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DbServer.OrderInfo Method

Return and optionally change information about orders and index files.

Namespace:  VO
Assembly:  VORDDClasses (in VORDDClasses.dll) Version: 2.5
Syntax
 VIRTUAL METHOD OrderInfo(
	kOrderInfoType AS USUAL,
	oFSIndex AS USUAL,
	uOrder AS USUAL,
	uOrdVal AS USUAL
) AS USUAL

Parameters

kOrderInfoType
Type: Usual
Specifies the type of information.  The constants are listed below.  Note, however, that not all constants are supported for all RDDs.
Important!  DBOI_USER is a constant that returns the minimum value that third-party RDD developers can use for defining new <kInfoType> parameters.  Values less than DBOI_USER are reserved for VO development.
oFSIndex
Type: Usual
The name of an index file, including an optional drive and directory (no extension should be specified).  Use this argument with <cOrder> to remove ambiguity when there are two or more orders with the same name in different index files. If <oFSIndex> is not open by the current process, a runtime error is raised.
uOrder
Type: Usual
The name of the order about which you want to obtain information or a number representing its position in the order list.  (For single-order index files, the order name is the eight-letter index file name.)  Using the order name is the preferred method since the position may be difficult to determine using multiple-order index files.  Invalid values are ignored. If no index file or order is specified, the controlling order is assumed.
uOrdVal
Type: Usual
If specified, this parameter is used to change the value of a setting.  The data type (and whether <uOrdVal> can be specified), depends on the <kInfoType> constant and is documented in the Constants section below.

Return Value

Type: Usual
If <uNewSetting> is not specified, DBServer:OrderInfo() returns the current setting.  If <uNewSetting> is specified, the previous setting is returned.
Remarks
ConstantDescription
DBOI_CONDITIONReturns the for condition of the specified order as a string.
DBOI_CUSTOMReturns and optionally sets the logical flag indicating whether the specified order is custom built (for RDDs that support custom built orders).  Note that although you can turn the custom built flag on for a standard order by specifying TRUE for the <uNewSetting> argument, you cannot turn a custom built order into a standard order.  Specifying FALSE for <uNewSetting> is the same as not specifying the argument at all — both return the current setting.
DBOI_EXPRESSIONReturns the order key expression of the specified order as a string.
DBOI_FILEHANDLEReturns the handle of the specified index file as a number.
DBOI_FULLPATHReturns the full path of the specified index file as a string.
DBOI_HPLOCKINGReturns a logical flag indicating whether the specified index file uses the high performance index locking schema (see IndexHPLock() function).
DBOI_INDEXEXTReturns the default index file extension as a string.
DBOI_INDEXNAMEReturns the name of the specified index file as a string.
DBOI_ISCONDReturns a logical flag that determines whether the specified order was defined using a for condition.
DBOI_ISDESCReturns the logical flag that determines if the specified order is descending.  For drivers that support dynamically setting the descending flag at runtime, specify the new value as a logical, using DBServer:OrderInfo(DBOI_ISDESC, [<oFSIndexFile> | <cIndexFile>], [<cOrder> | <nPosition>], <lNewSetting>).  The current setting is returned before it is changed.
DBOI_KEYCOUNTReturns the number of keys in the specified order.
DBOI_KEYDECReturns the number of decimals in the key of the specified order.
DBOI_KEYSINCLUDEDReturns the number of keys included in the specified order so far.  This is primarily useful for conditional orders.  It can be used during the status display process (with the EVAL clause of the INDEX command).
DBOI_KEYSIZEReturns the size of the key in the specified order as a number.
DBOI_KEYTYPEReturns the data type of the key in the specified order as a string.
DBOI_KEYVALReturns the key value of the current record in the specified order.
DBOI_LOCKOFFSETReturns the locking offset (see NewIndexLock() function) for the specified index file as a numeric value.
DBOI_NAMEReturns the name of the specified order as a string.
DBOI_NUMBERReturns the numeric position of the specified order in the order list.
DBOI_ORDERCOUNTReturns the number of orders defined in the specified index file.
DBOI_POSITIONReturns the logical record number of the current record within the specified order.
DBOI_RECNOReturns the physical record number of the current record within the specified order.
DBOI_SCOPEBOTTOMsReturns the bottom boundary of the scope for the specified order.
DBOI_SCOPETOPReturns the top boundary of the scope for the specified order.
DBOI_SETCODEBLOCKReturns the key for the specified order as a code block.
DBOI_UNIQUEReturns a logical flag indicating whether the specified order has the unique attribute set.
Examples
This example uses DBOI_NAME to save the current controlling order.  After changing to a new controlling order, it uses the saved value to restore the original order:
X#
1oDBCust := Customer{}
2oDBCust:SetIndex("name")
3oDBCust:SetIndex("serial")
4cOrder := oDBCust:OrderInfo(DBOI_NAME)        // name
5oDBCust:SetOrder("serial")
6? oDBCust:OrderInfo(DBOI_NAME)            // serial
7oDBCust:SetOrder(cOrder)
8? oDBCust:OrderInfo(DBOI_NAME)            // name
This example returns the default index file extension (using DBOI_INDEXEXT) for two different data servers:
X#
1oDBSales := Sales{}
2oDBCust := Customer{}
3? oDBSales:OrderInfo(DBOI_INDEXEXT)            // .CDX
4? oDBCust:OrderInfo(DBOI_INDEXEXT)             // .NTX
In this example, DBServer:OrderInfo(DBOI_INDEXEXT) checks for the existence of the CUSTOMER index file independent of the RDD associated with the data server:
X#
1oDBCust := Customer{}
2IF !File("customer" + oDBCust:OrderInfo(DBOI_INDEXEXT))
3oDBCust:CreateIndex("customer", "oDBCust:CustName")
4ENDIF
This example accesses the key expression of several orders from the same index file:
X#
1oDBCust := Customer{}
2oDBCust:SetOrder("serial")
3? oDBCust:OrderInfo(DBOI_EXPRESSION,, "name")
4// Result: key expression for name order
5? oDBCust:OrderInfo(DBOI_EXPRESSION,, "serial")
6// Result: key expression for serial order
In this example, ALL_CUST.MDX contains three orders named CUACCT, CUNAME, CUZIP.  The DBOI_INDEXNAME constant is used to display the name of the index file using one of its orders:
X#
1oDBCust := Customer{}
2oDBCust:SetIndex("all_cust")
3? oDBCust:OrderInfo(DBOI_INDEXNAME,, "cuname")
4// Returns: all_cust
The following example searches for CUNAME in the order list:
X#
1oDBCust := Customer{}
2oDBCust:SetIndex("cuacct")
3oDBCust:SetIndex("cuname")
4oDBCust:SetIndex("cuzip")
5? oDBCust:OrderInfo(DBOI_NUMBER,, "cuname")  // 2
This example retrieves the "for condition" from an order:
X#
1oDBCust := Customer{}
2oDBCust:SetOrderCondition("oDBCust:Acct > 'AZZZZZ'")
3oDBCust:CreateIndex("customer", "oDBCust:Acct")
4oDBCust:OrderInfo(DBOI_CONDITION,, "customer")
5// Returns: oDBCust:Acct > 'AZZZZZ'
See Also