Friday, 30 November 2012

Aggregate Functions:

They are used to compute a single value from a set of attribute values of a column:

count :

how many rows(tuples) are stored in the relation EMP

select count(*) from EMP;

how many different job title are stored in the relation EMP

select count(distinct job) from EMP;

max & min:

select min(SAL),max(SAL) from EMP

select max(SAL)- min(SAL) from EMP

sum:

select sum(SAL) from EMP

avg:

String operations in Database:

In order to compare an attribute with string,it is required to surround the string by apostrophes ,e.g where LOCATION=’DALLAS’.A powerful operator for pattern matching is the like operator . Together with this operator ,two special characters are used ;the percent sign % (also called wild card),and the underline _,also called position marker e.gif one is interested in all tuples of the table DEPT that contain two C in the name of the department ,the condition would be where DNAME like “%C%C%”.the % sign means that any (sub)string is allowed there ,even the empty string .in contrast ,the underline stands for exactly one character .Thus the condition where DNAMElike “%C_C%” would require that exactly one character appears between the two Cs .To test for inequality ,the not clause is used.

Further string operation are :

1.upper

2.lower

3.initcap

4.length

5.substr

PL/SQL

Structure of PL/SQL:

Declare

Begin

exception

End

Know in PL/SQL:

About

1.Exception handling

2.Procedures

3.Functions

4.assertions

5.Triggers

Friday, 23 November 2012

<abbr> Tag

The <abbr> tag is supported in all major browsers.

Note: The <abbr> tag is not supported in IE 6 or earlier versions.

Tip: The global title attribute can be used in the <abbr> tag to show the full version of the abbreviation/acronym when you mouse over the <abbr> element.

<acronym> Tag

<bdo> Tag

<bdo dir="rtl">
This text will go right-to-left.
</bdo>

The <caption> tag defines a table caption.

<del> Tag

<p>My favorite color is <del>blue</del> <ins>red</ins>!</p>

<fieldset> Tag

<!DOCTYPE html>

<html>

<body>

<form>

<fieldset>

<legend>Personalia:</legend>

Name: <input type="text"><br>

Email: <input type="text"><br>

Date of birth: <input type="text">

</fieldset>

</form>

</body>

</html>

<hr> Tag

<!DOCTYPE html>

<html>

<body>

<h1>HTML</h1>

<p>HTML is a language for describing web pages.</p>

<hr>

<h1>CSS</h1>

<p>CSS defines how to display HTML elements.</p>

</body>

</html>

<mark> Tag

<!DOCTYPE html>

<html>

<body>

<p>Do not forget to buy <mark>milk</mark> today.</p>

</body>

</html>

<meter> Tag

<!DOCTYPE html>

<html>

<body>

<p>Display a gauge:</p>

<meter value="2" min="0" max="10">2 out of 10</meter><br>

<meter value="0.6">60%</meter>

<p><b>Note:</b> The <meter> tag is not supported in IE and Safari.</p>

</body>

</html>

<nav> Tag

<!DOCTYPE html>

<html>

<body>

<nav>

<a href="/html/">HTML</a> |

<a href="/css/">CSS</a> |

<a href="/js/">JavaScript</a> |

<a href="/jquery/">jQuery</a>

</nav>

</body>

</html>

<optgroup> Tag

<!DOCTYPE html>

<html>

<body>

<select>

<optgroup label="Swedish Cars">

<option value="volvo">Volvo</option>

<option value="saab">Saab</option>

</optgroup>

<optgroup label="German Cars">

<option value="mercedes">Mercedes</option>

<option value="audi">Audi</option>

</optgroup>

</select>

</body>

</html>

<param> Tag

<!DOCTYPE html>

<html>

<body>

<p><b>Note:</b> IE does not support .wav files. Try to rename the file to "horse.mp3" to test the example in IE.</p>

<object data="horse.wav">

<param name="autoplay" value="true">

</object>

</body>

</html>

<pre> Tag

<!DOCTYPE html>

<html>

<body>

<p><b>Note:</b> IE does not support .wav files. Try to rename the file to "horse.mp3" to test the example in IE.</p>

<object data="horse.wav">

<param name="autoplay" value="true">

</object>

</body>

</html>

<progress> Tag

<!DOCTYPE html>

<html>

<body>

Downloading progress:

<progress value="50" max="100">

</progress>

<p><b>Note:</b> The <progress> tag is not supported in IE and Safari.</p>

</body>

</html>

<s> Tag

<!DOCTYPE html>

<html>

<body>

<p><s>My car is blue.</s></p>

<p>My new car is silver.</p>

</body>

</html>

<strike>

<!DOCTYPE html>

<html>

<body>

<p>Version 2.0 is <strike>not yet available!</strike> now available!</p>

</body>

</html>

<sub> and <sup>Tags

<!DOCTYPE html>

<html>

<body>

<p>This text contains <sub>subscript</sub> text.</p>

<p>This text contains <sup>superscript</sup> text.</p>

</body>

</html>

Friday, 30 November 2012

Aggregate Functions:

String operations in Database:

PL/SQL

Friday, 23 November 2012

Tags

<abbr> Tag

<bdo> Tag

<caption> Tag

<col> Tag

<del> Tag

<fieldset> Tag

<hr> Tag

<mark> Tag

<meter> Tag

<nav> Tag

<optgroup> Tag

<param> Tag

<pre> Tag

<progress> Tag

<s> Tag

<strike>

<sub> and <sup>Tags

Monday, 5 November 2012

Codes