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  1. PO
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    <p>Here is the complete code of a <code>SqlHelper</code> that I'd used on some small projects. But carefull with <code>static</code> for this kind of class. If you will use it for Web project, remember that the connection will be shared at the same instance for all users, which can cause bad problems...</p> <pre><code>using System.Data; using System.Data.SqlClient; using System.Web.Configuration; public class SqlHelper { private SqlConnection connection; public SqlHelper() { connection = new SqlConnection(); } public void OpenConnection() { // Updated code getting the ConnectionString without hard naming it. // Yes, if you have more than 1 you'll have problems... But, how many times it happens? if (WebConfigurationManager.ConnectionStrings.Length == 0) throw new ArgumentNullException("You need to configure the ConnectionString on your Web.config."); else { connection.ConnectionString = WebConfigurationManager.ConnectionStrings[0].ConnectionString; connection.Open(); } } public void CloseConnection() { if (connection != null &amp;&amp; connection.State != ConnectionState.Closed) connection.Close(); } public DataTable ExecuteToDataTable(string sql) { DataTable data; SqlCommand command = null; SqlDataAdapter adapter = null; try { if (connection.State != ConnectionState.Open) OpenConnection(); command = new SqlCommand(sql, connection); adapter = new SqlDataAdapter(command); retorno = new DataTable(); adapter.Fill(data); } finally { if (command != null) command.Dispose(); if (adapter != null) adapter.Dispose(); CloseConnection(); } return data; } public int ExecuteNonQuery(string sql) { SqlCommand command = null; try { if (connection.State != ConnectionState.Open) OpenConnection(); command = new SqlCommand(sql, connection); return command.ExecuteNonQuery(); } finally { if (command != null) command.Dispose(); CloseConnection(); } } public object ExecuteScalar(string sql) { SqlCommand command = null; try { if (connection.State != ConnectionState.Open) OpenConnection(); command = new SqlCommand(sql, connection); return command.ExecuteScalar(); } finally { if (command != null) command.Dispose(); CloseConnection(); } } } </code></pre> <p>Sample usage:</p> <pre><code>SqlHelper sql = new SqlHelper(); DataTable data = sql.ExecuteToDataTable("SELECT * FROM Customers"); int affected = sql.ExecuteNonQuery("INSERT Customers VALUES ('Test')"); </code></pre> <p>But if you really want <code>static</code> (if you is on a single user enviroment), just put <code>static</code> on all methods.</p>
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    1. POWriting my own Provider Class in ASP.NET
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    1. USErick Petrucelli
    1. USErick Petrucelli
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    1. COwhile i agree with the don't make the connection static, your code still gets a known connection string from the web.config instead of some magical dynamic method.
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      1. USnathan gonzalez
    2. CO+1 Nice comments about `static` since what the OP asked can cause many troubles and what you answered is much more easy.
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    3. CO@Erick: Yes, I have similar class but with everything static and using it on more than one websites. No issues so far. The main reason I want to change it is because it has hard-coded connectionStringName (which your class has as well).
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