Contoh Kode Pustaka Kursor

Penting

Fitur ini akan dihapus dalam versi Windows yang akan datang. Hindari menggunakan fitur ini dalam pekerjaan pengembangan baru dan rencanakan untuk memodifikasi aplikasi yang saat ini menggunakan fitur ini. Microsoft merekomendasikan penggunaan fungsionalitas kursor driver.

Contoh berikut menggunakan pustaka kursor untuk mengambil ID, tanggal buka, dan status setiap pesanan dari tabel ORDERS. Kemudian menampilkan 20 baris data. Jika pengguna memperbarui data ini, kode memperbarui buffer set baris dan menjalankan pernyataan pembaruan yang diposisikan. Terakhir, ini meminta pengguna untuk arah untuk menggulir dan mengulangi proses.

#define ROWS 20  
#define STATUS_LEN 6  
#define OPENDATE_LEN 11  
#define DONE -1  
  
SQLHENV        henv;  
SQLHDBC        hdbc;  
SQLHSTMT       hstmt1, hstmt2;  
SQLRETURN      retcode;  
SQLCHAR        szStatus[ROWS][STATUS_LEN],   
               szOpenDate[ROWS][OPENDATE_LEN];  
SQLCHAR        szNewStatus[STATUS_LEN], szNewOpenDate[OPENDATE_LEN];  
SQLSMALLINT    sOrderID[ROWS], sNewOrderID[ROWS];  
SQLINTEGER     cbStatus[ROWS], cbOrderID[ROWS], cbOpenDate[ROWS];  
SQLUINTEGER    FetchOrientation, crow, FetchOffset, irowUpdt;  
SQLUSMALLINT   RowStatusArray[ROWS];  
  
SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &henv);  
SQLSetEnvAttr(henv, SQL_ATTR_ODBC_VERSION, SQL_OV_ODBC3,0);  
SQLAllocHandle(SQL_HANDLE_DBC, henv, &hdbc);  
  
// Specify that the ODBC Cursor Library is always used, then connect.  
  
SQLSetConnectAttr(hdbc, SQL_ATTR_ODBC_CURSORS, SQL_CUR_USE_ODBC);  
SQLConnect(hdbc, "SalesOrder", SQL_NTS,  
            "JohnS", SQL_NTS,  
            "Sesame", SQL_NTS);  
  
if (retcode == SQL_SUCCESS || retcode == SQL_SUCCESS_WITH_INFO) {  
  
   /* Allocate a statement handle for the result set and a statement */  
   /* handle for positioned update statements. */  
  
   SQLAllocHandle(SQL_HANDLE_STMT, hdbc, &hstmt1);  
   SQLAllocHandle(SQL_HANDLE_STMT, hdbc, &hstmt2);  
  
   /* Specify an updatable static cursor with 20 rows of data. Set */  
   /* the cursor name, execute the SELECT statement, and bind the */  
   /* rowset buffers to result set columns in column-wise fashion. */  
   SQLSetStmtAttr(hstmt1, SQL_ATTR_CONCURRENCY, SQL_CONCUR_VALUES, 0);  
   SQLSetStmtAttr(hstmt1, SQL_ATTR_CURSOR_TYPE, SQL_CURSOR_STATIC, 0);  
   SQLSetStmtAttr(hstmt1, SQL_ATTR_ROW_ARRAY_SIZE, ROWS, 0);  
   SQLSetStmtAttr(hstmt1, SQL_ATTR_ROW_STATUS_PTR, RowStatusArray, 0);  
   SQLSetStmtAttr(hstmt1, SQL_ATTR_ROWS_FETCHED_PTR, &crow, 0);  
   SQLSetCursorName(hstmt1, "ORDERCURSOR", SQL_NTS);  
   SQLExecDirect(hstmt1,  
                  "SELECT ORDERID, OPENDATE, STATUS FROM ORDERS ",  
                  SQL_NTS);  
   SQLBindCol(hstmt1, 1, SQL_C_SSHORT, sOrderID, 0, cbName);  
   SQLBindCol(hstmt1, 2, SQL_C_CHAR, szOpenDate, OPENDATE_LEN, cbOpenDate);  
   SQLBindCol(hstmt1, 3, SQL_C_CHAR, szStatus, STATUS_LEN, cbStatus);  
  
   /* Fetch the first block of data and display it. Prompt the user */  
   /* for new data values. If the user supplies new values, update */  
   /* the rowset buffers, bind them to the parameters in the update */  
   /* statement, and execute a positioned update on another hstmt. */  
   /* Prompt the user for how to scroll. Fetch and redisplay data as */  
   /* needed. */  
  
   FetchOrientation = SQL_FETCH_FIRST;  
   FetchOffset = 0;  
   do {  
  
      SQLFetchScroll(hstmt1, FetchOrientation, FetchOffset);  
      DisplayRows(sOrderID, szOpenDate, szStatus, RowStatusArray);  
  
      if (PromptUpdate(&irowUpdt,&sNewOrderID,szNewOpenDate,szNewStatus)==TRUE){  
         sOrderID[irowUpdt] = sNewOrderID;  
         cbOrderID[irowUpdt] = 0;  
         strcpy_s((char*)szOpenDate[irowUpdt], _countof(szOpenDate[irowUpdt]), szNewOpenData);  
         cbOpenDate[irowUpdt] = SQL_NTS;  
         strcpy_s((char*)szStatus[irowUpdt], _countof(szStatus[irowUpdt]), szNewStatus);  
         cbStatus[irowUpdt] = SQL_NTS;  
         SQLBindParameter(hstmt2, 1, SQL_PARAM_INPUT,  
                           SQL_C_SSHORT, SQL_INTEGER, 0, 0,  
                           &sOrderID[irowUpdt], 0, &cbOrderID[irowUpdt]);  
         SQLBindParameter(hstmt2, 2, SQL_PARAM_INPUT,  
                           SQL_C_CHAR, SQL_TYPE_DATE, OPENDATE_LEN, 0,  
                           szOpenDate[irowUpdt], OPENDATE_LEN, &cbOpenDate[irowUpdt]);  
         SQLBindParameter(hstmt2, 3, SQL_PARAM_INPUT,  
                           SQL_C_CHAR, SQL_CHAR, STATUS_LEN, 0,  
                           szStatus[irowUpdt], STATUS_LEN, &cbStatus[irowUpdt]);  
         SQLExecDirect(hstmt2,  
                        "UPDATE EMPLOYEE SET ORDERID = ?, OPENDATE = ?, STATUS = ?"  
                        "WHERE CURRENT OF EMPCURSOR",  
                        SQL_NTS);  
      }  
  
   while (PromptScroll(&FetchOrientation, &FetchOffset) != DONE)  
}