ADO.NET Entity Framework 数据库连接字符串手工设置

一般情况，可以直接使用系统自动配置的连接字符串。如果要发布或者多个数据源，则

需要手工设置数据库连接。  示例如下：

 // Specify the provider name, server and database.

            string providerName = "System.Data.SqlClient";
            string serverName = "DBServer";
            string databaseName = "databaseName";

            // Initialize the connection string builder for the
            // underlying provider.
            SqlConnectionStringBuilder sqlBuilder =
                new SqlConnectionStringBuilder();

            // Set the properties for the data source.
            sqlBuilder.DataSource = serverName;
            sqlBuilder.InitialCatalog = databaseName;
            sqlBuilder.IntegratedSecurity = false;
            sqlBuilder.UserID = "sa";
            sqlBuilder.Password = "sa";

            // Build the SqlConnection connection string.
            string providerString = sqlBuilder.ToString();

            // Initialize the EntityConnectionStringBuilder.
            EntityConnectionStringBuilder entityBuilder =
                new EntityConnectionStringBuilder();

            //Set the provider name.
            entityBuilder.Provider = providerName;

            // Set the provider-specific connection string.

            entityBuilder.ProviderConnectionString = providerString;

            entityBuilder.Provider = providerName;

            // Set the Metadata location.
            entityBuilder.Metadata = "res://*" ; //或从.config文件中copy
                            //@"res://*/NBModel.csdl|
                            //res://*/NBModel.ssdl|
                            //res://*/NBModel.msl";
            string str = entityBuilder.ToString();

            using (NORTHWNDEntities nwt = new NORTHWNDEntities( entityBuilder.ToString()))
            {
                var query = from cat in nwt.Categories
                            select cat;
                this.GridView1.DataSource = query;
                this.GridView1.DataBind();

            }