See Also: DF_FILE_PRIMARY_INDEX, DF_FILE_RECORD_IDENTITY
Specifies if the table contains a Recnum column.
Table
All Drivers
Boolean, permanent
Read / Write for the DataFlex SQL Drivers (SQL Server, DB2 and ODBC)
Read Only for DataFlex and Pervasive.SQL
For other drivers, refer to the driver's documentation
True, False
The DF_FILE_RECNUM_TABLE attribute determines if Recnum is used to define a table's record identity. Typically this attribute is used to determine if the Recnum column can be used for a table.
When DF_FILE_RECUM_TABLE is true, records in the table are identified by a single numeric column. This may be a logical or physical column. In either case the table will have a column with number 0 that is called recnum. This column can be accessed via Table.Recnum. A Recnum column is treated in a special way. If a value is moved to the recnum column, the buffer is made inactive (the DF_FILE_STATUS attribute is set to DF_FILE_INACTIVE). If a buffer is inactive a save operation on that buffer will create a new record.
When DF_FILE_RECNUM_TABLE is false, records in the table are identified by one or more columns of any type. The identifying columns are defined by setting the DF_FILE_PRIMARY_INDEX attribute.
A recnum table’s column numbers start at 0 (zero) where a standard table’s column numbers start at 1. Attempting to access column 0 (zero) of a standard table will result in an error message (DFERR_FIELD_NUMBER_RANGE).
Note that this attribute determines how the table handles unique identities. It does not determine whether the programming interface will use a Recnum or RowId style programming interface. All table types can and should be accessed using the RowId programming interface. If the RowId programming interface is used, you will not need to know if Recnum is supported, hence, you should rarely need to use this attribute.
This attribute can only be set inside a Structure_Start ... Structure_End operation. The DataFlex SQL Drivers store the value of the attribute in the intermediate file under the Recnum_Table keyword.
The Embedded Database only supports recnum tables, in other words, the value of DF_FILE_RECNUM_TABLE is always true for an Embedded Database table.
The DataFlex Pervasive.SQL Driver only supports recnum tables, in other words, the value of DF_FILE_RECNUM_TABLE is always true for a Pervasive.SQL table.
The DataFlex SQL Drivers support both recnum and standard tables, starting at version 4. Older versions of these drivers only support recnum tables.
Procedure ShowRecnumTables
Handle hTable
String sTable
Boolean bRecnumTable
Move 0 To hTable
Repeat
Get_Attribute DF_FILE_NEXT_USED Of hTable To hTable
If (hTable > 0) Begin
Open hTable
Get_Attribute DF_FILE_LOGICAL_NAME Of hTable To sTable
Get_Attribute DF_FILE_RECNUM_TABLE Of hTable To bRecnumTable
Showln sTable " -- " (If(bRecnumTable, "RECNUM", "STANDARD")) " table"
Close hTable
End
Until (hTable = 0)
End_Procedure
The sample procedure above shows all tables in the filelist and of every table it shows if it is recnum or a standard table.
Procedure ShowRecord Handle hTable
Boolean bRecnumTable
Integer iNumColumns iColumn iStart
String sValue
Get_Attribute DF_FILE_RECNUM_TABLE Of hTable To bRecnumTable
If (bRecnumTable) ;
Move 0 To iStart
Else ;
Move 1 To iStart
Get_Attribute DF_FILE_NUMBER_FIELDS Of hTable To iNumColumns
For iColumn From iStart To iNumColumns
Get_Field_Value hTable iColumn To sValue
If (iColumn > iStart) ;
Show ", "
Show (Trim(sValue))
Loop
Showln
End_Procedure
The sample procedure above shows the contents of a record of a given table. If this is a recnum table it shows the value of the recnum column.
Procedure CreateClockTable
Handle hTable hoWorkspace
String sPath sOrigFolder
Integer iColumn iIndex
//*** Make sure int file comes in first folder of datapath by
//*** making that folder current
Get phoWorkspace Of ghoApplication To hoWorkspace
Get psDataPath Of hoWorkspace To sPath
Get PathAtIndex Of hoWorkspace sPath 1 To sPath
Get_Current_Directory To sOrigFolder
Set_Directory sPath
//*** Create a SQL Server table to store clock in/out times
//*** of employees
Move 0 To hTable
Structure_Start hTable "MSSQLDRV"
Set_Attribute DF_FILE_PHYSICAL_NAME Of hTable To "Clock.int"
Set_Attribute DF_FILE_RECNUM_TABLE Of hTable To False
Set_Attribute DF_FILE_LOGIN Of hTable To ;
"SERVER=(local);Trusted_Connection=yes;DATABASE=Northwind"
Set_Attribute DF_FILE_TABLE_NAME Of hTable To "Clock"
Set_Attribute DF_FILE_USE_DUMMY_ZERO_DATE Of hTable To True
Create_Field hTable At iColumn
Set_Attribute DF_FIELD_NAME Of hTable iColumn To "EmployeeID"
Set_Attribute DF_FIELD_TYPE Of hTable iColumn To DF_BCD
Set_Attribute DF_FIELD_LENGTH Of hTable iColumn To 10
Set_Attribute DF_FIELD_NATIVE_TYPE Of hTable iColumn To SQL_INTEGER
Move 0 To iColumn
Create_Field hTable At iColumn
Set_Attribute DF_FIELD_NAME Of hTable iColumn To "ClockInTime"
Set_Attribute DF_FIELD_TYPE Of hTable iColumn To DF_DATE
Move 0 To iColumn
Create_Field hTable At iColumn
Set_Attribute DF_FIELD_NAME Of hTable iColumn To "ClockOutTime"
Set_Attribute DF_FIELD_TYPE Of hTable iColumn To DF_DATE
Move 0 To iIndex
Create_Index hTable At iIndex
Set_Attribute DF_INDEX_NUMBER_SEGMENTS Of hTable iIndex To 3
Set_Attribute DF_INDEX_SEGMENT_FIELD Of hTable iIndex 1 To 1
Set_Attribute DF_INDEX_SEGMENT_FIELD Of hTable iIndex 2 To 2
Set_Attribute DF_INDEX_SEGMENT_DIRECTION Of hTable iIndex 2 To DF_DESCENDING
Set_Attribute DF_INDEX_SEGMENT_FIELD Of hTable iIndex 3 To 3
Set_Attribute DF_FILE_PRIMARY_INDEX Of hTable To iIndex
Set_Attribute DF_INDEX_NAME Of hTable iIndex To "ClockPK"
Structure_End hTable
//*** Reset current working folder to original value
Set_Directory sOrigFolder
//*** Add to filelist and generate fd
Move 0 To hTable
Get_Attribute DF_FILE_NEXT_EMPTY Of hTable To hTable
If (hTable > 0) Begin
Set_Attribute DF_FILE_ROOT_NAME Of hTable To "MSSQLDRV:Clock"
Set_Attribute DF_FILE_DISPLAY_NAME Of hTable To "Clock sample table"
Set_Attribute DF_FILE_LOGICAL_NAME Of hTable To "Clock"
Open hTable
Get psDDSRCPath Of hoWorkspace To sPath
Get PathAtIndex Of hoWorkspace sPath 1 To sPath
If (Right(sPath, 1) <> Sysconf(Sysconf_Dir_Separator)) ;
Move (sPath - Sysconf(Sysconf_Dir_Separator)) To sPath
Move (sPath - "Clock.fd") To sPath
Output_Aux_File DF_AUX_FILE_FD For hTable To sPath
Close hTable
End
End_Procedure
The sample procedure above creates a standard table called Clock with one unique index that is set to be the primary index.