TAILIEUCHUNG - Developing Your First ADO.NET phần 2

Step 3: Set the CommandText Property of the SqlCommand Object You use SQL to work with the information stored in a database. SQL is an industry standard language supported by SQL Server, Access, and Oracle | Step 3 Set the CommandText Property of the SqlCommand Object You use SQL to work with the information stored in a database. SQL is an industry standard language supported by SQL Server Access and Oracle. You use the SQL SELECT statement for retrieving information from a database. You ll learn the basics of SQL in Chapter 3 Introduction to the Structured Query Language. Step 3 sets the CommandText property of mySqlCommand created in the previous step to a SELECT statement. This statement will retrieve the CustomerlD CompanyName ContactName and Address columns from the row in the Customers table whose CustomerlD is ALFKI SELECT CustomerlD CompanyName ContactName Address FROM Customers WHERE CustomerlD ALFKI Step 4 Open the SqlConnection Object Step 4 opens the database connection using the Open method of the SqlConnection object created in step 1 Once the connection to the database is open you can send commands to the database for execution. Step 5 Run the SELECT Statement You run the SELECT statement previously set in mySqlCommand by calling the ExecuteReader method. This method returns a SqlDataReader object that you then use to read the row data returned by the SELECT statement. Step 5 creates a SqlDataReader object and calls the ExecuteReader method of mySqlCommand object to run the SELECT statement SqlDataReader mySqlDataReader Step 6 Read the Row Using the SqlDataReader Object Step 6 reads the row in mySqlDataReader using the Read method Step 7 Display the Column Values from the SqlDataReader Object You can read the value for a column from mySqlDataReader by passing the name of the column in square brackets. For example mySqlDataReader CustomerID returns the value of the CustomerlD column. Step 7 displays the column values for the CustomerlD CompanyName ContactName and Address column values mySqlDataReader CustomerID mySqlDataReader CustomerID .

• Kỹ thuật lập trình
• kĩ thuật lập trình
• công nghệ thông tin
• lập trình
• ngôn ngữ lập trình
• C Shark
• C#
• sybex c
• sharp database programming
• Developing Your First ADO
• NET phần 2
• thủ thuật lập trình
• tư liệu lập trình
• hướng dẫn lập trình
• kĩ năng lập trình
• AutoIT