Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>Given how easy it is to replace this code, whilst removing the temptation to use dynamic SQL queries to pass parameters, I think the question should be: is there any benefit to keeping the code as-is?</p> <p>For example:</p> <pre><code>public static class Database { private static readonly Func&lt;DbCommandBuilder, int, string&gt; getParameterName = CreateDelegate("GetParameterName"); private static readonly Func&lt;DbCommandBuilder, int, string&gt; getParameterPlaceholder = CreateDelegate("GetParameterPlaceholder"); private static Func&lt;DbCommandBuilder, int, string&gt; CreateDelegate(string methodName) { MethodInfo method = typeof(DbCommandBuilder).GetMethod(methodName, BindingFlags.Instance | BindingFlags.NonPublic, Type.DefaultBinder, new Type[] { typeof(Int32) }, null); return (Func&lt;DbCommandBuilder, int, string&gt;)Delegate.CreateDelegate(typeof(Func&lt;DbCommandBuilder, int, string&gt;), method); } private static string GetDefaultProviderName() { ... } private static string GetDefaultConnectionString() { ... } public static DbProviderFactory GetProviderFactory() { string providerName = GetDefaultProviderName(); return DbProviderFactories.GetFactory(providerName); } private static DbConnection GetDBConnection(DbProviderFactory factory) { DbConnection connection = factory.CreateConnection(); connection.ConnectionString = GetDefaultConnectionString(); return connection; } public static DbConnection GetDBConnection() { DbProviderFactory factory = GetProviderFactory(); return GetDBConnection(factory); } private static void ProcessParameters( DbProviderFactory factory, DbCommand command, string query, object[] queryParameters) { if (queryParameters == null &amp;&amp; queryParameters.Length == 0) { command.CommandText = query; } else { IFormatProvider formatProvider = CultureInfo.InvariantCulture; DbCommandBuilder commandBuilder = factory.CreateCommandBuilder(); StringBuilder queryText = new StringBuilder(query); for (int index = 0; index &lt; queryParameters.Length; index++) { string name = getParameterName(commandBuilder, index); string placeholder = getParameterPlaceholder(commandBuilder, index); string i = index.ToString("D", formatProvider); command.Parameters.AddWithValue(name, queryParameters[index]); queryText = queryText.Replace("{" + i + "}", placeholder); } command.CommandText = queryText.ToString(); } } public static DataView GetDataView(string query, params object[] queryParameters) { DbProviderFactory factory = GetProviderFactory(); using (DbConnection connection = GetDBConnection(factory)) using (DbCommand command = connection.CreateCommand()) { command.CommandType = CommandType.Text; ProcessParameters(factory, command, query, queryParameters); DbDataAdapter adapter = factory.CreateDataAdapter(); adapter.SelectCommand = command; DataTable table = new DataTable(); adapter.Fill(table); return table.DefaultView; } } } </code></pre> <p>With this version, you can now pass in parameters simply and safely, without relying on custom code to try to block SQL injection:</p> <pre><code>DataView dv = Database.GetDataView( "select mycolumn from my table where id = {0} and name = {1}", 1234, "Robert');DROP TABLE Students;--"); </code></pre> <p><strong>EDIT</strong><br> Updated to support parameters for different providers, with help from <a href="https://stackoverflow.com/a/2550726/124386">this answer</a>.</p>
    singulars
    1. This table or related slice is empty.
    1. POUse of SqlDataSource From Non-Control Situations
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USCommunity
    1. USRichard Deeming
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COFYI, SqlDataSource SelectCommand (and the other commands) do not allow you to put a semicolon in your query outside of an internal string. But I do appreciate your code. It's probably doing something very similar to what SqlDataSource is doing internally.
      singulars
      1. PO
      1. USmason
    2. CO@msm8bball: Are you sure? I've just tried your code with the query `"select * from sys.databases;select * from sys.objects;"`, and it executed both commands.
      singulars
      1. PO
      1. USRichard Deeming
    3. COI tried it with System.Data.OracleClient and it gives a runtime exception. Now that I think about it, I can't recall having tried that out from SQL Server or any other data provider. Maybe that was System.Data.OracleClient specific.
      singulars
      1. PO
      1. USmason
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload