OP Subselection to array

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version 1.5


OP Subselection to array (connectionID; bindID; firstRecord; lastRecord{; tableID}) Longint

ParameterTypeDescription
connectionIDLongintConnection ID with target server
bindIDLongintBind list ID
firstRecordLongintRelative number of first record
to retrieve in current selection
lastRecordLongintRelative number of last record
to retrieve in current selection
tableIDLongintNumber of the table in the database
Function resultLongintError code result for the function

Description

OP Subselection to array works exactly like OP Selection to array, except that instead of loading values from all records in the selection, it loads values from records relatively placed in the current selection, between firstRecord and lastRecord.

For a complete discussion of this commands functionalities refer to OP Selection to array.

Example

This example exports customer names to a text file. In order to avoid creating large array from a large [Customers] table, it loads the values in 'chunks' of 100 at a time.

   C_LONGINT ($errCode;vRecords;$custNamesBind)
   ARRAY STRING (40;aCustName;0)

   ` Create a new bind list
   $ErrCode := OP Create bind ($custNamesBind)
   ` Add to the list a bind between [Customers]Company (1;2) and the aCustName array
   $ErrCode := $ErrCode + OP Define bind by pointer ($custNamesBind;1;2;->aCustName)

   ` Select all records in the [Customers] table (table 1)
   $ErrCode:= OP All records (vConnectID;1)

   ` Get the number of records selected
   $errCode := OP Records in selection (vConnectID;1;vRecords)

   $i:=0
   While ($i<vRecords)
      ` Load 100 customers names into the array
      $errCode := OP Subselection to array ( vConnectID; $custNamesBind ; $i+1; $i+100)
      ExportCustNames (->aCustName)
      $i := $i + 100
   End while
   
   $errCode := OP Delete bind ($custNamesBind)

See Also

OP Define bind by pointer, OP Get one field number, OP Records in selection, OP Selection to array, OP Subselection to array.


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