Showing posts with label SQL. Show all posts
Showing posts with label SQL. Show all posts

Clauses Of SQL Lesson 02

1.5.14 5 comments
01.Select

This is to specify  the columns needed  for  Output.

The column names that follow the select keyword determine which columns will be returned in the results. You can select as many column names that you'd like, or you can use a "*" to select all columns.

 example-(a) select Sname , Marks
            (b) select *

02.From

specifies the table that will be queried to retrieve the desired results.

 example-(a) from Student
            (b) From EMP

03.Where

Specifies the Conditional creative a that applies to data.

example-(a) where marks>=50
            (b) where SName='Jone'


Conditional selections used in the where clause:
=Equal
>Greater than
<Less than
>=Greater than or equal
<=Less than or equal
<>Not equal to
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What is SQL? Lesson 01

27.4.14 0 comments
SQL (pronounced "ess-que-el") stands for Structured Query Language. SQL is used to communicate with a database. According to ANSI (American National Standards Institute), it is the standard language for relational database management systems. SQL statements are used to perform tasks such as update data on a database, or retrieve data from a database. Some common relational database management systems that use SQL are: Oracle, Sybase, Microsoft SQL Server, Access, Ingres, etc. Although most database systems use SQL, most of them also have their own additional proprietary extensions that are usually only used on their system. However, the standard SQL commands such as "Select", "Insert", "Update", "Delete", "Create", and "Drop" can be used to accomplish almost everything that one needs to do with a database. This tutorial will provide you with the instruction on the basics of each of these commands as well as allow you to put them to practice using the SQL Interpreter.


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