ODBC Driver for Oracle OCI

Build 20.0.7654

Querying Data

After Connecting, you can allocate a statement handle and execute the statement.

SELECT Procedure

Use SQLExecDirect to execute the statement and SQLFetch to fetch the records. You can use SQLBindCol to bind variables to columns in the result set. The numbering of the result set columns starts at 1.

SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &henv); 
SQLSetEnvAttr(henv, SQL_ATTR_ODBC_VERSION, (void*)SQL_OV_ODBC3, 0); 
SQLAllocHandle(SQL_HANDLE_DBC, henv, &hdbc); 
SQLDriverConnect(hdbc, 0, (SQLCHAR*)"Dsn=CData OracleOci Source", SQL_NTS, 0, 0, 0, 0);
SQLAllocHandle(SQL_HANDLE_STMT, hdbc, &hstmt);
SQLExecDirect(hstmt, (SQLCHAR*)"SELECT City FROM Customers WHERE Country = 'US'", SQL_NTS);  
SQLCHAR sCity[20] = {0};
SQLLEN cbCity = 0;
SQLBindCol(hstmt, 1, SQL_C_CHAR, sCity, 20, &cbCity);
SQLRETURN retcode = SQLFetch(hstmt);
if (retcode == SQL_SUCCESS || retcode == SQL_SUCCESS_WITH_INFO) {
 ...
}

Iterating over the Results

You can use SQLGetData to get values while iterating through a cursor. To iterate over the results, use SQLFetch to fetch rows and SQLGetData to retrieve the column values.

  SQLHENV henv;
  SQLHDBC hdbc;
  SQLHSTMT hstmt;
  char sCompanyName[255] = {0};
  SQLLEN cbId = 0;
  if (SQLAllocHandle(SQL_HANDLE_ENV, 0 ,&henv) == SQL_SUCCESS) {
    SQLSetEnvAttr(henv, SQL_ATTR_ODBC_VERSION, (void*)SQL_OV_ODBC3, 0); 
    if (SQLAllocHandle(SQL_HANDLE_DBC, henv ,&hdbc) == SQL_SUCCESS) {
      if (SQLConnect(hdbc, "CData OracleOci Source", SQL_NTS, 0, 0, 0, 0) == SQL_SUCCESS) {
        if (SQLAllocHandle(SQL_HANDLE_STMT, hdbc ,&hstmt) == SQL_SUCCESS) {
          if (SQLExecDirect(hstmt, "SELECT CompanyName FROM Customers WHERE Country = 'US'", SQL_NTS) == SQL_SUCCESS) {
            while(SQLFetch(hstmt) == SQL_SUCCESS) {
              if (SQLGetData(hstmt, 1, SQL_C_CHAR, (SQLPOINTER)sCompanyName, 255, &cbId) == SQL_SUCCESS) {
                printf("CompanyName: %s\n", sCompanyName);
              }
            }
          }
          SQLFreeHandle(SQL_HANDLE_STMT, hstmt);
        }
        SQLDisconnect(hdbc);
      }
      SQLFreeHandle(SQL_HANDLE_DBC, hdbc);
    }
    SQLFreeHandle(SQL_HANDLE_ENV, henv);
  }

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Build 20.0.7654