Category Archives: php

Upload in Firefox 3

Recently i tried to use a swfupload pluggin, using php. I couldnt meke it work in Firefox 3. But in all other browsers worked like a charm. I couldnt stand the idea that this was the only time that firefox was the sticky browser. So I decided to test it in another computer with firefox 3.0.2 also installed. In my laptop all browsers were working ok, including firefox3. So what was the problem ?????

Once more, nod32 + wampserver. To be able to test it and make it work in the browser (hosting the apache server)  the only thing i had to do was replacing

//localhost:8080/
with
//[my computer IP]:8080/

+ = real pain in the @ss!

Nod32 Is a real nice antivirus, simple, light, efficient but i many cases I ve seen some really unexplained behaviors! See also Nod32 WampServer Fix

Keep that in mind!!

MySQL Command List


This is a list of the most common used mySQL Commands

General Commands

USE database_name
Change to this database. You need to change to some database when you first connect to MySQL.
SHOW DATABASES
Lists all MySQL databases on the system.
SHOW TABLES [FROM database_name]
Lists all tables from the current database or from the database given in the command.
DESCRIBE table_name
SHOW FIELDS FROM table_name
SHOW COLUMNS FROM table_name
These commands all give a list of all columns (fields) from the given table, along with column type and other info.
SHOW INDEX FROM table_name
Lists all indexes from this tables.
SET PASSWORD=PASSWORD(‘new_password’)
Allows the user to set his/her own password.
Table Commands
CREATE TABLE table_name (create_clause1, create_clause2, …)
Creates a table with columns as indicated in the create clauses.
create_clause
column name followed by column type, followed optionally by modifiers. For example, “gene_id INT AUTO_INCREMENT PRIMARY KEY” (without the quotes) creates a column of type integer with the modifiers described below.
create_clause modifiers
  • AUTO_INCREMENT : each data record is assigned the next sequential number when it is given a NULL value.
  • PRIMARY KEY : Items in this column have unique names, and the table is indexed automatically based on this column. One column must be the PRIMARY KEY, and only one column may be the PRIMARY KEY. This column should also be NOT NULL.
  • NOT NULL : No NULL values are allowed in this column: a NULL generates an error message as the data is inserted into the table.
  • DEFAULT value : If a NULL value is used in the data for this column, the default value is entered instead.
DROP TABLE table_name
Removes the table from the database. Permanently! So be careful with this command!
ALTER TABLE table_name ADD (create_clause1, create_clause2, …)
Adds the listed columns to the table.
ALTER TABLE table_name DROP column_name
Drops the listed columns from the table.
ALTER TABLE table_name MODIFY create_clause
Changes the type or modifiers to a column. Using MODIFY means that the column keeps the same name even though its type is altered. MySQL attempts to convert the data to match the new type: this can cause problems.
ALTER TABLE table_name CHANGE column_name create_clause
Changes the name and type or modifiers of a column. Using CHANGE (instead of MODIFY) implies that the column is getting a new name.
ALTER TABLE table_name ADD INDEX [index_name] (column_name1, column_name2, …)
CREATE INDEX index_name ON table_name (column_name1, column_name2, …)
Adds an index to this table, based on the listed columns. Note that the order of the columns is important, because additional indexes are created from all subsets of the listed columns reading from left to write. The index name is optional if you use ALTER TABLE, but it is necesary if you use CREATE INDEX. Rarely is the name of an index useful (in my experience).
Data Commands
INSERT [INTO] table_name VALUES (value1, value2, …)
Insert a complete row of data, giving a value (or NULL) for every column in the proper order.
INSERT [INTO] table_name (column_name1, column_name2, …) VALUES (value1, value2, …)
INSERT [INTO] table_name SET column_name1=value1, column_name2=value2, …
Insert data into the listed columns only. Alternate forms, with the SET form showing column assignments more explicitly.
INSERT [INTO] table_name (column_name1, column_name2, …) SELECT list_of_fields_from_another_table FROM other_table_name WHERE where_clause
Inserts the data resulting from a SELECT statement into the listed columns. Be sure the number of items taken from the old table match the number of columns they are put into!
DELETE FROM table_name WHERE where_clause
Delete rows that meet the conditions of the where_clause. If the WHERE statement is omitted, the table is emptied, although its structure remains intact.
UPDATE table_name SET column_name1=value1, column_name2=value2, … [WHERE where_clause]
Alters the data within a column based on the conditions in the where_clause.
LOAD DATA LOCAL INFILE ‘path to external file’ INTO TABLE table_name
Loads data from the listed file into the table. The default assumption is that fields in the file are separated by tabs, and each data record is separated from the others by a newline. It also assumes that nothing is quoted: quote marks are considered to be part of the data. Also, it assumes that the number of data fields matches the number of table columns. Columns that are AUTO_INCREMENT should have NULL as their value in the file.
LOAD DATA LOCAL INFILE ‘path to external file’ [FIELDS TERMINATED BY ‘termination_character’] [FIELDS ENCLOSED BY ‘quoting character’] [LINES TERMINATED BY ‘line termination character’] FROM table_name
Loads data from the listed file into the table, using the field termination character listed (default is tab \t), and/or the listed quoting character (default is nothing), and/or the listed line termination chacracter (default is a newline \n).
SELECT column_name1, column_name2, … INTO OUTFILE ‘path to external file’ [FIELDS TERMINATED BY ‘termination_character’] [FIELDS ENCLOSED BY ‘quoting character’] [LINES TERMINATED BY ‘line termination character’] FROM table_name [WHERE where_clause]
Allows you to move data from a table into an external file. The field and line termination clauses are the same as for LOAD above. Several tricky features:

  1. Note the positions of the table_name and where_clause, after the external file is given.
  2. You must use a complete path, not just a file name. Otherwise MySQL attempts to write to the directory where the database is stored, where you don’t have permission to write.
  3. The user who is writing the file is ‘mysql’, not you! This means that user ‘mysql’ needs permission to write to the directory you specify. The best way to do that is to creat a new directory under your home directory, then change the directory’s permission to 777, then write to it. For example: mkdir mysql_output, chmod 777 mysql_output.

Privilege Commands
Most of the commands below require MySQL root access
GRANT USAGE ON *.* TO user_name@localhost [IDENTIFIED BY ‘password’]
Creates a new user on MySQL, with no rights to do anything. The IDENTIFED BY clause creates or changes the MySQL password, which is not necessarily the same as the user’s system password. The @localhost after the user name allows usage on the local system, which is usually what we do; leaving this off allows the user to access the database from another system. User name NOT in quotes.
GRANT SELECT ON *.* TO user_name@localhost
In general, unless data is supposed to be kept private, all users should be able to view it. A debatable point, and most databases will only grant SELECT privileges on particular databases. There is no way to grant privileges on all databses EXCEPT specifically enumerated ones.
GRANT ALL ON database_name.* TO user_name@localhost
Grants permissions on all tables for a specific database (database_name.*) to a user. Permissions are for: ALTER, CREATE, DELETE, DROP, INDEX, INSERT, SELECT, UPDATE.
FLUSH PRIVILEGES
Needed to get updated privileges to work immediately. You need RELOAD privileges to get this to work.
SET PASSWORD=PASSWORD(‘new_password’)
Allows the user to set his/her own password.
REVOKE ALL ON [database_name.]* FROM user_name@localhost
Revokes all permissions for the user, but leaves the user in the MySQL database. This can be done for all databases using “ON *”, or for all tables within a specific databse, using “ON database_name.*”.
DELETE FROM mysql.user WHERE user=’user_name@localhost’
Removes the user from the database, which revokes all privileges. Note that the user name is in quotes here.
UPDATE mysql.user SET password=PASSWORD(‘my_password’) WHERE user=’user_name’
Sets the user’s password. The PASSWORD function encrypts it; otherwise it will be in plain text.
SELECT user, host, password, select_priv, insert_priv, shutdown_priv, grant_priv FROM mysql.user
A good view of all users and their approximate privileges. If there is a password, it will by an encrytped string; if not, this field is blank. Select is a very general privlege; insert allows table manipulation within a database; shutdown allows major system changes, and should only be usable by root; the ability to grant permissions is separate from the others.
SELECT user, host, db, select_priv, insert_priv, grant_priv FROM mysql.db
View permissions for individual databases.

Header("Location") on PHP

So check out this code…..

if(1== 1) { header("Location: index.php"); }
header("Location: http://www.google.com");

This simple code will be expected to redirect to index.php since 1==1 is always true. And for a weird reason it returns to redirect to www.google.com.

Maybe for a reason i didn’t quite understand this, but it should be written like this

if(1== 1) {
	header("Location: index.php");
}
else {
	header("Location: http://www.google.com");
}

As mentioned before the only logical explanation is that this command is a client side command that means the script doesn’t stop from being executed till end. My guess is that header location, first of all has to be executed before anything has sent to html output, so it does fill the html with this line
.

Retain scroll position after browser refresh

Retain scroll position after browser refresh
As Joel Spolsky points out, updating web pages by getting just the bits of information that have changed instead of refreshing the whole page is the wave of the future. Whether we’re calling web services within a client-side page or using a gmail-like JavaScript technique (darn cool), it’s going to be a major architectural shift. It’s going to be hard.

In the meantime, there is a really easy way to fix the problem of having to scroll back down to the part of the page you were using when a refresh occurred. Because ASP.NET’s post-back model forces a trip to the server for anything interesting to happen, this technique is essential if you’re using ASP.NET. However, it works just as well in Perl, PHP, JSP – whatever your server-side technology. It requires client-side JavaScript to be enabled, but so do the fancier techniques we are looking forward to.
Note that you could also just turn “smart navigation” on in ASP.NET, but I’ve had issues where smart navigation messes up other JavaScript. I prefer not to use it.
I’ve implemented an example of the technique for this post separately in PHP and ASP.NET/C#. You can see the PHP example in action or download a zip file of the ASP.NET/C# example. For both examples, I use hidden fields and client-side script. They imply an http POST, and typically you will be posting to the same page. You could make it work with GET and/or with another page, but the problem itself gets more confusing in those scenarios.

Here is the complete PHP example:

Continue reading Retain scroll position after browser refresh

Vars from PHP to JS and Back

The easy part is to add a js variable from php.
<html>
<?php
$MyVar3 = “Something in PHP”;
?>
<script language=”JavaScript”>
alert(<?php print “‘”.$MyVar3.”‘”; ?>);
</script>
</html>

The hard part is to take values from Javascript to PHP

<html>
<script language=”JavaScript”>
var JSVar = ‘something from JS code’;
</script>
<?php

$MyVar1 = “?><script language=javascript>document.write(‘Something you want’);</script><?php”;
$MyVar1 = str_replace(“?>”, “”, $MyVar1);
print $MyVar1.”<br><br>”;

$MyVar2 = “?><script language=javascript>document.write(JSVar);</script><?php”;
$MyVar2 = str_replace(“?>”, “”, $MyVar2);
print $MyVar2;
?>
</html>

Maximize the maximum values in php scripts

In some cases you need to make a custom script for uploading files or even update / synchronize two databases.  The php execution time has some restrictions, for security reasons. If a scripts takes more than apache server expects to take the whole procedure stops and your update script does not complete what its meant to do. In those cases you can actually do some changes like this

Find the php.in (in case you run a script in your local server). In a case you have to change tha php.ini in a hosted site, some hosters do give you this option.

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Resource Limits ;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;
max_execution_time = 240     ; Maximum execution time of each script, in seconds
max_input_time = 240    ; Maximum amount of time each script may spend parsing request data
memory_limit = 20M      ; Maximum amount of memory a script may consume (8MB)

if you post many data change this line (as you need to)

; Maximum size of POST data that PHP will accept.
post_max_size = 30M

If you need to upload file more than tha default (2M – 10M)

; Maximum allowed size for uploaded files.
upload_max_filesize = 25M

Firefox slow on localhost on Vista

Doing web development on my local machine – a Vista box – I was wondering why page rendering was so slow. First I thought my web application was not well done. But then I figured out that the pages rendered lightning fast on IE 7. And again later, I experienced, that the web application rendered pretty fast even in Firefox, when published to the live server.

Doing some research I found this blog entry, which was quite helpful.

The change of the Firefox setting network.dns.disableIPv6 to true did the trick. See screenshot below:

original Source: http://codepoetry.wordpress.com/

jQuery a great tool for any ServerSide Scripting Language

logo

One of the most used framework for making your web application more live, interactive. There is been a while since I run into it, but recently I decided to use it. Main reason is when i saw the sits that actually use the jQuery framework. Take a look here and you ll be suprised by the big company names.

Continue reading jQuery a great tool for any ServerSide Scripting Language