C# SQL SELECT - SQL

Are you looking for a tutorial on how to perform a SELECT statement in C# using SQL? Then you're in the right place!

In this guide, we will cover the basic syntax of a SELECT statement in SQL and how to execute it in C# using ADO.NET.

Basic Syntax of a SELECT Statement in SQL

The basic syntax of a SELECT statement in SQL is:

SELECT column1, column2, ...
FROM table_name
WHERE condition;

Here:

• column1, column2, ...: the column(s) you want to retrieve data from
• table_name: the name of the table you want to retrieve data from
• condition: the condition(s) that must be met for the data to be retrieved (optional)

Executing a SELECT Statement in C# Using ADO.NET

To execute a SELECT statement in C# using ADO.NET, you need to follow these steps:

1. Create a SqlConnection object and set the connection string.

   SqlConnection conn = new SqlConnection("Data Source=myServerAddress;Initial Catalog=myDataBase;User ID=myUsername;Password=myPassword;");
   

2. Open the connection to the database.

   conn.Open();
   

3. Create a SqlCommand object and set the SELECT statement.

   SqlCommand cmd = new SqlCommand("SELECT column1, column2 FROM table_name WHERE condition", conn);
   

4. Execute the SELECT statement and retrieve the data using a SqlDataReader object.

   SqlDataReader dr = cmd.ExecuteReader();
   

5. Loop through the data using the Read() method of the SqlDataReader object.

   while (dr.Read())
   {
       // retrieve data using the column names or indices
       string column1Value = dr["column1"].ToString();
       string column2Value = dr[1].ToString();
   }
   

6. Close the SqlDataReader object and the connection.

   dr.Close();
   conn.Close();
   

Conclusion

In this guide, we have learned the basic syntax of a SELECT statement in SQL and how to execute it in C# using ADO.NET. With this knowledge, you can now retrieve data from a database using C# and SQL. Happy coding!