// BDE - (C) Copyright 1995 by Borland International

// LnkCrsr.c
#include "snipit.h"

static const char szMasterTable[] = "customer";
static const char szDetailTable[] = "orders";
static const char szTblType[] = szPARADOX;

//=====================================================================
//  Function:
//          LnkCrsr();
//
//  Description:
//          Linking cursors establishes a link between two cursors
//          such that the detail cursor has its record set limited to
//          the set of records matching the linking key values of the
//          master cursor.
//=====================================================================
void
LnkCrsr (void)
{
    hDBIDb      hDb;                // Handle to the database
    hDBICur     hCurMaster;         // Handle to the master table
    hDBICur     hCurDetail;         // Handle to the detail table
    UINT32      ulNumRecs = 10;     // Number of records to display,
                                    //   0 = all
    UINT16 uFieldsMaster[] = {1};   // Link the first field of Customer
    UINT16 uFieldsDetail[] = {2};   // To the second field of Orders
                                    //   (which is indexed)
    DBIResult   rslt;               // Return value from IDAPI functions

    Screen("*** Linked Cursors Example ***\r\n");

    BREAK_IN_DEBUGGER();

    Screen("    Initializing the engine...");
    if (InitAndConnect(&hDb) != DBIERR_NONE)
    {
        Screen("\r\n*** End of Example ***");
        return;
    }

    Screen("    Setting the database directory...");
    rslt = DbiSetDirectory(hDb, (pCHAR) szTblDirectory);
    ChkRslt(rslt, "SetDirectory");

    Screen("    Open the %s master table...", szMasterTable);
    rslt = DbiOpenTable(hDb, (pCHAR) szMasterTable, (pCHAR) szTblType,
                        NULL, NULL, 0, dbiREADWRITE, dbiOPENSHARED,
                        xltFIELD, FALSE, NULL, &hCurMaster);
    if (ChkRslt(rslt, "OpenTable") != DBIERR_NONE)
    {
        CloseDbAndExit(&hDb);
        Screen("\r\n*** End of Example ***");
        return;
    }

    Screen("    Display the first %lu records of the %s master table...",
           ulNumRecs, szMasterTable);
    DisplayTable(hCurMaster, ulNumRecs);

    Screen("\r\n    Open the %s detail table...", szDetailTable);
    rslt = DbiOpenTable(hDb, (pCHAR) szDetailTable, (pCHAR) szTblType,
                        NULL, NULL, 0, dbiREADWRITE, dbiOPENSHARED,
                        xltFIELD, FALSE, NULL, &hCurDetail);
    if (ChkRslt(rslt, "OpenTable") != DBIERR_NONE)
    {
          CloseDbAndExit(&hDb);
          Screen("\r\n*** End of Example ***");
          return;
     }

    Screen("    Display the first %lu records of the %s detail table...",
           ulNumRecs, szDetailTable);
    DisplayTable(hCurDetail, ulNumRecs);

    Screen("\r\n    Set to the Customer_No index on the detail table...");
    rslt = DbiSwitchToIndex(&hCurDetail, NULL, NULL, 2, FALSE);
    ChkRslt(rslt, "SwitchToIndex");

    Screen("    Link the tables...");

    // Put the Customer table into link mode.
    rslt = DbiBeginLinkMode(&hCurMaster);
    ChkRslt(rslt, "BeginLinkMode");

    // Put the Orders table into link mode.
    rslt = DbiBeginLinkMode(&hCurDetail);
    ChkRslt(rslt, "BeginLinkMode");

    // Link the two tables, specifying which fields
    //   will be linked in the last two parameters.
    //   Specifically, link the first field of Customers
    //   to the indexed second field of Orders.
    rslt = DbiLinkDetail(hCurMaster, hCurDetail, 1, uFieldsMaster,
                         uFieldsDetail);
    ChkRslt(rslt, "LinkDetail");

    Screen("    Display the %s detail table after the link:",
           szDetailTable);
    Screen("        Note that all Customer numbers correspond to the last"
           " record displayed in\r\n            the master table");
    DisplayTable(hCurDetail, ulNumRecs);

    Screen("\r\n    End the link...");

    // Unlink the detail table from the master table.
    rslt = DbiUnlinkDetail(hCurDetail);
    ChkRslt(rslt, "EndLinkMode");

    // Take the Customer table out of link mode.
    rslt = DbiEndLinkMode(&hCurMaster);
    ChkRslt(rslt, "EndLinkMode");

    // Take the Orders table out of link mode.
    rslt = DbiEndLinkMode(&hCurDetail);
    ChkRslt(rslt, "EndLinkMode");

    Screen("    Close the tables...");

    // Close the master table.
    rslt = DbiCloseCursor(&hCurMaster);
    ChkRslt(rslt, "CloseCursor");

    // Close the detail table.
    rslt = DbiCloseCursor(&hCurDetail);
    ChkRslt(rslt, "CloseCursor");

    Screen("    Close the database and exit IDAPI...");
    CloseDbAndExit(&hDb);

    Screen("\r\n*** End of Example ***");
}