Technology Questions

There are two kinds of classes in c++. They are absolute class and concrete class.

SELECT  * from Employees  WHERE  upper(EmpName) like upper('joe%');

There are two types of modular programming.They are interface and implementation.

we can always fetch from one database and rewrite to another. Here is a nice solution of it.$db1 = mysql_connect("host","user","pwd")
mysql_select_db("db1", $db1);
$res1 = mysql_query("query",$db1);$db2 = mysql_connect("host","user","pwd")
mysql_select_db("db2", $db2);
$res2 = mysql_query("query",$db2);At this point you can only fetch records from you previous ResultSet, i.e $res1 – But you cannot execute new query in $db1, even if you supply the link as because the link was overwritten by the new db.so at this point the following script will fail
$res3 = mysql_query("query",$db1); //this will failSo how to solve that?

take a look below.
$db1 = mysql_connect("host","user","pwd")
mysql_select_db("db1", $db1);
$res1 = mysql_query("query",$db1);

$db2 = mysql_connect("host","user","pwd", true)
mysql_select_db("db2", $db2);
$res2 = mysql_query("query",$db2);

So mysql_connect has another optional boolean parameter which indicates whether a link will be created or not, as we connect to the
$db2 with this optional parameter set to 'true', so both link will remain live.

Now the following query will execute successfully.
$res3 = mysql_query("query",$db1);

DAO (Data access object ) is used for accessing data before ado it was used for database installed on same sys where the application resides.

RDO (Remote data object ) is used for accessing remote data

ADO (Active data object ) most powerful till date it is nothing but combination of both DAO and RDO 

PHP developed for less script, time saving, Free Open Source Software and runs on different platforms such as Windows, Linux, Unix, etc. PHP compatible with almost all servers used today such as Apache, IIS, etc.

The PHP scripting language resembles JavaScript, Java, and Perl, These languages all share a common ancestor, the C programming language. PHP has full access to the information that the server has, and very little access to information that the client has. In fact, it only has information that the client tells the server and that the server passes on to PHP. Because it is on the server, however, PHP cannot be modified by the client. While you cannot necessarily trust the information that the client gives to PHP, you can trust that your PHP is doing what you told it to do. Because PHP is on the server end, your PHP scripts can affect your server -- such as by keeping an activity log or updating a database.