DbConnectionStringBuilder Class

Definition

Namespace:

System.Data.Common

Assembly:

System.Data.Common.dll

Source:

DbConnectionStringBuilder.cs

Provides a base class for strongly typed connection string builders.

public ref class DbConnectionStringBuilder : System::Collections::IDictionary, System::ComponentModel::ICustomTypeDescriptor

public class DbConnectionStringBuilder : System.Collections.IDictionary, System.ComponentModel.ICustomTypeDescriptor

type DbConnectionStringBuilder = class
    interface ICollection
    interface IEnumerable
    interface IDictionary
    interface ICustomTypeDescriptor

Public Class DbConnectionStringBuilder
Implements ICustomTypeDescriptor, IDictionary

Inheritance

Object

DbConnectionStringBuilder

Derived

System.Data.EntityClient.EntityConnectionStringBuilder

System.Data.Odbc.OdbcConnectionStringBuilder

System.Data.OleDb.OleDbConnectionStringBuilder

System.Data.OracleClient.OracleConnectionStringBuilder

System.Data.SqlClient.SqlConnectionStringBuilder

Implements

ICollection IDictionary IEnumerable ICustomTypeDescriptor

Examples

The following console application builds two connection strings, one for a Microsoft Jet database, and one for a SQL Server database. In each case, the code uses a generic DbConnectionStringBuilder class to create the connection string, and then passes the ConnectionString property of the DbConnectionStringBuilder instance to the constructor of the strongly typed connection class. This is not required; the code could also have created individual strongly typed connection string builder instances. The example also parses an existing connection string, and demonstrates various ways of manipulating the connection string's contents.

DbConnectionStringBuilder builder =
    new DbConnectionStringBuilder();
builder.ConnectionString = @"Data Source=c:\MyData\MyDb.mdb";
builder.Add("Provider", "Microsoft.Jet.Oledb.4.0");
// Set up row-level locking.
builder.Add("Jet OLEDB:Database Locking Mode", 1);

// The DbConnectionStringBuilder class
// is database agnostic, so it's possible to
// build any type of connection string using
// this class.

// The ConnectionString property might have been
// formatted by the DbConnectionStringBuilder class.
OleDbConnection oledbConnect = new
    OleDbConnection(builder.ConnectionString);
Console.WriteLine(oledbConnect.ConnectionString);

// Use the same DbConnectionStringBuilder to create
// a SqlConnection object.
builder.Clear();
builder.Add("integrated security", true);
builder.Add("Initial Catalog", "AdventureWorks");
builder.Add("Data Source", "(local)");

SqlConnection sqlConnect = new
    SqlConnection(builder.ConnectionString);
Console.WriteLine(sqlConnect.ConnectionString);

// Pass the DbConnectionStringBuilder an existing
// connection string, and you can retrieve and
// modify any of the elements.
builder.ConnectionString = "server=(local);initial catalog=AdventureWorks";
builder["Server"] = ".";

// Setting the indexer adds the value, if necessary.
builder["Integrated Security"] = true;
Console.WriteLine(builder.ConnectionString);

Sub Main()
    Dim builder As New DbConnectionStringBuilder()
    builder.ConnectionString = "Data Source=c:\MyData\MyDb.mdb"
    builder.Add("Provider", "Microsoft.Jet.Oledb.4.0")

    ' Set up row-level locking.
    builder.Add("Jet OLEDB:Database Locking Mode", 1)

    ' Note that the DbConnectionStringBuilder class
    ' is database agnostic, and it's possible to
    ' build any type of connection string using
    ' this class.
    ' Notice that the ConnectionString property may have been
    ' formatted by the DbConnectionStringBuilder class.

    Dim oledbConnect As New _
        OleDbConnection(builder.ConnectionString)
    Console.WriteLine(oledbConnect.ConnectionString)

    ' Use the same DbConnectionStringBuilder to create
    ' a SqlConnection object.
    builder.Clear()
    builder.Add("integrated security", True)
    builder.Add("Initial Catalog", "AdventureWorks")
    builder.Add("Data Source", "(local)")

    Dim sqlConnect As New SqlConnection(builder.ConnectionString)
    Console.WriteLine(sqlConnect.ConnectionString)

    ' Pass the DbConnectionStringBuilder an existing
    ' connection string, and you can retrieve and
    ' modify any of the elements.
    builder.ConnectionString = "server=(local);initial catalog=AdventureWorks"
    builder.Item("Server") = "."

    ' The Item property is the default for the class,
    ' and setting the Item property adds the value if
    ' necessary.
    builder("Integrated Security") = True
    Console.WriteLine(builder.ConnectionString)

    Console.WriteLine("Press Enter to finish.")
    Console.ReadLine()
End Sub

Remarks

The DbConnectionStringBuilder class provides the base class from which the strongly typed connection string builders (SqlConnectionStringBuilder, OleDbConnectionStringBuilder, and so on) derive. The connection string builders let developers programmatically create syntactically correct connection strings, and parse and rebuild existing connection strings.

The DbConnectionStringBuilder has been defined in a database-agnostic manner. Because of the addition of the System.Data.Common namespace, developers require a base class against which they can program in order to build connection strings that can work against an arbitrary database. Therefore, the DbConnectionStringBuilder class lets users assign arbitrary key/value pairs and pass the resulting connection string to a strongly typed provider. All the data providers that are included as part of .NET offer a strongly typed class that inherits from DbConnectionStringBuilder: SqlConnectionStringBuilder, OracleConnectionStringBuilder, OdbcConnectionStringBuilder, and OleDbConnectionStringBuilder.

You can build, assign, and edit connection strings for any arbitrary provider. For providers that support specific key/value pairs, the connection string builder provides strongly typed properties corresponding to the known pairs. For providers that require the ability to support unknown values, you can also supply arbitrary key/value pairs.

The DbConnectionStringBuilder class implements the ICustomTypeDescriptor interface. This means that the class works with Visual Studio designers at design time. When developers use the designer to build strongly typed DataSets and strongly typed connections within Visual Studio, the strongly typed connection string builder class displays the properties associated with its type and also has converters that can map common values for known keys.

If you need to create connection strings as part of applications, use the DbConnectionStringBuilder class or one of its strongly typed derivatives to build and modify connection strings. The DbConnectionStringBuilder class also makes it easy to manage connection strings stored in an application configuration file.

You can create connection strings using either a strongly typed connection string builder class or the DbConnectionStringBuilder class. The DbConnectionStringBuilder performs no checks for valid key/value pairs. Therefore, it's possible to create invalid connection strings when using this class. The SqlConnectionStringBuilder supports only key/value pairs that are supported by SQL Server; trying to add invalid pairs will throw an exception.

Both the Add method and Item[] property handle cases where a bad actor tries to insert malicious entries. For example, the following code correctly escapes the nested key/value pair:

Dim builder As New System.Data.Common.DbConnectionStringBuilder
builder("Data Source") = "(local)"
builder("integrated sSecurity") = True
builder("Initial Catalog") = "AdventureWorks;NewValue=Bad"

System.Data.Common.DbConnectionStringBuilder builder = new System.Data.Common.DbConnectionStringBuilder();
builder["Data Source"] = "(local)";
builder["integrated Security"] = true;
builder["Initial Catalog"] = "AdventureWorks;NewValue=Bad";

The result is the following connection string that handles the invalid value in a safe manner:

data source=(local);integrated security=True;
initial catalog="AdventureWorks;NewValue=Bad"

Constructors

DbConnectionStringBuilder()	Initializes a new instance of the DbConnectionStringBuilder class.
DbConnectionStringBuilder(Boolean)	Initializes a new instance of the DbConnectionStringBuilder class, optionally using ODBC rules for quoting values.

Properties

BrowsableConnectionString	Gets or sets a value that indicates whether the ConnectionString property is visible in Visual Studio designers.
ConnectionString	Gets or sets the connection string associated with the DbConnectionStringBuilder.
Count	Gets the current number of keys that are contained within the ConnectionString property.
IsFixedSize	Gets a value that indicates whether the DbConnectionStringBuilder has a fixed size.
IsReadOnly	Gets a value that indicates whether the DbConnectionStringBuilder is read-only.
Item[String]	Gets or sets the value associated with the specified key.
Keys	Gets an ICollection that contains the keys in the DbConnectionStringBuilder.
Values	Gets an ICollection that contains the values in the DbConnectionStringBuilder.

Methods

Add(String, Object)	Adds an entry with the specified key and value into the DbConnectionStringBuilder.
AppendKeyValuePair(StringBuilder, String, String)	Provides an efficient and safe way to append a key and value to an existing StringBuilder object.
AppendKeyValuePair(StringBuilder, String, String, Boolean)	Provides an efficient and safe way to append a key and value to an existing StringBuilder object.
Clear()	Clears the contents of the DbConnectionStringBuilder instance.
ClearPropertyDescriptors()	Clears the collection of PropertyDescriptor objects on the associated DbConnectionStringBuilder.
ContainsKey(String)	Determines whether the DbConnectionStringBuilder contains a specific key.
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
EquivalentTo(DbConnectionStringBuilder)	Compares the connection information in this DbConnectionStringBuilder object with the connection information in the supplied object.
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetProperties(Hashtable)	Fills a supplied Hashtable with information about all the properties of this DbConnectionStringBuilder.
GetType()	Gets the Type of the current instance. (Inherited from Object)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
Remove(String)	Removes the entry with the specified key from the DbConnectionStringBuilder instance.
ShouldSerialize(String)	Indicates whether the specified key exists in this DbConnectionStringBuilder instance.
ToString()	Returns the connection string associated with this DbConnectionStringBuilder.
TryGetValue(String, Object)	Retrieves a value corresponding to the supplied key from this DbConnectionStringBuilder.

Explicit Interface Implementations

ICollection.CopyTo(Array, Int32)	Copies the elements of the ICollection to an Array, starting at a particular Array index.
ICollection.IsSynchronized	Gets a value indicating whether access to the ICollection is synchronized (thread safe).
ICollection.SyncRoot	Gets an object that can be used to synchronize access to the ICollection.
ICustomTypeDescriptor.GetAttributes()	Returns a collection of custom attributes for this instance of a component.
ICustomTypeDescriptor.GetClassName()	Returns the class name of this instance of a component.
ICustomTypeDescriptor.GetComponentName()	Returns the name of this instance of a component.
ICustomTypeDescriptor.GetConverter()	Returns a type converter for this instance of a component.
ICustomTypeDescriptor.GetDefaultEvent()	Returns the default event for this instance of a component.
ICustomTypeDescriptor.GetDefaultProperty()	Returns the default property for this instance of a component.
ICustomTypeDescriptor.GetEditor(Type)	Returns an editor of the specified type for this instance of a component.
ICustomTypeDescriptor.GetEvents()	Returns the events for this instance of a component.
ICustomTypeDescriptor.GetEvents(Attribute[])	Returns the events for this instance of a component using the specified attribute array as a filter.
ICustomTypeDescriptor.GetProperties()	Returns the properties for this instance of a component.
ICustomTypeDescriptor.GetProperties(Attribute[])	Returns the properties for this instance of a component using the attribute array as a filter.
ICustomTypeDescriptor.GetPropertyOwner(PropertyDescriptor)	Returns an object that contains the property described by the specified property descriptor.
IDictionary.Add(Object, Object)	Adds an element with the provided key and value to the IDictionary object.
IDictionary.Contains(Object)	Determines whether the IDictionary object contains an element with the specified key.
IDictionary.GetEnumerator()	Returns an IDictionaryEnumerator object for the IDictionary object.
IDictionary.Item[Object]	Gets or sets the element with the specified key.
IDictionary.Remove(Object)	Removes the element with the specified key from the IDictionary object.
IEnumerable.GetEnumerator()	Returns an enumerator that iterates through a collection.

Extension Methods

Cast<TResult>(IEnumerable)	Casts the elements of an IEnumerable to the specified type.
OfType<TResult>(IEnumerable)	Filters the elements of an IEnumerable based on a specified type.
AsParallel(IEnumerable)	Enables parallelization of a query.
AsQueryable(IEnumerable)	Converts an IEnumerable to an IQueryable.

See also

• Connection Strings in ADO.NET
• ADO.NET Overview