DbServer.OrderInfo Method

Return and optionally change information about orders and index files.

Namespace: VO
Assembly: VORDDClasses (in VORDDClasses.dll) Version: 2.21

Syntax

 VIRTUAL METHOD OrderInfo(
	kOrderInfoType,
	oFSIndex,
	uOrder,
	uOrdVal
) AS USUAL CLIPPER

[ClipperCallingConventionAttribute(new string[] { ... })]
public virtual Usual OrderInfo(
	Usual kOrderInfoType = default,
	Usual oFSIndex = default,
	Usual uOrder = default,
	Usual uOrdVal = default
)

Request Example View Source

Parameters

kOrderInfoType (Optional): Type: Usual
Specifies the type of information. The constants are listed below. Note, however, that not all constants are supported for all RDDs. This should be one of the DBOI_ constants listed in the remarks section.
oFSIndex (Optional): Type: Usual
A string or filespec object that specifies 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 (Optional): 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 (Optional): 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

Constant	Description
DBOI_CONDITION	Returns the for condition of the specified order as a string.
DBOI_CUSTOM	Returns 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_EXPRESSION	Returns the order key expression of the specified order as a string.
DBOI_FILEHANDLE	Returns the handle of the specified index file as an IntPtr.
DBOI_FILESTREAM	Returns the filestream of the specified index file.
DBOI_FULLPATH	Returns the full path of the specified index file as a string.
DBOI_HPLOCKING	Returns a logical flag indicating whether the specified index file uses the high performance index locking schema (see IndexHPLock() function).
DBOI_INDEXEXT	Returns the default index file extension as a string.
DBOI_INDEXNAME	Returns the name of the specified index file as a string.
DBOI_ISCOND	Returns a logical flag that determines whether the specified order was defined using a for condition.
DBOI_ISDESC	Returns 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_KEYCOUNT	Returns the number of keys in the specified order.
DBOI_KEYDEC	Returns the number of decimals in the key of the specified order.
DBOI_KEYSINCLUDED	Returns 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_KEYSIZE	Returns the size of the key in the specified order as a number.
DBOI_KEYTYPE	Returns the data type of the key in the specified order as a string.
DBOI_KEYVAL	Returns the key value of the current record in the specified order.
DBOI_LOCKOFFSET	Returns the locking offset (see NewIndexLock() function) for the specified index file as a numeric value.
DBOI_NAME	Returns the name of the specified order as a string.
DBOI_NUMBER	Returns the numeric position of the specified order in the order list.
DBOI_ORDERCOUNT	Returns the number of orders defined in the specified index file.
DBOI_POSITION	Returns the logical record number of the current record within the specified order.
DBOI_RECNO	Returns the physical record number of the current record within the specified order.
DBOI_SCOPEBOTTOMs	Returns the bottom boundary of the scope for the specified order.
DBOI_SCOPETOP	Returns the top boundary of the scope for the specified order.
DBOI_SETCODEBLOCK	Returns the key for the specified order as a code block.
DBOI_UNIQUE	Returns a logical flag indicating whether the specified order has the unique attribute set.
DBOI_USER	For customizations.

Tip
DBOI_USER is a constant that returns the minimum value that third-party RDD developers can use can use for customizations. Values less than DBOI_USER are reserved for X# development.

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:

Copy

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:

Copy

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:

Copy

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:

Copy

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:

Copy

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:

Copy

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:

Copy

1oDBCust := Customer{}
2oDBCust:SetOrderCondition("oDBCust:Acct > 'AZZZZZ'")
3oDBCust:CreateIndex("customer", "oDBCust:Acct")
4oDBCust:OrderInfo(DBOI_CONDITION,, "customer")
5// Returns: oDBCust:Acct > 'AZZZZZ'

Reference

DbServer Class

VO Namespace