Varchar is dynamic and char takes the number of bytes it defined, irrespective of size used.
SQL Update is a command or updating a data record. SQL Update query is part of the SQL standard that is implemented by all product vendors. Thus, the concept applies uniformly across all RDBMS products. Typically, in an RDBMS based database, data is organized as rows and columns. Each row of data has fields in columns that are related. One row of data is called a record. SQL Update is a means of updating a field within a record in the database. The syntax of SQL Update command provides for specifying the particular piece of data into a database table.
The following is the syntax for the SQL Update command. The words in capitals are the keywords that must be used as is. The text strings within quote marks in the syntax of SQL Update query indicated need to be filled by actual parameter values for pinpointing the specific items to be updated.
UPDATE [table name]
SET [column name1]= ‘column value1′
WHERE [a particular column name]=’existing value of the column’
This above syntax of SQL Update specifies a specific table name on which data updates are to be made. The SET keyword lets the user specify the new values to be created in the given fields/columns of the table. The WHERE keyword specifies the existing value of a keyword so that the particular record can be pinpointed. In the absence of the WHERE keyword in the SQL UPDATE syntax, all the records will get updated. Let us follow this with an example so that the exact meaning is very apparent.
A phone book is something every one of us use. If a typical phonebook was implemented in an RDBMS a table “PhoneDirectory” could look something like the table indicated below.
A simple table like this could be updated manually. When the phone book is large, for example, the public phone book for the organization, updating will need database support. One of the most common changes that can happen is that the person may have switched over to another company. His or her work phone or home phone could change. SQL UPDATE statement provides the means to make a change to the database, specifically to a particular record in the database.
For the sake of illustrating the use of the SQL UPDATE, let us assume Robert Halden has been transferred to a different city where the ABC, Inc. has an office. In such a case both his work and home phones would change. SQL UPDATE command for making these desired changes would look like the following.
SET WorkPhonenumber=’397-478-2294′, HomePhoneNumber=’397-225-8325′
WHERE ContactName=’Robert Halden’
This SQL UPDATE statement chooses the right table in a database and substitutes the work and home phone numbers of a specific record where the contact name is Robert Halden. The update happens in just one record that is required to be updated. If some particular column value(s) for all records were to be updated, dropping the WHERE clause of the SQL UPDATE command would do the job. The SET clause will specify the column and the value to be set in the complete database.
What a database is simply a repository of data. Data are pieces of information that is important for some purpose; business or otherwise. Typically, you would need to add to the repository, pieces of data may need to be updated/ modified. When a piece of data has outlived its purpose, users would like to delete the same. A software system that lets you manage data and meet your needs as described is a Database. Examples of databases we are familiar with would be,
RDMS or relational databases are in popular use for storing such data in an enterprise. These use an organization known as tables. These tables themselves are organized in a manner familiar to all of us as rows of information that has columns to store related pieces of data for that row. Tabular organization helps searching flexibly. Relational databases allow relating multiple tables together for the data finding and manipulation purposes. This is something we do at personal levels too. Our telephone book is a prime example of this organization. A name with first name and second name, telephone number, possibly the address goes into such a phone book. Often important dates like birthday, wedding anniversary and other information are included. One such entry will be a record in a particular database row. Each of the items will go into a column that is common to all the records. Some well-known and popular databases are Oracle, SQL Server and MySQL.
Sometimes the database may be organized in a distributed manner. The data are placed at different physical locations and parts of the database may have copies at different spots on the network.
An associated concept to a database is a database management system. These database products let you store multiple databases and have very large capacities to do so. In a typical business, you may need to store data about customers, sales made, details of your inventory and so on. There is a need for a management process to let the diverse databases work properly. The DBMS or the database management system lets read or write access in a disciplined manner. Authorization of users is managed by the system. Analysis of usage and performance are also provided. Then, of course necessary types of reports are usually provided by these database management systems.
Database and database managers are available on the full spectrum of systems; from mainframes to personal computers and everything in between. Major difference is in the capability of the amount of data that could be handled by the different versions of each product. In all these incarnations of the database products, it is the relational database that is currently used predominantly. All the products use a form of a query language that has become an ANSI as well as ISO standard. This is known as Structured Query language or SQL. This language lets the users specify queries to find data, manipulate or update them. It has commands for changing the structure of the database too.
The Microsoft RDBMS product SQL Server is available in several editions. The most common ones are the Express, Standard and the Enterprise editions. Standard versions of each release will have more features and capabilities than the Express version. SQL Server Enterprise edition, in turn, has more capability than the standard editions of each release. Depending on the release version of the product, there may be additional versions.
For example, the 2012 release has a business intelligence edition. We shall concentrate on this latest product here, the SQL Server 2012 Enterprise version. While the Express edition is for familiarization, the SQL Server Enterprise is for serous applications like implementing high capability data centers with extensive database and business intelligence solutions.
Some of the notable features of the SQL Server Enterprise edition 2012 include the following:
The huge amounts of data that gets generated today needs to be managed and stored. One never knows what kind of insight is available from the big data collection. Besides the efficient storage and management implemented in SQL Server Enterprise edition, it ensures the ability to view the data to discern any valuable patterns. An additional tool of Power Pivot in the Power View feature of the SQL Enterprise version helps users to access and combine data from other sources to derive meaning to data visualizations being made. Support of cleansing of data helps the IT department to ensure BI solutions that are dependable. There will be no need to drill down to low-level data to ensure they are good data.
Whenever a new version of a product arrives on the scene, a question that arises without fail is whether existing users should upgrade. ROI percentage and the time it takes to recoup the investment are good metrics to help you decide. According to a Forrester study commissioned by Microsoft for an upgrade to SQL Server Enterprise 2012 has indicated that ROI percentage is 189%, and the payback time is just one year. In order to learn more, check out SQL Server 2012 Training.
Microsoft released their product SQL Server 2008 r2 in 2010. As it is usual with their products, MS SQL Server 2008 R2 also has an Express edition that is available for evaluation and use in small systems. Microsoft SQL Server 2008 r2 is available in Standard and Enterprise editions. Having tried out the SQL Server 2008 r2 Express, you would eventually graduate to either the standard or the Enterprise editions depending on your actual needs. Two other special editions also were released with the MS SQL Server 2008 R2. These are the SQL Server 2008 R2 Datacenter and SQL Server 2008 R2 Parallel Data Warehouse. These two special editions were introduced to meet increasing demands for datacenters and parallel data warehouse applications (Business Intelligence applications).
As with other versions, Microsoft SQL Server 2008 R2 Express edition is supplied free by Microsoft. This facilitates your team becoming familiar with the database product, get used to developing web based and desktop applications, etc. You will need the help of Microsoft Visual Studio and Visual Web Developer Express.
Some features added over the MS SQL Server 2008 R2 include the following:
For getting started with the 2008 R2 you need to download the Express edition first. It is fairly simple to download and install. It is free to use, but you will need to get the product registered with Microsoft. Your team can start getting familiar with it right away. When the team gets into applications development activities, there is another issue you need to take into account. All such database applications need to have the database as part of the application and then the question is if you can re-distribute the database to a third party (your customer). This too is free for the Express edition, but you will have to apply and get the right approved by Microsoft.
The so-called core editions of Enterprise and Standard are the most popular ones of the SQL Server 2008 R2 product. The SQL Server 2008 R2 Standard is positioned as the database tool for data management as well as business intelligence for departments and also the small and medium business segment. This configuration is supposed to take up minimum of IT resources. Some new features in the Standard edition are:
The SQL Server 2008 R2 Enterprise is capable of delivering a data platform but provides the user a secure, highly available and scalable product. Business intelligence features are supported. Some new features in the Enterprise edition include:
The Microsoft SQL 2008 R2 also offers a free Compact edition for applications on mobile devices besides desktop and the web.
In simple terms, database management software is a set of software tools that help manage databases. To understand other functions of database management software, one needs to look at what databases are and what they do? Databases are repositories of data. Business and other applications access this data, manipulate/modify it and store it back or may even delete the data records. How the data is organized internally affects how effectively and efficiently data could be found and manipulated. This structure or the arrangement of data inside a database has evolved over time. From hierarchical and networked models, most database today are relational. Data in these relational databases are organized in a tabular fashion. Database management software will make sure such structures are maintained properly. This organization is much like the spreadsheet kind of arrangement like Microsoft Excel. Each row has information or data items that are related to the information contained in the row or record. Most of us are familiar with phone books and they are typically organized in a table. One row of the table is dedicated to details of contact about a particular person. The items in the columns or fields are attributes or information/ data elements related to that person. Names (may be split as first and last names) and phone number would be the minimum amount of details. Work phone, home phone, mobile phone and any number of other details (birthday, and other anniversaries and so on) could be held in such a tabular arrangement.
Some examples of info in a database are:
Why do we need database management software then? Well it is apparent from the prior discussion, you may need to create different kinds of tables, modify its structure sometimes or remove the table entirely. With the relational model it is possible to have multiple tables in a database where another table may have related data. Any organization will need many types of data to be organized in unique databases. Database management software helps with creation of all kinds of database you need.
A DBMS or database management system is a collection of software that helps creation of these databases. The database management software system also implements a query language. The query language lets the user search for relevant data specified through the query language. With relational databases this query language is the SQL or structured query language and is supported by all the relational database management software systems (RDBMSs). Though supposedly standard, each manufacturer has a little twist to the language support through their DB management systems. Essential these are some proprietary extensions to the core functions of the operations defined in the SQL standard. When these data searching and manipulations are carried, one needs records of what operations and changes were done. Thus report generation is an important function of the database management software systems. Often the reporting functions are supported by graphical charting functions to help add meaning to the reported information easily. On-screen viewing and printing support are other functions provided. One important set of features help configure the database management software system and tweak parameters to fine-tune performance. Some examples of RDBMS are Oracle, SQL Server, DB2 and MySQL. A lot of housekeeping work including backup, restore and disaster recovery, etc. are often included in database management systems.
What is SQL or Structured Query Language becomes easier to understand if we look at database systems first. A database is a repository of data vital to the activities that need large amounts of data to be stored. Businesses are examples of such activities. Usually such data is used again and again. That requires the data to be organized and easily accessible. Retrieval or update of such data is required to be accurate. Relational databases allow users to set up flexible search criteria to accurately locate a specific data item. Relational databases organize data as tables of rows and columns. RDBMS lets users create flexible queries and locate data accurately. Query language offers standardized syntax to specify such queries. When found, operations possible on the data using Structured Query Language are:
RDBMS or the relational database management systems use SQL programming language. SQL is a standardized form of proprietary query languages used by the product companies. Structured Query Language is a standard of both ANSI and ISO organizations. Standardization makes migrating easier. Substantial changes to the SQL statements used in an application should not be required when moved to another database.
Many of the database products use SQL. Major, well-known database products available are Oracle, IBM DB2, Microsoft SQL Server, etc. Open source MySQL is a very popular product. Structured Query Language available with each of these products offer the core functions. Unfortunately, these companies implement additional functions. The core functions offer select, insert, create, update, delete and drop, etc. These are really sufficient to implement most operations one needs. SQL of these products coupled with the extensions are known differently. T-SQL is offered by Microsoft in SQL Server product while the Oracle version is called PL/SQL.
Distributed database applications, typically, work with a central database server known as the backend. Client applications communicate with this back-end to retrieve data and manipulate them. These clients issue queries for data with Structured Query Language statements. The database server is then updated with the changed data.
SQL is able to change/modify data in the RDBMS. Besides, it is able to change the structure of the database tables. Structured Query Language statements will let a user create a table, modify it or even entirely delete it. What SQL statements can do with data is insert data into fields in the table. What SQL lets you do is to “select” a specific table for modifications. A SQL “update” command changes the value of a piece (field) of data.
If you need to work with RDBMS applications, the core functions that constitute what is SQL would be easy to learn. There are only a few commands that are used. Learning the syntax of how the command word and associated parameters are used is quite simple too. Even when your application needs to migrate to any other RDBMS, it should not be difficult to manage. Optimization can be implemented through the core SQL first, the product specific extensions can be done as a next step.
ODBC is the abbreviation of “Open Database Connectivity”. It is a standard that specifies how an application using data from database will interact with a database. ODBC is a standard adopted by the IT industry. The standard specifies the commands that can be issued irrespective of the actual database product. How database products (both RDBMS and non relational ones) respond to requests for finding data, modifying or editing them as also how the requests are to be made vary from product to product. Open Database Connectivity strives to make the requests from applications the same irrespective of which database product serves the data. Databases, on their part, interpret these requests and process data according to their own internal processes (requests and command syntax) to respond the same way irrespective of its make.
With this kind of standardization, it is possible for any application to write front end that issues the standard requests to databases. This is the front end part of the ODBC standardization/ specification. This makes it possible for any application to issue data requests that will be recognized any ODBC compliant database. In fact, the application with this kind of Open Database Connectivity compliant front end would be transparent to what database is going to supply the data requested by it. The database could be any ODBC compliant product, working on any computer on the network and on any operating environment. Like the application front end needs special code to transform the requests from the application to standardized requests, the database needs a driver that will recognize the Open Database Connectivity requests and transform them to commands in specific syntax and sequence required by the given database. These drivers are, obviously, specific to a database product of a particular company. This driver is installed with the client application, the database could be anywhere on the network. The chain of modules for getting ODBC compliant work done is as follows:
Database serves up data requested and changed made by application up the same chain. After this ODBC standards have been complied with creating an application with a database, removing the parts and replacing them with another is a simple affair. As long as the standard connections through the front end and the Open Database Connectivity driver are maintained, substituting the database with another or an application with another is as simple as changing the tire in a car. It does not matter if the tire is from Bridgestone, Michelin or something else as long as the dimensions (specs of database) of the tire are similar. One could write monolithic application that has the database as a part of it. The application communicates with the database in its native protocol. This will be alright if there was no need for any change during the lifetime of the application. If there is a change needed, you will need to re-write the application all over again. The flexibility arising from ODBC standardization will be lost entirely.
SQL Server Management Studio or SSMS is a product that is a part of Microsoft’s SQL Server 2012 product and has been available from the time the SQL Server 2005 came out. This is a component that helps manage all the parts of the SQL Server. SQL Server Management Studio 2012 can do the following for all the software modules in the server:
SSMS is a crucial product and a critical piece in managing the database product; it is necessary to become familiar with the product first. Starting with the SQL Server Management Studio Express studio then seems to be a prudent approach. Getting the express version of the SQL Server, which includes the Management Studio could be downloaded from the Microsoft site. Installing the product should not create any problems. You should invest in a regular version after your team is comfortable with the SQL Server Management Studio 2012.
The SQL server Management Studio is like the control center for the product and helps you manage the features of the major modules of the product. MS has their products available in different configurations. The express version is usually a free product that helps users get familiar with the tool before plunging in into larger configurations that are priced. The SQL Management Studio 2012 product download module includes a complete tutorial. The first step for familiarization should be to study this guide. You are provided an access to the user community. This can help with any queries you may have regarding the product, its installation and configuration.
The SQL Management Studio provides the following features that will help manage the server:
The Microsoft SSMS 2012 provides an activity monitor. It is possible to schedule actions at different times and to have multiple tool open at the same time. The SQL Server Management Studio can monitor these activities. If you needed an uncluttered and reduced higher level view, it is possible to apply filters.
The SQL Management Studio has an object explorer that can provide access to all types of objects within the server environment. Access to the SQL server agent for administering them in a replicated environment, filtering of schema, name or date is available. The SSMS will let you filter parts of these objects too. Objects inside the database could be populated asynchronously. If necessary, the objects could be filtered with the metadata associated to the objects.
Scripting capabilities keep getting updated with the server version releases. This is supported with templates for quick development; script editing could be off-line, even when disconnected from the server and a source control tool for managing the script sources.
SQL Server Management Studio capabilities could be extended, given the way it is built. However, the Microsoft does not promise any support for extensions users may build. No official documents that may help in such developments are also published. This policy is so strict that when you seek customer support, you need to remove any such extensions if you have any installed.
Visual Studio 2008 is a development system by Microsoft. It is an integrated development environment or IDE. An IDE usually has features that help write code, manage the source code, create the object code, run it and help debug it. Visual Studio 2008 is an IDE that supports several software tools that help is each of these departments. While Visual Studio has many editions, it is from Visual Studio 2008 version that has integration with SQL Server editions, starting with the SQL 2005. There have been several versions after Visual Studio 2008 too. Because of this, connection mentioned, it made sense to study Microsoft Visual Studio 2008. Visual Studio makes available multiple tools for each of the developments, testing, deployment, integration and management of a software system for and given application. Not only, there is a comprehensive set of tool but development across devise type is also supported. Your target device could be the web, a PC, a server or some mobile device.
Visual Studio 2008 integrates tools, servers as well as services. It offers these features to make development and solving related problems relatively easy. So much so that not only experienced developers benefit from it but even beginners are able to get used to the tools and services quite easily. Productivity in development is helped by code editors that are quite efficient. Intellisense feature and wizards help developers manage their development functions. Intellisense is like auto-completion so that code statement’s completion is helped by the system automatically prompting the required parameters. That would avoid mistakes and make code development faster in Microsoft Visual Studio 2008 environment.
Life cycle management support through tools like Visual Studio Team System is available. MS Visual Studio Team system is a team collaboration product. This tool can help developers with work-item tracking and provide a team portal. By tracking the work items, it can manage version control too. Build management, business intelligence and process guidance are other features available through this component of Visual Studio 2008.
Visual Studio 2008 offers the team system that is a combination of products. These are:
Visual Studio 2008 is available in two major editions; the standard edition and the professional edition. Microsoft Visual Studio 2008 standard edition provides an integrated environment as described. It is a complete development environment for applications for the web or the Windows.
Visual Studio 2008 Professional edition provides additional features beyond the standard edition. Developing ASP.NET or .NET AJAX based supplications for the web or for the different Windows versions, this tool will let you work with SQL Server databases as also mobile devices. This Visual Studio 2008 Pro version also has unit testing built in to get software modules tested early on. This tool helps integrate Microsoft’s productivity suite easily too.