Update doc

Author: alinaliBQ

cpp/src/arrow/flight/sql/odbc/odbc_impl/odbc_statement.cc

@@ -737,11 +737,12 @@ bool ODBCStatement::GetData(SQLSMALLINT record_number, SQLSMALLINT c_type,
 
 void ODBCStatement::GetRowCount(SQLLEN* row_count_ptr) {
   if (!row_count_ptr) {
-    // row_count_ptr is not valid, do nothing as ODBC spec does not mention this as an
+    // row count pointer is not valid, do nothing as ODBC spec does not mention this as an
     // error
     return;
   }
-  // Will always be -1 (number of rows unknown) if only SELECT is supported
+  // Will always be -1 (meaning number of rows unknown) since only SELECT is supported by
+  // driver
   *row_count_ptr = -1;
 }
 

cpp/src/arrow/flight/sql/odbc/odbc_impl/odbc_statement.h

@@ -80,9 +80,9 @@ class ODBCStatement : public ODBCHandle<ODBCStatement> {
   bool GetData(SQLSMALLINT record_number, SQLSMALLINT c_type, SQLPOINTER data_ptr,
                SQLLEN buffer_length, SQLLEN* indicator_ptr);
 
-  /**
-   * @brief Get number of rows affected by an UPDATE, INSERT, or DELETE statement
-   */
+  /// \brief Return number of rows affected by an UPDATE, INSERT, or DELETE statement\
+  ///
+  ///  -1 is returned as driver only supports SELECT statement
   void GetRowCount(SQLLEN* row_count_ptr);
 
   /**