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SqlConnectionStringBuilder.ContainsKey Method

Determines whether the SqlConnectionStringBuilder contains a specific key.

Namespace:  System.Data.SqlClient
Assembly:  System.Data (in System.Data.dll)

public override bool ContainsKey(
	string keyword


Type: System.String

The key to locate in the SqlConnectionStringBuilder.

Return Value

Type: System.Boolean
true if the SqlConnectionStringBuilder contains an element that has the specified key; otherwise, false.


keyword is null (Nothing in Visual Basic)

Because the SqlConnectionStringBuilder contains a fixed-size collection of key/value pairs, the ContainsKey method determines only if a particular key name is valid.

The following example creates a SqlConnectionStringBuilder instance, sets some of its properties, and then tries to determine whether various keys exist within the object by calling the ContainsKey method.

using System.Data.SqlClient;

class Program
    static void Main()
        SqlConnectionStringBuilder builder =
            new SqlConnectionStringBuilder(GetConnectionString());
        Console.WriteLine("Connection string = " + builder.ConnectionString);

        // Keys you have provided return true.

        // Comparison is case insensitive, and synonyms 
        // are automatically converted to their "well-known" 
        // names.

        // Keys that are valid but have not been set return true.
        Console.WriteLine(builder.ContainsKey("Max Pool Size"));

        // Keys that do not exist return false.

        Console.WriteLine("Press Enter to continue.");


    private static string GetConnectionString()
        // To avoid storing the connection string in your code, 
        // you can retrieve it from a configuration file.  
        return "Server=(local);Integrated Security=SSPI;" +
            "Initial Catalog=AdventureWorks";

The example displays the following output in the console window:

Connection string = Data Source=(local);Initial Catalog=AdventureWorks;Integrated Security=True

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0