在MSDN中，.net的数据库连接字符串都有详细的说明，我这里以代码范例的方式罗列一些，具体的每一项代表的意义可以参看MSDN.

ADO.net 中数据库连接方式(微软提供)

微软提供了以下四种数据库连接方式：
System.Data.OleDb.OleDbConnection
System.Data.SqlClient.SqlConnection
System.Data.Odbc.OdbcConnection
System.Data.OracleClient.OracleConnection
下面我们以范例的方式，来顺次说明：

System.Data.SqlClient.SqlConnection
常用的一些连接字符串(C#代码)：

SqlConnection conn
= new SqlConnection( "Server=(local);Integrated Security=SSPI;database=Pubs");

SqlConnection conn
= new SqlConnection("server=(local)\\NetSDK;database=pubs;Integrated Security=SSPI");

SqlConnection conn = new SqlConnection(
"Data Source=localhost;Integrated Security=SSPI;Initial Catalog=Northwind;");

SqlConnection conn = new SqlConnection(
" data source=(local);initial catalog=xr;integrated security=SSPI;
persist security info=False;workstation id=XURUI;packet size=4096; ");

SqlConnection myConn  = new
System.Data.SqlClient.SqlConnection("Persist Security Info=False;Integrated
Security=SSPI;database=northwind;server=mySQLServer");

SqlConnection conn = new SqlConnection(
" uid=sa;pwd=passwords;initial catalog=pubs;data source=127.0.0.1;Connect Timeout=900");

更多字符串连接说明请看MSDN：
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfSystemDataSqlClientSqlConnectionClassConnectionStringTopic.asp

System.Data.OleDb.OleDbConnection
常用的一些连接字符串(C#代码)：

OleDbConnection conn = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\MyWeb\81\05\GrocerToGo.mdb");

OleDbConnection conn = new OleDbConnection(
@"Provider=Microsoft.Jet.OLEDB.4.0;Password=;
User ID=Admin;Data Source=grocertogo.mdb;");

OleDbConnection conn = new OleDbConnection(
"Provider=MSDAORA; Data Source=ORACLE8i7;Persist Security Info=False;Integrated Security=yes");

OleDbConnection conn = new OleDbConnection(
"Provider=Microsoft.Jet.OLEDB.4.0; Data Source=c:\bin\LocalAccess40.mdb");

OleDbConnection conn = new OleDbConnection(
"Provider=SQLOLEDB;Data Source=MySQLServer;Integrated Security=SSPI");

更多字符串连接说明请看MSDN：
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfSystemDataOleDbOleDbConnectionClassConnectionStringTopic.asp?frame=true


System.Data.OracleClient.OracleConnection
常用的一些连接字符串(C#代码)：

OracleConnection myConn = new System.Data.OracleClient.OracleConnection(
"Data Source=Oracle8i;Integrated Security=yes");

 

更多字符串连接说明请看MSDN：
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfSystemDataOracleClientOracleConnectionClassConnectionStringTopic.asp?frame=true


System.Data.Odbc.OdbcConnection
常用的一些连接字符串(C#代码)：


OdbcConnection conn = new OdbcConnection(
"Driver={SQL Server};Server=MyServer;Trusted_Connection=yes;Database=Northwind;");

OdbcConnection conn = new OdbcConnection(
"Driver={Microsoft ODBC for Oracle};Server=ORACLE8i7;
Persist Security Info=False;Trusted_Connection=yes");

OdbcConnection conn = new OdbcConnection(
"Driver={Microsoft Access Driver (*.mdb)};DBQ=c:\bin\nwind.mdb");

OdbcConnection conn = new OdbcConnection(
"Driver={Microsoft Excel Driver (*.xls)};DBQ=c:\bin\book1.xls");


OdbcConnection conn = new OdbcConnection(
"Driver={Microsoft Text Driver (*.txt; *.csv)};DBQ=c:\bin");

OdbcConnection conn = new OdbcConnection("DSN=dsnname");

更多字符串连接说明请看MSDN：
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfSystemDataOdbcOdbcConnectionClassConnectionStringTopic.asp?frame=true


其他厂商提供的数据库连接：

DB2Connection myConn = new IBM.Data.DB2.DB2Connection(
"DATABASE = SAMPLE;UID=<username>; PWD=<password>;");

DB2Connection myCon