October 11, 2018

Sreekanth B

NetApp Most Frequently Asked PHP Latest Interview Questions Answers

What Is Session_register()?

session_register() is old function that registers global variables into the current session. You should stop using session_register() and use array $_SESSION to save values into the current session now.

What Do You Need To Connect Php To Mysql?

If you want to access MySQL database server in your PHP script, you need to make sure that MySQL module is installed and turned on in your PHP engine. Check the PHP configuration file, php.ini, to make sure the extension=php_mysql.dll is not commented out.
The MySQL module offers a number of functions to allow you to work with MySQL server. Some commonly used MySQL functions are:
• mysql_connect -- Open a connection to a MySQL Server
• mysql_close -- Close MySQL connection
• mysql_db_query -- Send a MySQL query
• mysql_fetch_array -- Fetch a result row as an associative array, a numeric array, or both
• mysql_free_result -- Free result memory
• mysql_list_tables -- List tables in a MySQL database
• mysql_list_fields -- List MySQL table fields

NetApp Most Frequently Asked PHP Latest Interview Questions Answers
NetApp Most Frequently Asked PHP Latest Interview Questions Answers

How To Connect To Mysql From A Php Script?

If you want access the MySQL server, you must create a connection object first by calling the mysql_connect() function in the following format:
$con = mysql_connect($server, $username, $password);
If you are connecting to a local MySQL server, you don't need to specify username and password. If you are connecting to a MySQL server offered by your Web hosting company, they will provide you the server name, username, and password.
The following script shows you how to connect to a local MySQL server, obtained server information, and closed the connection:
<?php
$con = mysql_connect('localhost');
print(mysql_get_server_info($con)."\n");
print(mysql_get_host_info($con)."\n");
mysql_close($con);
?>

How To Run A Sql Statement?

You can run any types of SQL statements through the mysql_query() function. It takes the SQL statement as a string and returns different types of data depending on the SQL statement type and execution status:

• Returning FALSE, if the execution failed.
• Returning a result set object, if the execution is successful on a SELECT statement or other statement returning multiple rows of data.
• Returning TRUE, if the execution is successful on other statements.

Here is a good example of running a SQL statement with the mysql_query() function:

<?php
include "mysql_connection.php";
$sql = 'SELECT sysdate() FROM dual';
$rs = mysql_query($sql, $con);
$row = mysql_fetch_array($rs);
print("Database current time: ". $row[0] ."\n");
mysql_close($con);
?>

How To Get The Number Of Rows Selected Or Affected By A Sql Statement?

There are two functions you can use the get the number of rows selected or affected by a SQL statement:

mysql_num_rows($rs) - Returns the number of rows selected in a result set object returned from SELECT statement.
mysql_affected_rows() - Returns the number of rows affected by the last INSERT, UPDATE or DELETE statement.

What Is A Result Set Object?

A result set object is a logical representation of data rows returned by mysql_query() function on SELECT statements. Every result set object has an internal pointer used to identify the current row in the result set. Once you get a result set object, you can use the following functions to retrieve detail information:
• mysql_free_result($rs) - Closes this result set object.
• mysql_num_rows($rs) - Returns the number rows in the result set.
• mysql_num_fields($rs) - Returns the number fields in the result set.
• mysql_fetch_row($rs) - Returns an array contains the current row indexed by field position numbers.
• mysql_fetch_assoc($rs) - Returns an array contains the current row indexed by field names.
• mysql_fetch_array($rs) - Returns an array contains the current row with double indexes: field position numbers and filed names.
• mysql_fetch_lengths($rs) - Returns an array contains lengths of all fields in the last row returned.
• mysql_field_name($rs, $i) - Returns the name of the field of the specified index.

What Is File Upload?

File upload is Web page function which allows visitor to specify a file on the browser's system and submit it to the Web server. This is a very useful function for many interactive Web sites. Some examples are:

Web base email systems for users to send attachments.
 Forums that allows user to submit pictures.
 Web sites file managers for users to build their own Web pages.
Which HTML Tag Allows Users to Specify a File for Uploading?
To present an input field on your Web page to allow users to specify a local file to upload, you need to use the <INPUT TYPE="FILE" ...> tag inside a <FORM ...> tag. The <INPUT TYPE="FILE" ...> will be displayed as a text input field followed by a button called "Browse...". Users can either enter the full path name of a local file, or click Browse button to go through a dialog box to select a file interactively. The following PHP code shows you a good example of the file upload tag:

<?php
print("<html><form>n");
print("<input type=file>n");
print("<input type=submit>n");
print("</form></html>n");
?>

What Is The Difference Between Char And Varchar Data Types?
CHAR is a fixed length data type. CHAR(n) will take n characters of storage even if you enter less than n characters to that column. For example, "Hello!" will be stored as "Hello! " in CHAR(10) column.

VARCHAR is a variable length data type. VARCHAR(n) will take only the required storage for the actual number of characters entered to that column. For example, "Hello!" will be stored as "Hello!" in VARCHAR(10) column.

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