Using dotConnect Universal with SQL Client

In This Topic

This article provides a brief overview of using dotConnect Universal with the .NET Framework Data Provider for SQL Server, describes some useful features and helps you get started quickly.

Overview
Compatibility
Deployment
Typical Connection String
Quick Start Steps
Special Features
UniSQL Notes
UniDbType Map
Additional Information

Overview

The .NET Framework Data Provider for SQL Server is a standard 100% managed ADO.NET data provider for the .NET Framework. It is preinstalled with every version of the .NET Framework and the .NET Compact Framework, so you can be sure that the SQL Client is always available. For more information about the data provider refer to MSDN documentation.

Compatibility

dotConnect Universal is compatible with SQL Client version 1.05 and above. dotConnect Universal automatically uses SQL Client from appropriate .NET Framework.

Deployment

To deploy applications written with dotConnect Universal, copy the run-time assembly Devart.Data.Universal.dll to target machine. This assembly can be registered at the Global Assembly Cache (GAC) for the appropriate .NET Framework or placed in the folder of your application.

For web projects, you may also need to deploy the Devart.Data.Universal.Web.dll and App_Licenses.dll assemblies. The Devart.Data.Universal.Web.dll assemblies are required for using the ASP.NET Provider Model, and the App_Licenses.dll assembly is a part of licensing mechanism.

Web projects are usually run as partially trusted code. dotConnect Universal requires ReflectionPermission in addition to the medium trust level

Connection String

Suppose you want to connect to a SQL Server running on the host myserver, with the user name sa and the password mypassword. Suppose also that you would like to choose Northwind as the default database. In this case your connection string would look like this:

Provider=SQL Server;server=myserver;user id=sa;password=mypassword;initial catalog=Northwind

The following table enumerates most important connection string parameters.

Name	Default	Description
Application Name	N/A	The name of the application, or '.NET SQLClient Data Provider' if no application name is provided.
Asynch	'false'	When true, enables asynchronous operation support. Recognized values are true, false, yes, and no.
AttachDBFilename -or- extended properties -or- Initial File Name	N/A	The name of the primary database file, including the full path name of an attachable database. The path may be absolute or relative by using the DataDirectory substitution string. If DataDirectory is used, the database file must exist within a subdirectory of the directory pointed to by the substitution string. The database name must be specified with the keyword 'database' (or one of its aliases) as in the following: `"AttachDbFileName=\|DataDirectory\|\data\YourDB.mdf;integrated security=true;database=YourDatabase"`
Connect Timeout -or- Connection Timeout	15	The length of time (in seconds) to wait for a connection to the server before terminating the attempt and generating an error.
Context Connection	'false'	true if an in-process connection to SQL Server should be made.
Current Language	N/A	The SQL Server Language record name.
Data Source -or- Server -or- Address -or- Addr -or- Network Address	N/A	The name or network address of the instance of SQL Server to which to connect. The port number can be specified after the server name: `server=tcp:servername, portnumber` When specifying a local instance, always use (local). To force a protocol, add one of the following prefixes: `np:(local), tcp:(local), lpc:(local)`
Encrypt	'false'	When true, SQL Server uses SSL encryption for all data sent between the client and server if the server has a certificate installed. Recognized values are true, false, yes, and no.
Enlist	'false'	true indicates that the SQL Server connection pooler automatically enlists the connection in the creation thread's current transaction context.
Failover Partner	N/A	The name of the failover partner server where database mirroring is configured. The Failover Partner keyword is not supported by .NET Framework version 1.0 or 1.1.
Initial Catalog -or- Database	N/A	The name of the database.
Integrated Security -or- Trusted_Connection	'false'	When false, User ID and Password are specified in the connection. When true, the current Windows account credentials are used for authentication. Recognized values are true, false, yes, no, and sspi (strongly recommended), which is equivalent to true.
MultipleActiveResultSets	'true'	When true, an application can maintain multiple active result sets (MARS). When false, an application must process or cancel all result sets from one batch before it can execute any other batch on that connection. Recognized values are true and false. The keyword is not supported by .NET Framework version 1.0 or 1.1.
Network Library -or- Net	'dbmssocn'	The network library used to establish a connection to an instance of SQL Server. Supported values include dbnmpntw (Named Pipes), dbmsrpcn (Multiprotocol), dbmsadsn (Apple Talk), dbmsgnet (VIA), dbmslpcn (Shared Memory) and dbmsspxn (IPX/SPX), and dbmssocn (TCP/IP). The corresponding network DLL must be installed on the system to which you connect. If you do not specify a network and you use a local server (for example, "." or "(local)"), shared memory is used.
Packet Size	8192	Size in bytes of the network packets used to communicate with an instance of SQL Server.
Password -or- Pwd	N/A	The password for the SQL Server account logging on. Not recommended. To maintain a high level of security, we strongly recommend that you use the Integrated Security or Trusted_Connection keyword instead.
Persist Security Info	'false'	When set to false or no (strongly recommended), security-sensitive information, such as the password, is not returned as part of the connection if the connection is open or has ever been in an open state. Resetting the connection string resets all connection string values including the password. Recognized values are true, false, yes, and no.
Replication	'false'	true if replication is supported using the connection.
TrustServerCertificate	'false'	When set to true, SSL is used to encrypt the channel but to bypass walking the certificate chain to validate trust. If the connection string has TrustServerCertificate set to true but Encrypt is not set to true, the channel is not encrypted. Recognized values are true, false, yes, and no. For more information, see "Encryption Hierarchy" and "Using Encryption Without Validation" in SQL Server 2005 Books Online.
Type System Version	N/A	A string value that indicates the type system the application expects. Possible values are: `Type System Version=SQL Server 2000;` `Type System Version=SQL Server 2005;` `Type System Version=Latest;` When set to SQL Server 2000, the SQL Server 2000 type system is used. The following conversions are performed when connecting to a SQL Server 2005 instance: XML to NTEXT UDT to VARBINARY VARCHAR(MAX), NVARCHAR(MAX) and VARBINARY(MAX) to TEXT, NEXT and IMAGE respectively. When set to SQL Server 2005, the SQL Server 2005 type system is used. No conversions are made for the current version of ADO.NET. When set to Latest, the latest version than this client-server pair can handle is used. This will automatically move forward as the client and server components are upgraded.
User ID	N/A	The SQL Server login account. Not recommended. To maintain a high level of security, we strongly recommend that you use the Integrated Security or Trusted_Connection keywords instead.
User Instance	'false'	A value that indicates whether to redirect the connection from the default SQL Server Express instance to a runtime-initiated instance running under the account of the caller.
Workstation ID	The local computer name	The name of the workstation connecting to SQL Server.

The following table lists the valid names for connection pooling values within the ConnectionString.

Name	Default	Description
Connection Lifetime	0	When a connection is returned to the pool, its creation time is compared with the current time, and the connection is destroyed if that time span (in seconds) exceeds the value specified by Connection Lifetime. This is useful in clustered configurations to force load balancing between a running server and a server just brought online. A value of zero (0) causes pooled connections to have the maximum connection timeout.
Connection Reset	'true'	Determines whether the database connection is reset when being drawn from the pool. For SQL Server version 7.0, setting to false avoids making an additional server round trip when obtaining a connection, but you must realize that the connection state, such as database context, is not being reset. The connection pooler is not influenced by the ChangeDatabase method as long you do not set Connection Reset to false. As the connection comes out of the pool the connection is reset with the server moving back to the login time database. There are no new connections created or reauthentications. If you set Connection Reset to false, connections in the pool to different databases might result.
Enlist	'true'	When true, the pooler automatically enlists the connection in the creation thread's current transaction context. Recognized values are true, false, yes, and no.
Load Balance Timeout	0	The minimum time, in seconds, for the connection to live in the connection pool before being destroyed.
Max Pool Size	100	The maximum number of connections allowed in the pool.
Min Pool Size	0	The minimum number of connections allowed in the pool.
Pooling	'true'	When true, the SQLConnection object is drawn from the appropriate pool, or if it is required, is created and added to the appropriate pool. Recognized values are true, false, yes, and no.

Quick Start Steps

To get up and running quickly, you have to perform the following steps:

Embed dotConnect Universal licensing information into your application. For more details on licensing refer to the Licensing article. It may be enough to drop a UniConnection component onto a form designer to embed the licensing information.
Create a UniConnection object.
Set the ConnectionString property of the UniConnection object to a string containing the part Provider=SQL Server.
Create a UniCommand object and link it to the UniConnection object.
Open the connection.

That's all you need to start executing queries on the server. Below is a code fragment that illustrates steps 2-5. It also shows how to perform INSERT and SELECT operations.

UniConnection connection = new UniConnection("Provider=SQL Server;server=myserver;user id=sa;password=mypassword;initial catalog=Northwind");
try {
  UniCommand cmd = connection.CreateCommand();
  cmd.CommandText = "INSERT INTO dept (DeptNo, Dname, Loc) VALUES (:DeptNo, :DName, :Loc)";
  UniParameter parameter = cmd.Parameters.Add("DeptNo", UniDbType.Int);
  parameter.Value = 150;
  parameter = cmd.Parameters.Add("DName", UniDbType.VarChar);
  parameter.Value = "DEPTNAME";
  cmd.Parameters.Add(parameter);
  parameter = cmd.Parameters.Add("Loc", UniDbType.VarChar);
  parameter.Value = "LOCATION";
  cmd.Parameters.Add(parameter);
  connection.Open();
  cmd.ExecuteNonQuery();
}
finally {
  connection.Close();
}

...

DataSet dataSet = new DataSet();
UniDataAdapter da = new UniDataAdapter("SELECT * FROM dept", "Provider=SQL Server;server=myserver;user id=sa;password=mypassword;initial catalog=Northwind");
da.Fill(dataSet, "Dept");

Visual Basic


Dim connection As Devart.Data.Universal.UniConnection = New _
  Devart.Data.Universal.UniConnection("Provider=SQL Server;server=myserver;user id=sa;password=mypassword;initial catalog=Northwind")
Try
  Dim cmd As UniCommand = connection.CreateCommand()
  cmd.CommandText = "INSERT INTO dept (DeptNo, DName, Loc) VALUES (:DeptNo, :DName, :Loc)"
  Dim parameter As Devart.Data.Universal.UniParameter = cmd.Parameters.Add("DEPTNO", UniDbType.Int)
  parameter.Value = 150
  parameter = cmd.Parameters.Add("DName", UniDbType.VarChar)
  parameter.Value = "DEPTNAME"
  parameter = cmd.Parameters.Add("Loc", UniDbType.VarChar)
  parameter.Value = "LOCATION"
  connection.Open()
  cmd.ExecuteNonQuery()
Finally
  connection.Close()
End Try

...

Dim dataSet As DataSet = New DataSet()
Dim da As UniDataAdapter = New UniDataAdapter("Provider=SQL Server;server=myserver;user id=sa;password=mypassword;initial catalog=Northwind")
da.Fill(dataSet, "Dept")

Special Features

dotConnect Universal supports handling SQL Server BLOBs. For detailed information on how to work with BLOB objects, refer to the Working with BLOB Data article.

dotConnect Universal supports the SQL Server DECIMAL type. Use the UniDecimal structure reference to find out how to manage big numbers on client side.

Note that SQL Server does not support INTERVAL database types. However, in most cases this restriction can be compensated with DateAdd and DateDiff functions.

UniSQL Notes

SQL Client supports all features of UniSQL. Use SQL Server and SQLClient predefined macros to build conditional UniSQL statements. For more information refer to the UniSQL topic.

UniDbType Map

The following table shows how the UniDbType enumeration maps to the SQL Server database type.

UniDbType	SQL Server Type
BigInt	BIGINT
Binary	BINARY
Bit	BIT
Blob	IMAGE
Boolean	BIT
Byte	SMALLINT
Char	CHAR
Clob	TEXT
Currency	DOUBLE
Date	DATETIME
DateTime	DATETIME
DateTime2	DATETIME2
Decimal	DECIMAL
Double	REAL
Guid	UNIQUEIDENTIFIER
Int	INT
NChar	NCHAR
NClob	NTEXT
NVarChar	NVARCHAR
Single	FLOAT
SmallInt	SMALLINT
TinyInt	TINYINT
Time	DATETIME
TimeStamp	DATETIME
VarChar	VARCHAR

Additional Information

For more information on the .NET Framework Data Provider for SQL Server refer to MSDN.