how to generate barcode in asp net core

asp net core 2.1 barcode generator

asp net core 2.1 barcode generator

asp net core 2.1 barcode generator

how to generate barcode in asp net core,
how to generate barcode in asp net core,
asp net core 2.1 barcode generator,
how to generate barcode in asp net core,
barcode in asp net core,
asp net core 2.1 barcode generator,
asp net core 2.1 barcode generator,
barcode in asp net core,
how to generate barcode in asp net core,
how to generate barcode in asp net core,
how to generate barcode in asp net core,
barcode in asp net core,
how to generate barcode in asp net core,
asp net core 2.1 barcode generator,
asp net core 2.1 barcode generator,
how to generate barcode in asp net core,
asp net core 2.1 barcode generator,
barcode in asp net core,
barcode in asp net core,
how to generate barcode in asp net core,
barcode in asp net core,

asp net core 2.1 barcode generator,
how to generate barcode in asp net core,
how to generate barcode in asp net core,
asp net core 2.1 barcode generator,
barcode in asp net core,
how to generate barcode in asp net core,
barcode in asp net core,
how to generate barcode in asp net core,
barcode in asp net core,
asp net core 2.1 barcode generator,
barcode in asp net core,
barcode in asp net core,
how to generate barcode in asp net core,
how to generate barcode in asp net core,
asp net core 2.1 barcode generator,
barcode in asp net core,
asp net core 2.1 barcode generator,
how to generate barcode in asp net core,
barcode in asp net core,
asp net core 2.1 barcode generator,
barcode in asp net core,
how to generate barcode in asp net core,
how to generate barcode in asp net core,
how to generate barcode in asp net core,
barcode in asp net core,
barcode in asp net core,
how to generate barcode in asp net core,
barcode in asp net core,
asp net core 2.1 barcode generator,
barcode in asp net core,
barcode in asp net core,
barcode in asp net core,
how to generate barcode in asp net core,
asp net core 2.1 barcode generator,
asp net core 2.1 barcode generator,
asp net core 2.1 barcode generator,
asp net core 2.1 barcode generator,
how to generate barcode in asp net core,
how to generate barcode in asp net core,
barcode in asp net core,
barcode in asp net core,
how to generate barcode in asp net core,
barcode in asp net core,
barcode in asp net core,
how to generate barcode in asp net core,
how to generate barcode in asp net core,
how to generate barcode in asp net core,
how to generate barcode in asp net core,

Note Now that you understand the role of ADO.NET data provider factories, the remaining examples in this book will focus on the task at hand by explicitly using the types within the System.Data.SqlClient namespace. If you use a different database management system (such as Oracle), you need to update your code base accordingly.

Recall that the connected layer of ADO.NET allows you to interact with a database using the connection, command, and data reader objects of your data provider. You have already used these objects in the previous DataProviderFactory application, now you ll walk through the process again, this time using an expanded example. You need to perform the following steps when you wish to connect to a database and read the records using a data reader object: 1. 2. 3. 4. Allocate, configure, and open your connection object. Allocate and configure a command object, specifying the connection object as a constructor argument or with the Connection property. Call ExecuteReader() on the configured command class. Process each record using the Read() method of the data reader.

The schema module also allows you to view the schema of any module. For example, Figure 5-4 shows the schema module s display of the book module s schema. Note how the table names that were in curly brackets in the table and field descriptions have been turned into helpful links.

To get the ball rolling, create a new Console Application named AutoLotDataReader and import the System.Data and System.Data.SqlClient namespaces. Here is the complete code within Main(); an analysis will follow:

class Program { static void Main(string[] args) { Console.WriteLine("***** Fun with Data Readers *****\n"); // Create an open a connection. using(SqlConnection cn = new SqlConnection()) { cn.ConnectionString = @"Data Source=(local)\SQLEXPRESS;Integrated Security=SSPI;" + "Initial Catalog=AutoLot"; cn.Open(); // Create a SQL command object. string strSQL = "Select * From Inventory"; SqlCommand myCommand = new SqlCommand(strSQL, cn); // Obtain a data reader a la ExecuteReader(). using(SqlDataReader myDataReader = myCommand.ExecuteReader()) { // Loop over the results. while (myDataReader.Read()) { Console.WriteLine("-> Make: {0}, PetName: {1}, Color: {2}.", myDataReader["Make"].ToString(), myDataReader["PetName"].ToString(), myDataReader["Color"].ToString()); } } } Console.ReadLine(); } }

The field type that is declared in the schema definition maps to a native field type in the database. For example, an integer field with the declared size of tiny becomes a TINYINT field in MySQL but a small int field in PostgreSQL. The actual map can be viewed by printing the results of getFieldTypeMap() or by looking in Table 5-1 later in this chapter.

The first step to take when working with a data provider is to establish a session with the data source using the connection object (which, as you recall, derives from DbConnection). .NET connection objects are provided with a formatted connection string; this string contains a number of name/value pairs, separated by semicolons. You use this information to identify the name of the machine you wish to connect to, required security settings, the name of the database on that machine, and other data provider specific information. As you can infer from the preceding code, the Initial Catalog name refers to the database you want to establish a session with. The Data Source name identifies the name of the machine that maintains the database. Here, (local) allows you to define a single token to specify the current local machine (regardless of the literal name of said machine), while the \SQLEXPRESS token informs the SQL server provider that you are connecting to the default SQL Server Express edition installation (if you created AutoLot on a full version of Microsoft SQL Server on your local computer, specify Data Source=(local)).

Beyond this, you can supply any number of tokens that represent security credentials. Here, you set the Integrated Security to SSPI (equivalent to true), which uses the current Windows account credentials for user authentication.