connecting to a database server

... reason, ADO.NET automatically stores database connections in a pool. Connection pooling offers a great performance improvement because you don't have to wait for a brand new connection to the ... database to be established when there's a suitable connection already available. When you close a connection, that connection isn't actually closed; instead, your connection is marked ... " ;server= localhost ;database= Northwind;uid=sa;pwd=sa"; where server specifies the name of the computer on which SQL Server is running. database specifies the name of the database. uid...

Ngày tải lên: 07/11/2013, 10:15

... class. The following example defines a method named StateChangeHandler to handle the StateChange event. You'll notice that the second parameter to this method is a StateChangeEventArgs ... request to the database; two examples of states are open and closed. You use the Connection object's State property to get the current state of the connection to the database. The State property ... SqlConnection(" ;server= localhost ;database= Northwind;uid=sa;pwd=sa"); // monitor the StateChange event using the StateChangeHandler() method mySqlConnection.StateChange += new StateChangeEventHandler(StateChangeHandler);...

Ngày tải lên: 14/12/2013, 13:15

... Manager and Query Analyzer are also shared. The System.Data.SqlClient class cannot automatically discover the port number of a named instance of SQL Server listening on a port other than ... need to understand what a SQL Server or MSDE named instance is and how to connect to one. The sample code contains a single event handler: Connect Button.Click Creates and opens a connection to ... [ Team LiB ] Recipe 1.7 Connecting to a Named Instance of SQL Server or Microsoft Data Engine (MSDE) Problem You want to connect to a named instance of a SQL Server or Microsoft Data Engine...

Ngày tải lên: 14/12/2013, 18:16

... several provider-specific connection string attributes in addition to those defined by ADO.NET. To open a database secured by a Microsoft Access database password, use the Jet OLEDB :Database Password ... the password has unrestricted access to the database. The Set Database command from the Tools Security menu is used to set up a database password. The OLE DB provider for Microsoft Jet has several ... obtain access to the database and database objects. This is also known as share-level security. A password does not allow groups or users to have distinct levels of access or permissions. Anyone...

Ngày tải lên: 24/12/2013, 05:15

... Team LiB ] [ Team LiB ] Recipe 1.4 Connecting to a Secured Access Database Problem You want to connect to a Microsoft Access database that has been secured with user-level security and ... database. The sample code contains a single event handler: Connect Button.Click Creates and opens a connection to a Microsoft Access database secured with user- level security and a workgroup ... defined by ADO.NET. To open a database secured by Microsoft Access user-level security, use the Jet OLEDB:System Database attribute in the connection string to specify the path and filename of...

Ngày tải lên: 24/12/2013, 05:15

Ngày tải lên: 21/01/2014, 11:20

... Create a SQL SELECT statement referencing a worksheet or a range in an Excel workbook and execute the statement to fill a DataSet using a DataAdapter or to create a DataReader. For example: ... INSERT INTO [MySheet$] (Field1, Field2, Field3) VALUES ('testdata', 1.234, '09/28/1979'); Retrieve data Use either a DataAdapter or a DataReader to retrieve data from an Excel ... 1-2 . Example 1-2. File: ExcelForm.cs // Namespaces, Variables, and Constants using System; using System.Configuration; using System.Data; private OleDbDataAdapter da; private DataTable...

Ngày tải lên: 14/12/2013, 18:16

... provider can read records from and insert records into a text file data source. The Jet database engine can access other database file formats through Indexed Sequential Access Method (ISAM) drivers ... data adapter to retrieve all rows from text file. The MaxScanRows option indicates how many rows should be scanned to automatically determine column type. A value of 0 indicates that all rows ... provider to access data in a text file. The sample code creates an OleDbDataAdapter that uses the Jet OLE DB provider to load the contents of the text file Categories.txt, shown in Example 1-13 ,...

Ngày tải lên: 24/12/2013, 05:15

... demonstrates how to store XML data in a text field of a database table and subsequently read it into an XmlDocument using the LoadXml( ) method. Standard database access techniques using a DataAdapter ... sender, System.EventArgs e) { DataSet ds = new DataSet( ); // Fill the Categories table and add it to the DataSet. SqlDataAdapter da = new SqlDataAdapter("SELECT TOP 3 * FROM Orders", ... da.SelectCommand.Connection); da.UpdateCommand.CommandType = CommandType.Text; da.UpdateCommand.Parameters.Add("@Id", SqlDbType.Int, 0, "Id"); da.UpdateCommand.Parameters.Add("@XmlField",...

Ngày tải lên: 24/12/2013, 05:15

Ngày tải lên: 21/01/2014, 11:20

Ngày tải lên: 23/10/2014, 18:38

Ngày tải lên: 24/10/2014, 10:51

Ngày tải lên: 21/01/2014, 12:20

Ngày tải lên: 31/03/2014, 16:20

... Kế Một Database Tạo Một User Database Chúng ta có thể tạo một database dễ dàng dùng SQL Server Enterprise bằng cách right-click lên trên " ;database& quot; và chọn "New Database& quot; ... SQL Server hay khi ta disconnect. ã Model : Database này đóng vai trò như một bảng kẻm (template) cho các database khác. Ngh a là khi một user database được tạo ra thì SQL Server sẽ copy to n ... 2000, thông thường đó là Default Instance. Một Instance c a SQL Server 2000 có 4 system databases và mt hay nhiu user database. Cỏc system databases bao gm: ã Master : Ch a tất cả những thông tin...

Ngày tải lên: 25/08/2012, 09:00

... user database được tạo ra thì SQL Server sẽ copy to n bộ các system objects (tables, stored procedures ) từ Model database sang database mi va to. ã Msdb : Database này được SQL Server Agent ... Sp_help ['object'] Cung cấp thông tin về một database object (table, view ) hay một data type. Sp_helpdb [&apos ;database& apos;] Cung cấp thông tin về một database cụ thể nào đó. Sau đó ... (schedule alerts and jobs). 3.2. Cấu Trúc Vật Lý C a Một SQL Server Database Mỗi một database trong SQL Server đều ch a ít nhất một data file chính (primary), có thể có thêm một hay nhiều data file...

Ngày tải lên: 06/10/2013, 17:20

... from changing data being read by a user and preventing users from reading data being changed by a user. Locks are acquired and released by user actions; they are managed internally by database ... Fill table using the DataAdapter. DataTable dt = new DataTable( ); da.Fill(dt); // Bind the default view of the table to the grid. dataGrid.DataSource = dt.DefaultView; cancelButton.Enabled ... ReadCommitted. A DataAdapter is used on the transacted connection to fill a DataTable. A CommandBuilder is created to generate updating logic. The default view of the table is bound to the data grid on...

Ngày tải lên: 17/10/2013, 20:15

... SQL Server and a DataSet object. You'll learn the details on how to pull rows from the database into a DataSet in Chapter 10 , and how to push changes made in a DataSet to the database ... need to create a DataSet object. You use a DataSet object to a store local copy of the information stored in the database. A DataSet object can represent database structures such as tables, ... property, as shown in Figure 6.11 . Using a DataGrid Control to Access a Database In this section, you'll learn how to use a DataGrid control to access the rows in a database table. Follow...

Ngày tải lên: 07/11/2013, 10:15

... as a transaction with an isolation level of READ COMMITTED. READUNCOMMITTED Same as NOLOCK. REPEATABLEREAD Use the same locking as a transaction with an isolation level of REPEATABLE READ. ... SqlCommand cmd = new SqlCommand(sqlText, conn, tran); // Create the DataAdapter and CommandBuilder. SqlDataAdapter da = new SqlDataAdapter(cmd); SqlCommandBuilder cb = new SqlCommandBuilder(da); ... Fill table using the DataAdapter. DataTable dt = new DataTable( ); da.Fill(dt); // Bind the default view of the table to the grid. dataGrid.DataSource = dt.DefaultView; cancelButton.Enabled...

Ngày tải lên: 14/12/2013, 18:16

... configuration file named TNSNAMES.ORA to locate the Oracle database and determine how to connect to it based on the Data Source or Database attribute in the connection string. An example of an entry ... Oracle Button.Click Creates and opens a connection to an Oracle database using the Oracle .NET data provider. Information about the database is displayed from the properties of the OracleConnection ... to an Oracle database. Solution You can connect to an Oracle database using either the Oracle .NET data provider or the OLE DB .NET data provider. The sample code contains two event handlers:...

Ngày tải lên: 24/12/2013, 05:15