Database connection string

One: You can write directly:

String connectionString = "data Source = (local); Database = TEMP; Integrated Security = true ";

Two: can be written using SqlConnectionStringBuilder:

SqlConnectionStringBuilder builder = new SqlConnectionStringBuilder ();

Builder. DataSource = "";
Builder. InitialCatalog = "";
Builder. IntegratedSecurity = true;

String connectionString = Builder. ConnectionString;

Three: You can also write in the Web. config file:

First introduce a namespace:

Using System.Configuration;

Web. config:

<connectionStrings>
<add name= "connectionString" connectionstring= "data Source = (local); Database = TEMP; Integrated Security = True "/>
</connectionStrings>

Connection string:

String connectionString = configurationmanager.connectionstrings["connectionString"]. ConnectionString;

This method is written, you can modify the database account password at any time.

IV: Another Web. config file is written:

First, write the following code in the configuration file, Web. config, and note that the connection string is different from the original writing:

1 <connectionStrings>
2 <clear/>
3 <add name= "partialconnectstring"
4 connectionstring= "Initial catalog=northwind;"
5 providername= "System.Data.SqlClient"/>
6 </connectionStrings>

Where the ProviderName field is written, which is different from the original.

You can then write the connector in the. cs file:

You can customize a connection string method Buildconnectionstring ():

1 public string void buildconnectionstring (String datasource,string userName, String userpassword)
2 {
3 Connectionstringsettings settings =
4 configurationmanager.connectionstrings["partialconnectstring"];
5
6 if (null! = settings)
7 {
8 String connectstring = settings. ConnectionString;
9
Ten SqlConnectionStringBuilder builder =
One new SqlConnectionStringBuilder (connectstring);
12
Builder. DataSource = DataSource;
Builder. UserID = UserName;
Builder. Password = UserPassword;
Return (builder. ConnectionString);
17}
18}

Where, the data source, user name, and password are passed in. The connection string is then returned.

This is how you write a connection string using a configuration file.

V: Prevents parameter injection of the connection string:

Use SqlConnectionStringBuilder to handle the additional values inserted by the Initial Catalog settings:

1 System.Data.SqlClient.SqlConnectionStringBuilder builder = new System.Data.SqlClient.SqlConnectionStringBuilder () ;
2 builder["Data Source"] = "(local)";
3 builder["Integrated Security"] = true;
4 builder["Initial Catalog"] = "AdventureWorks; Newvalue=bad ";
5 string connectionString = Builder. ConnectionString;

Among them,; Newvalue=bad is the other string that is injected, and if it runs directly without processing, an error occurs. In this case, you can construct the link string using Builder.

Database connection string