CheckHeaderIsReady(columnIndex: i, methodName:"IsDBNullAsync"); }catch(Exception ex) {if(!ADP.IsCatchableExceptionType(ex)) {throw; }returnADP.CreatedTaskWithException<bool>(ex); } if((_sharedState._nextColumnHeaderToRead > i) && (!cancellationToken.IsCancellationRequested) && (_currentTask ...
c# Check registry if program is installed if yes get install location ? C# Check to make sure first character in a string is a letter C# check username if already exists from database C# Class - USB Port Enabled/Disabled Status Detection C# class for JSON is resulting a Null Reference Exc...
当用户尝试映射 DataReader 权限时,系统会经历几个状态: Check if user is mappedCheck permissionsAttempt to select DataReaderSuccessCannot access DataReaderEndUser_ExistsUser_MappedPermissions_AccessibleDataReader_AvailableDataReader_Unavailable 解决方案 针对以上问题,以下是一些具体的解决方案: 检查并授予必要权限 ...
要避免在任何情况下都要关闭SqlTransaction,if语句,trycatch语句,否则就会占用资源,阻止下一步数据库的访问: try { using (SqlConnection conn = new SqlConnection(GLibrary.ConnectionString)) { string sInsert = "", sUpdate = ""; int i = 0; SqlCommand cmd = null; SqlParameter pdon, pdoff; conn...
true if the specified column value is equivalent to DBNull; otherwise false. Remarks Call this method to check for null column values before calling the typed get methods (for example, GetByte, GetChar, and so on) to avoid raising an error. C# Copy using System; using System.Data; usin...
if (CheckTime()) { WriteErrorToFile.WriteException(WriteErrorToFile.FilePath(), "Service Started", "From function-Timer Proc"); NewThread = new Thread(() => Migratedata(APIkey, ApiBaseUrl, GroupName)); NewThread.Start(); } }
string photoName = await reader.IsDBNullAsync(0) ? string.Empty : await reader.GetFieldValueAsync<string>(0); // The photo data is also nullable, // so check if there is data available, otherwise we need to return null if (await reader.IsDBNullAsync(1)) { // No ...
如果源查询能够很容易地在SQL Server中进行批处理(例如，可以对其进行键控的聚集索引)，则FETCH和OFFSET...
How do I check if a DataReader has a column? How does ado net handle null value? Detect if DataReader is Void [Repeated] can be the Question: I'm constant receive the error: The method or property cannot be invoked on Null values as they contain no data. ...
SqlStatistics statistics = null; try { statistics = SqlStatistics.StartTimer(Statistics); if (null == _fieldNameLookup) { CheckMetaDataIsReady(); _fieldNameLookup = new FieldNameLookup(this, _defaultLCID); } return _fieldNameLookup.GetOrdinal(name); // MDAC 71470 ...