Technology Questions

SQL has IsDate() function which is used to check passed value is date or not of specified format ,it returns 1(true) or 0(false) accordingly.

SELECT  ISDATE('1/08/13') AS "MM/DD/YY";

It will return 0 because passed date is not in correct format.

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);

When amount of memory to be allocated is known beforehand i.e. at the the time of compilation, it is known as Static Memory Allocation. Once the memory is allocated statically, it cannot be deallocated during program run. So it leads to wastage of storage space.

Example:

int A[100];

When amount of memory to be allocated is not known beforehand, rather it is determined at the time of program run, it is called Dynamic Memory Allocation. It leads to efficient utilization of storage space.

Example:

cout << " Enter number of elements: ";

cin >> N;

int *A = new int[N]; // dynamic memory allocation

The comparison operator that is used in SQL is '='. Comparison operators test whether two expressions are the same. Comparison operators can be used on all expressions except expressions of the text, ntext, or image data types.

Open addressing (closed hashing),

The methods used include: Overflow block,

 Closed addressing (open hashing)

The methods used include: Linked list, Binary tree…

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.