniFile
---------cDbUpdateDatabaseDriver
Library: Windows Application Class Library
Package: cDbUpdateVersion.pkg
Description
This is a child class of the cDbUpdateHandler class.
Put an object of this class inside the cDbUpdateHandler object. Set the pnVersionNumber to a consecutive database version number. Place your update code in the OnUpdate event to alter the database.
Add one cDbUpdateVersion object for each update of the database and specify its database version by setting the pnVersionNumber property.
To aid when adding database update code for the OnUpdate event the function library cDbUpdateFunctionLibrary has been imported to the cDbUpdateHandler class, thus making all those functions easily accessible from within the OnUpdate event. The library contains a whole range of functions for easy manipulation of the database and it can be expanded by the developer if needed.
See cDbUpdateHandler for more info about the container object.
See cDatabaseFunctionsLibrary for more info about all functions available to this class, including specialized SQL functions.
Important
The order of each cDbUpdateVersion objects is important and the pnVersionNumber for each and one of them *must* be consecutive! So a cDbUpdateVersion object with a pnVersionNumber = 1.5 must come after (below) a cDbUpdateVersion object with a pnVersionNumber = 1.4 setting, or the "pnVersionNumber = 1.4" object's Update code won't get executed.
Note
When converting embedded tables to SQL there are two different interfaces; one geared at being more Object Oriented and the other is a function that takes on a series of parameters to do the same thing. Compare below the 1.0 example that uses the ApiTableConvertToSQL function and also sets a series of object properties - versus - the 1.1 sample that uses the ApiTableConvertToSQL_Ex (Extended) function to do it all in one line of code. The reason here being that if e.g. the DB2 database is used there are a lot of more info that is needed for the conversion process to succeed.
Sample
// These are needed to keep the compiler happy;
Declare_Datafile Customer
Declare_Datafile Invt
Declare_Datafile OrderDtl
Declare_Datafile OrderHea
Declare_Datafile OrdSys
Declare_Datafile SalesP
Declare_Datafile Users
Declare_Datafile Vendor
Object oDbUpdateHandler is an cDbUpdateHandler
Set Data_File_Field to File_Field DbVersion.DatabaseVersion
Object oUpdateVersion1 is a cDbUpdateVersion
Set pnVersionNumber to 1
Set pbUseConnectionID to True
Set pbCopyData to True
Set pbRecnum to True
Set pbToANSI to True
// If the psDriverID is not set it is read from the SQLConnections.ini file.
// Add update code to the OnUpdate event
Procedure OnUpdate
Boolean bOK
Get ApiTableConvertToSQL Invt.File_Number to bOK
Get ApiTableConvertToSQL OrderHea.File_Number to bOK
Get ApiTableConvertToSQL OrderDtl.File_Number to bOK
Get ApiTableConvertToSQL OrdSys.File_Number to bOK
Get ApiTableConvertToSQL SalesP.File_Number to bOK
Get ApiTableConvertToSQL Vendor.File_Number to bOK
End_Procedure
End_Object
Object oDbUpdateVersion2 is a cDbUpdateVersion
Set pnVersionNumber to 2
Procedure OnUpdate
Boolean bOK
// Alternate table conversion function that instead of setting properties like in
// above passes a series of parameters.
Get ApiTableConvertToSQL_Ex Users.File_Number MSSQLDRV_ID True True True True to bOK
Get SQLColumnRename Customer.File_Number "Purchases" "YearlyPurchases" MSSQLDRV_ID to bOK
Get SQLColumnAdd Customer.File_Number "IsPrinted" DF_BCD_DUF 4 0 True "1" to bOK
End_Procedure
End_Object
Object oUpdateVersion3 is a cDbUpdateVersion
Set pnVersionNumber to 3
Use VersionUpdate3.pkg
:
End_Object
End_Object
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