ado.net

问题 I'm in the middle of a project where we are querying a database with more than 20 million records, applying several set of filters our query returns about 200 records (after waiting for about 1.30 minutes). After querying the database I try to create objects from this particular datareader but once every 15 or 16 records the asp.net process hangs (it hangs in the debugger) so I think it is a DataReader issue. This is driving me crazy. Here's the code I'm using using (IDataReader reader = cmd

问题 I want to know what is the difference between creating a database in app_data and connecting to a external database. i went through this question.but i am not clear idea. What's the difference between the database inside App_Data folder vs connecting to SQL Server? what is the advantages/disadvantage of using each type. 回答1: while developing, you will not see a big difference between both of them, but as many know, SQL server express has some limitations ( like supporting only 1 CPU) and this

问题 I am starting with the Entity Framework. It sounds great. But I am wondering if I should watch out for some weakness somewhere. Any experience there? 回答1: You probably need to start prefixing these questions with the version you are talking about. A good amount of the annoyances have been fixed in the upcoming version in .NET 4.0. Here is what I would say after working with the first version for about 6 months using a decent size DB in sql 2k8(40+ tables, several tables with close to 1M rows,

问题 I have two DateTime objects, BirthDate and HireDate. They are correctly formatted as a string and when I pass them through to my data access layer, they need to be parsed into a DateTime object. DateTime hD = DateTime.Parse(hire); DateTime bD = DateTime.Parse(birth); //incase of a datestring being passed through dateStringPassed = "7/2/1969"; But sometimes, the strings hire and birth are null or empty "" , if the code is run like this, I get a FormatException error from Parsing a empty string

问题 We are having problems on one machine, with the error message: "MSDTC on server XXX is unavailable." The code is using a TransactionScope to wrap some LingToSql database code; there is also some raw Ado.net inside of the transaction. As only a single sql database (2005) is being accessed, why is a distributed transaction being used at all? (I don’t wish to know how to enable MSDTC, as the code needs to work on the server with their current setup) 回答1: This almost always happens when your

问题 We are having problems on one machine, with the error message: "MSDTC on server XXX is unavailable." The code is using a TransactionScope to wrap some LingToSql database code; there is also some raw Ado.net inside of the transaction. As only a single sql database (2005) is being accessed, why is a distributed transaction being used at all? (I don’t wish to know how to enable MSDTC, as the code needs to work on the server with their current setup) 回答1: This almost always happens when your

问题 The dt.Select(string) gives error missing operand when apostrophe symbol is in the string. what is the way to solve this error? or How to handle this error? 回答1: String value = "Rubens' Home"; // value you want to sanitize and search dt.Select(String.Format( "Location = '{0}'", value.Replace("'", "''"))); 来源： https://stackoverflow.com/questions/4906384/how-do-i-include-an-apostrophe-in-the-string-passed-to-datatable-select

问题 I have a method that allows me to kick off a back up of a data base. What I am wondering is if I should be using ExecuteNonQuery() in this context or if there is something better to use. Here is my code currently: public static void RunBackup(string dbName, string filePath, string backupName, string connString) { using(SqlConnection objConnection = new SqlConnection(connString)) { string commmandText = "BACKUP DATABASE @DBName TO DISK = @FilePath WITH NOFORMAT, NOINIT, NAME = @BackUpName,

问题 I have a method that allows me to kick off a back up of a data base. What I am wondering is if I should be using ExecuteNonQuery() in this context or if there is something better to use. Here is my code currently: public static void RunBackup(string dbName, string filePath, string backupName, string connString) { using(SqlConnection objConnection = new SqlConnection(connString)) { string commmandText = "BACKUP DATABASE @DBName TO DISK = @FilePath WITH NOFORMAT, NOINIT, NAME = @BackUpName,

问题 I have the code below, I have read Moq and SqlConnection? and How can I stub IDBconnection, but I still have no idea how to mock the following sqlconnection. public class SqlBulkWriter : ISqlBulkWriter { private readonly string _dbConnectionString;; public SqlBulkWriter(string dbConnectionString) { this._dbConnectionString = dbConnectionString; } public void EmptyTable(string schema, string tableName) { using (var connection = new SqlConnection(this._dbConnectionString)) { try { connection