c# barcode generator source code Defining Tables in Visual C#.NET

Generation ECC200 in Visual C#.NET Defining Tables

Defining Tables
Print DataMatrix In Visual C#
Using Barcode printer for VS .NET Control to generate, create DataMatrix image in .NET applications.
www.OnBarcode.com
Scan Data Matrix 2d Barcode In Visual C#
Using Barcode reader for .NET Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
ow that we ve created the database, it obviously needs to have the ability to store information. After all, without this, what is the point of a database The first area that needs to be worked on is the table definitions. To be functional, a database needs at least one table, but it can have many and, depending on the solution you are building, the number of tables can become quite large. Therefore, it is important that you as a developer know as much about tables, their structures, and their contents as possible. The aim of this chapter is to teach just that, so that you have a sound base to work from regarding tables, which you can then use for the creation of other objects associated with tables. The design of a table is crucial. Each table needs to contain the correct information for its collection of columns to allow the correct relationships to be established. One of the skills of a database developer or administrator is to ensure that the final design is the correct solution, hence avoiding painful alterations once further development of the system is in progress. For example, if we designed a system where the table definitions had some major problems and required columns to be moved around, then every aspect of an application would have to be revisited. This would mean quite a large redesign. We looked at database design in 3, where we also created the database in which our tables will reside, so we know what tables we need and what data they will store. So that we can successfully create a table, this chapter will cover the following: The definition of a table The different types of data that can be stored How and where a table is stored Creating a table using SQL Server Management Studio and Query Editor Dealing with more advanced areas of table creation including How to make a row unique Special data states Dealing with pictures and large text data
Creating GS1 128 In Visual C#.NET
Using Barcode printer for .NET framework Control to generate, create GTIN - 128 image in .NET framework applications.
www.OnBarcode.com
Painting Barcode In C#
Using Barcode printer for .NET framework Control to generate, create Barcode image in Visual Studio .NET applications.
www.OnBarcode.com
CHAPTER 5 DEFINING TABLES
Creating Code 128A In C#.NET
Using Barcode creator for Visual Studio .NET Control to generate, create Code 128A image in VS .NET applications.
www.OnBarcode.com
Data Matrix ECC200 Generator In Visual C#.NET
Using Barcode generation for .NET framework Control to generate, create ECC200 image in VS .NET applications.
www.OnBarcode.com
What Is a Table
Paint QR Code In C#
Using Barcode creator for .NET Control to generate, create Denso QR Bar Code image in .NET applications.
www.OnBarcode.com
Generating 2 Of 5 Industrial In C#
Using Barcode printer for .NET framework Control to generate, create Standard 2 of 5 image in VS .NET applications.
www.OnBarcode.com
A table is a repository for data, with items of data grouped in one or more columns. Tables contain zero or more rows of information. An Excel spreadsheet can be thought of as a table, albeit a very simple table with few or no rules governing the data. If you look at Figure 5-1, you will see that the first three columns contain data that can be assumed to be first name, last name, and date of birth, but the fourth column is free-format and varies between a hotel room number, a house number, and a flat number. There is no consistency. In fact, in Excel, all the columns could in reality contain any data.
Encoding Data Matrix 2d Barcode In VS .NET
Using Barcode generation for .NET framework Control to generate, create Data Matrix 2d barcode image in Visual Studio .NET applications.
www.OnBarcode.com
Data Matrix Printer In Java
Using Barcode creator for Android Control to generate, create DataMatrix image in Android applications.
www.OnBarcode.com
Figure 5-1. Excel showing part address details What sets a table inside SQL Server apart from other potential tables is that a SQL Server table will have specific types of data held in each column, and a predetermined type of data defined for a column can never change without affecting every row of data within that column for that table. If you use Excel, in a specific column you could have a character in one row, a number in the next row, a monetary value in the following row, and so on. That cannot happen in a database table. You can store all of these different values, but they would all have to be stored as a data type that holds strings, which defeats the purpose of using a database in the first place. At the time a table is created, every column will contain a specific data type. Therefore, very careful consideration has to be made when defining a table to ensure that the column data type is the most appropriate. There is no point in selecting a generic data type (a string, for example) to cover all eventualities, as you would have to revisit the design later anyway. A table s purpose is to hold specific information. The table requires a meaningful name and one or more columns defined, each given a meaningful name and a data type; in some cases, you want to set a restriction on the maximum number of characters that the column can hold. When it comes time to create a table, you do have to be connected to SQL Server with a login that belongs to the correct server or database role that can create tables, such as sysadmin or db_ddladmin. When you create a table, it has to be owned within the database, and this is done via assigning the table to a schema. Recall 4 discusses a schema for grouping objects and as a basis for object security. Some data types have fixed storage specifications, whereas with other data types you have to decide for yourself how many characters the maximum will be. If you had a column defined for holding surnames, it would hold character values. There would also be no sense in setting the maximum length of this column at 10 characters, as many surnames are longer than this. Similarly, there would be little sense in saying the maximum should be 1,000 characters. A sensible balance has to be reached. The rows of data that will be held in a table should be related logically to each other. If a table is defined to hold customer information, then this is all it should hold. Under no circumstances should you consider putting information that was not about a customer in the table. It would be illogical to put, for example, details of customer s orders within it.
Scanning Code 39 Full ASCII In VB.NET
Using Barcode decoder for Visual Studio .NET Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
Print Barcode In VS .NET
Using Barcode generator for ASP.NET Control to generate, create Barcode image in ASP.NET applications.
www.OnBarcode.com
PDF-417 2d Barcode Decoder In C#.NET
Using Barcode decoder for Visual Studio .NET Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
Drawing Barcode In .NET
Using Barcode printer for Reporting Service Control to generate, create Barcode image in Reporting Service applications.
www.OnBarcode.com
PDF-417 2d Barcode Printer In Visual Basic .NET
Using Barcode generation for Visual Studio .NET Control to generate, create PDF417 image in Visual Studio .NET applications.
www.OnBarcode.com
Read ECC200 In VB.NET
Using Barcode recognizer for .NET framework Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
Code 128 Code Set B Drawer In .NET
Using Barcode maker for ASP.NET Control to generate, create Code 128 Code Set A image in ASP.NET applications.
www.OnBarcode.com
Creating Barcode In Objective-C
Using Barcode creation for iPhone Control to generate, create Barcode image in iPhone applications.
www.OnBarcode.com
UCC-128 Generator In None
Using Barcode encoder for Office Word Control to generate, create USS-128 image in Word applications.
www.OnBarcode.com
Encoding USS Code 39 In Objective-C
Using Barcode maker for iPhone Control to generate, create Code-39 image in iPhone applications.
www.OnBarcode.com
Copyright © OnBarcode.com . All rights reserved.