What is What in SQL

What is Table?

• Tables: These are where data is kept within the database. A database must contain at leastone table to be of use, although you can have a database with no user tables and only systemtables. System tables are special tables that SQL Server uses to help it work with the database.These tables contain information within rows and columns, much like in Excel, but they havea great deal more power than cells within Excel. Temporary tables—another type of databasetable—can take several different forms.

What is Column?
• Columns: These provide a definition of each single item of information that builds up to atable definition. A column is made up of cells that all hold data, much like a column in Excel.Unlike in Excel, though, where each cell can hold a different type of data, a column within aSQL Server table is restricted to what the data within it relates to, the type of data it will hold,and how much information can be stored in it. Each table must have at least one column,although the column doesn’t need to contain any information.

What is Row?
• Rows: A row is made up of one cell from every column defined for the table. There can be anynumber of rows in a table; you are limited only by your disk space, the amount of disk spacethat you defined as the maximum in your database creation definition, or the amount of diskspace on your server. A row will define a single unit of information, such as a user’s bankaccount details or a product on an e-commerce site. Rows are also called records.

What is Stored Procedure?
• Stored procedures: When it comes to requiring a program to manipulate or work with data, orperform the same data-intensive task repeatedly, it’s often better to store this code in a storedprocedure. Stored procedures contain one or more T-SQL statements, which are compiledand ready to be executed when required. Stored procedures are permanently stored in thedatabase, ready for use at any time.

What is T-SQL Statement?
• T-SQL statements: A T-SQL statement is a program statement that SQL Server can use to workwith your data.

What are assemblies?
• Assemblies: These arrived with SQL Server 2005. Assemblies are similar to stored procedures,in that they can be used to manipulate or work with data, but they are used more for procedurallogic, as you might find in a .NET program. An assembly can be more than a replacement for astored procedure and can take on many different guises—for example, you can also builddata types using an assembly.

What is Index?
• Indexes: These can be regarded as predefined lists of information that can inform the databasehow the data is physically sorted and stored, or they can be used by SQL Server to findrows of data quickly using information supplied by a T-SQL query and matching this informationto data within columns. An index consists of one or more columns from the table it isdefined for, but it is not possible for an index to cover more than one table. An index in SQLServer is very much like the index of a book, which is used to locate a piece of informationfaster than looking through the book page by page.

What is view?
• Views: These can be thought of as virtual tables. Views can contain information combinedfrom several tables and can present a more user-friendly interface to the data. Views can alsoadd a great deal of security to an application, but they do give reduced functionality over theuse of stored procedures or direct access to the tables. Views can also be indexed to speedprocessing of data within.

What is function in sql server?
• Functions: A function is similar to a stored procedure, but it takes information one row at atime or produces information one row at a time as you work through the rows of data you areprocessing. For example, you would use a stored procedure to produce output to create astatement, but you would use a function to go through each transaction one at a time tocalculate interest on a daily basis.

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