DbConnectionStringBuilder Class

DbConnectionStringBuilder Class


Provides a base class for strongly typed connection string builders.

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

public class DbConnectionStringBuilder : IDictionary, ICollection, 
	IEnumerable, ICustomTypeDescriptor


Initializes a new instance of the DbConnectionStringBuilder class.


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


Gets or sets a value that indicates whether the ConnectionString property is visible in Visual Studio designers.


Gets or sets the connection string associated with the DbConnectionStringBuilder.


Gets the current number of keys that are contained within the ConnectionString property.


Gets a value that indicates whether the DbConnectionStringBuilder has a fixed size.


Gets a value that indicates whether the DbConnectionStringBuilder is read-only.


Gets or sets the value associated with the specified key.


Gets an ICollection that contains the keys in the DbConnectionStringBuilder.


Gets an ICollection that contains the values in the DbConnectionStringBuilder.

System_CAPS_pubmethodAdd(String, Object)

Adds an entry with the specified key and value into the DbConnectionStringBuilder.

System_CAPS_pubmethodSystem_CAPS_staticAppendKeyValuePair(StringBuilder, String, String)

Provides an efficient and safe way to append a key and value to an existing StringBuilder object.

System_CAPS_pubmethodSystem_CAPS_staticAppendKeyValuePair(StringBuilder, String, String, Boolean)

Provides an efficient and safe way to append a key and value to an existing StringBuilder object.


Clears the contents of the DbConnectionStringBuilder instance.


Clears the collection of PropertyDescriptor objects on the associated DbConnectionStringBuilder.


Determines whether the DbConnectionStringBuilder contains a specific key.


Determines whether the specified object is equal to the current object.(Inherited from Object.)


Compares the connection information in this DbConnectionStringBuilder object with the connection information in the supplied object.


Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)


Serves as the default hash function. (Inherited from Object.)


Fills a supplied Hashtable with information about all the properties of this DbConnectionStringBuilder.


Gets the Type of the current instance.(Inherited from Object.)


Creates a shallow copy of the current Object.(Inherited from Object.)


Removes the entry with the specified key from the DbConnectionStringBuilder instance.


Indicates whether the specified key exists in this DbConnectionStringBuilder instance.


Returns the connection string associated with this DbConnectionStringBuilder.(Overrides Object.ToString().)

System_CAPS_pubmethodTryGetValue(String, Object)

Retrieves a value corresponding to the supplied key from this DbConnectionStringBuilder.

System_CAPS_pubinterfaceSystem_CAPS_privmethodICollection.CopyTo(Array, Int32)

Copies the elements of the ICollection to an Array, starting at a particular Array index.

System_CAPS_pubinterfaceSystem_CAPS_privmethodIDictionary.Add(Object, Object)

Adds an element with the provided key and value to the IDictionary object.


Determines whether the IDictionary object contains an element with the specified key.


Returns an IDictionaryEnumerator object for the IDictionary object.


Removes the element with the specified key from the IDictionary object.


Returns an enumerator that iterates through a collection.


Returns a collection of custom attributes for this instance of a component.


Returns the class name of this instance of a component.


Returns the name of this instance of a component.


Returns a type converter for this instance of a component.


Returns the default event for this instance of a component.


Returns the default property for this instance of a component.


Returns an editor of the specified type for this instance of a component.


Returns the events for this instance of a component.


Returns the events for this instance of a component using the specified attribute array as a filter.


Returns the properties for this instance of a component.


Returns the properties for this instance of a component using the attribute array as a filter.


Returns an object that contains the property described by the specified property descriptor.


Overloaded. Enables parallelization of a query.(Defined by ParallelEnumerable.)


Overloaded. Converts an IEnumerable to an IQueryable.(Defined by Queryable.)


Casts the elements of an IEnumerable to the specified type.(Defined by Enumerable.)


Filters the elements of an IEnumerable based on a specified type.(Defined by Enumerable.)

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 the .NET Framework provide a strongly typed class that inherits from DbConnectionStringBuilder: SqlConnectionStringBuilder, OracleConnectionStringBuilder, OdbcConnectionStringBuilder, and OleDbConnectionStringBuilder.

The developer 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. In order to support providers that require the ability to support unknown values, developers 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 will display the properties associated with its type and will also have converters that can map common values for known keys.

Developers needing to create connection strings as part of applications can 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.

Developers can create connection strings using either a strongly typed connection string builder class, or they can use the DbConnectionStringBuilder class. The DbConnectionStringBuilder performs no checks for valid key/value pairs. Therefore, it is possible using this class to create invalid connection strings. 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 tries to insert malicious entries. For example, the following code correctly escapes the nested key/value pair:

[Visual Basic]

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"

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 type 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.

static void Main()
    DbConnectionStringBuilder builder =
        new DbConnectionStringBuilder();
    builder.ConnectionString = @"Data Source=c:\MyData\MyDb.mdb";
    builder.Add("Provider", "Microsoft.Jet.Oledb.4.0");
    builder.Add("Jet OLEDB:Database Password", "*******");
    builder.Add("Jet OLEDB:System Database",
    // 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 may have been 
    // formatted by the DbConnectionStringBuilder class.
    OleDbConnection oledbConnect = new

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

    SqlConnection sqlConnect = new

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

    // Note that calling Remove on a nonexistent item doesn't
    // throw an exception.

    // Setting the indexer adds the value if 
    // necessary.
    builder["Integrated Security"] = true;
    builder["User ID"] = "Hello";

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

Universal Windows Platform
Available since 10
.NET Framework
Available since 2.0

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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