What are the common C # codes in database?

This article mainly introduces what the database commonly used C # code has, which has a certain reference value, interested friends can refer to, I hope you can learn a lot after reading this article, let the editor take you to understand it.

Create a database

/ / create the database File.Delete ("Test.sdf"); SqlCeEngine engine = new SqlCeEngine ("Data Source='Test.sdf';LCID=1033;Password=\" slottery 2); Encrypt=TRUE; "); engine.CreateDatabase ()

Verify and repair the database

/ / verify and repair the database SqlCeEngine engine = new SqlCeEngine ("Data Source=AdventureWorks.sdf"); if (false = = engine.Verify ()) {MessageBox.Show ("Database is corrupted."); engine.Repair (null, RepairOption.RecoverCorruptedRows);}

Compress database

/ / compress the database / / reclaim the wasted space in the SQL Server Mobile database by creating a new database file from the existing file. / / this method can also be used to change the sort order, encryption, or password settings of the database. / / the connection string specifies a connection to the target database to be created by this method. An exception is thrown if the specified database already exists or another file with the same name already exists. / / if you pass an empty string for the connection string, the new database file will overwrite the old database file, / / but the name remains the same. SqlCeEngine engine = new SqlCeEngine ("Data Source=AdventureWorks.sdf"); / / engine.Compact (null); engine.Compact ("Data Source=; passwordholders)

Shrink the database

/ / shrink the database / / reclaim wasted space in the SQL Server Mobile database by moving empty pages to the end of the file and truncating the file. / / unlike the Compact method, the Shrink method does not create a tempdb file, / / but moves all empty and unallocated pages to the end of the file and then truncates, thereby reducing the total size of the database. SqlCeEngine engine = new SqlCeEngine ("Data Source=AdventureWorks.sdf"); engine.Shrink ()

Merge replication

/ / merge replication / / instantiate and configure SqlCeReplication objects SqlCeReplication repl = new SqlCeReplication (); repl.InternetUrl = "http://www.adventure-works.com/sqlmobile/sqlcesa30.dll"; repl.InternetLogin =" MyInternetLogin "; repl.InternetPassword ="; repl.Publisher =" MyPublisher "; repl.PublisherDatabase =" MyPublisherDatabase "; repl.PublisherLogin =" MyPublisherLogin "; repl.PublisherPassword ="; repl.Publication =" MyPublication "; repl.Subscriber =" MySubscriber " Repl.SubscriberConnectionString = "Data Source=MyDatabase.sdf"; / / create a subscription repl.AddSubscription (AddOption.CreateDatabase) of a local SQL Server Mobile database; / / synchronize repl.Synchronize () with the SQL Server database; / / clean up the repl object repl.Dispose ()

Remote data access (RDA)

/ / remote data access / / instantiate and configure SqlCeRemoteDataAccess objects SqlCeRemoteDataAccess rda = new SqlCeRemoteDataAccess (); rda.InternetUrl = "http://www.adventure-works.com/sqlmobile/sqlcesa30.dll"; rda.InternetLogin =" MyInternetLogin "; rda.InternetPassword ="; rda.LocalConnectionString =" Data Source=MyDatabase.sdf "; / / download data rda.Pull (" Employees "," SELECT * FROM DimEmployee "," Provider=sqloledb;server=MySqlServer;database=AdventureWorks;uid=sa;pwd= ") from SQL Server ", RdaTrackOption.TrackingOnWithIndexes," ErrorTable "); / / modify local data / upload modified data to SQL Server rda.Push (" DimEmployee "," Provider=sqloledb;server=MySqlServer;database=AdventureWorks;uid=sa;pwd=; "); / / submit SQL statements to execute rda.SubmitSql (" CREATE TABLE MyRemoteTable (colA int) "," Provider=sqloledb;server=MySqlServer;database=AdventureWorks;uid=sa;pwd=; ") on SQL Server

Use SqlCeResultSet

/ / use SqlCeResultSet / / to create a SQL Server Mobile database connection SqlCeConnection conn = new SqlCeConnection ("Data Source=Northwind.sdf"); / / create and configure SqlCeCommand objects SqlCeCommand cmd = conn.CreateCommand (); cmd.CommandText = "SELECT * FROM Orders"; / / create SqlCeResultSet objects and configure them to be scrollable, updatable, and detect data source changes ResultSetOptions options = ResultSetOptions.Scrollable | ResultSetOptions.Sensitive | ResultSetOptions.Updatable; SqlCeResultSet resultSet = cmd.ExecuteResultSet (options) / / create a ResultSetView object that is configured to display only the column ResultSetView resultSetresultSetView = resultSet.ResultSetView; int [] ordinals = new int [] {1mine3pm 5re8}; resultSetView.Ordinals = ordinals; / / bind ResultSetView to the DataGrid control this.dataGrid.DataSource = resultSetView

Dealing with SqlCeException

/ / handle SqlCeException public static void ShowErrors (SqlCeException e) {SqlCeErrorCollection eerrorCollection = e.Errors; StringBuilder bld = new StringBuilder (); Exception inner = e.InnerException; foreach (SqlCeError err in errs) {/ / HRESULT values that identify the type of errors that are not inherent in SQL Server CE ("\ r\ nError Code:") .append (err.HResult.ToString ("X")) / / A text bld.Append ("\ r\ nMessage:") .append (err.Message) that describes the error; / / gets the native error number of SqlCeError bld.Append ("\ r\ nMinor Err.:") .append (err.NativeError); / / the name of the provider that generated the error bld.Append ("\ r\ nSource:") .append (err.Source); / / traverses the first three error parameters. SQL Server CE uses error parameters to provide additional details about the error. Foreach (int numPara in err.NumericErrorParameters) {/ / although errors may have parameters, not all errors that occur return parameters. / / if no parameters are returned when an error occurs, the value of the array is 0. If (numPara! = 0) {bld.Append ("\ r\ nNum. Par.:") .append (numPara);}} / / traversal * * three error parameters. SQL Server CE uses error parameters to provide additional details about the error. Foreach (string errPara in err.ErrorParameters) {/ / although errors may have parameters, not all errors that occur return parameters. / / if no parameters are returned when an error occurs, the value of the array will be an empty string. If (errPara! = String.Empty) {bld.Append ("\ r\ nErr. Par.: ") .append (errPara);} MessageBox.Show (bld.ToString ());} Thank you for reading this article carefully. I hope the article" what are the common C # codes in the database "shared by the editor will be helpful to you? at the same time, I hope you will support us and pay attention to the industry information channel. More related knowledge is waiting for you to learn!