I'm trying to learn php and ran into a problem. I'd appreciate any help.
I have a database that looks like:
ID USER AGE
1 name1 18
2 name2 19
3 name3 20
etc etc
I want to delete multiple records. This is the code I am using for that:
<?php
$username = "root";
$password = "";
$hostname = "localhost";
//connection to the database
$dbhandle = mysql_connect($hostname, $username, $password)
or die("Unable to connect to MySQL");
echo "Connected to MySQL<br>";
//select a database to work with
$selected = mysql_select_db("photo",$dbhandle)
or die("Could not select examples");
//execute
echo "CONNECTED";
echo "</br>";
//Action
$delete_query = ("DELETE FROM _users WHERE age in(17,18,19)");
$result = mysql_query($delete_query);
echo 'Deleted';
mysql_close($dbhandle);
?>
When I am deleting by querying the age column, it deletes multiple rows okay.
However, when I do this:
$delete_query = ("DELETE FROM _users WHERE USER in(name1,name2,name3)");
Nothing happens. Is it because those are strings? How can I fix it?
Thanks!
The query is incorrect:
DELETE FROM _users WHERE USER in ('name1','name2','name3');
strings must be quoted, otherwise MySQL will see them as field names (or keywords). You have no error handling in your script, or you'd have seen the error messages. Always write a query as follows:
$result = mysql_query(...) or die(mysql_error());
this'll show you exactly WHY the query failed (or just continue on if there's nothing wrong).
DELETE FROM _users WHERE USER in(name1,name2,name3)
MySQL thinks that name1, name2, and name3 are columns. Quote them.
use single quote '
$delete_query = ("DELETE FROM _users WHERE `USER` in('name1','name2','name3')");
You need to encase the strings in quotes: WHERE USER in('name1', 'name2', 'name3')
Users is a string, you need to quote the values:
$delete_query = ("DELETE FROM _users WHERE USER in('name1','name2','name3')");
Yes, it's because they are strings. Strings need to be quoted properly, otherwise MySQL won't see them as strings. Use
$delete_query = ("DELETE FROM _users WHERE USER in('name1','name2','name3')");
Related
I have PHP script that runs every 3 hours that gets the amazon mws orders and save it into my database.
But before I insert an order into my table, I check first if the order exist
SELECT COUNT(*) total FROM orders WHERE transaction_id = "XXXXXXXXX"
But sometimes even if an order exist, the query will return 0. If return 0, I will insert the order into my table and it will end up duplicating the data.
This instance happens to me in my other PHP scripts and I don't understand the issue.
You should use something called as EXISTS for checking whether a row exists or not in your case order.
SELECT EXISTS(SELECT * FROM table1 WHERE ...);
SELECT EXISTS(SELECT * FROM tableName WHERE condition);
If your database uses master-slave mode，you can try to force the master to query.
You can also use the “INSERT IGNORE INTO orders ....” to ignore duplicate.
You may have an error in your MySQL query. I created a test table and write some code to print the result of the query which is working correctly.
You may not be using the quotations properly as this is the error most
of the time when you are working with queries in PHP
Here is the code
<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "practise";
// Create connection
$conn = mysqli_connect($servername, $username, $password, $dbname);
// Check connection
if (!$conn) {
die("Connection failed: " . mysqli_connect_errno());
}
$sql = "SELECT count(*) from test where title='Hello'";
$result = mysqli_query($conn,$sql);
$new =mysqli_fetch_array($result);
echo $new[0];
?>
</body>
</html>
And:
Image of the table where I am executing the query
The output against the MySQL query is:
2
The code works perfectly. If you have any other question, please share your code and I'll be more than happy to help you.
I am trying to update for some products their category in database. I want to find products that have in their name a specific word and after that I want to update the category for this products.
I want to select IDs from sho_posts where sho_posts.post_title contain this part of word '%Audio CD%' and after that to update the sho_term_relationships.term_taxonomy_id with value 2 where sho_term_relationships.object_id=sho_posts.id.
I wrote a little PHP code but it make only selection part. What is wrong?
<?php
$username = "user_name";
$password = "password";
$hostname = "host";
//connection to the database
$dbhandle = mysql_connect($hostname, $username, $password)
or die("Unable to connect to MySQL");
$selected = mysql_select_db("1812233_shoping",$dbhandle)
or die("Could not select examples");
echo "Connected to MySQL<br>";
$result = mysql_query ("SELECT `id` FROM `sho_posts` WHERE CONVERT(`post_title` USING utf8) LIKE '%Audio CD%' ");
while ($row = mysql_fetch_array($result)) {
echo "ID:".$row{'id'}."<br>";
}
$sql = "UPDATE 'sho_term_relationships'
SET 'term_taxonomy_id' = '123'
WHERE 'object_id' = $row";
//close the connection
mysql_close($dbhandle);
My new cod for script now is:
$username = "_shoping";
$password = "password";
$hostname = "localhost";
//connection to the database
$dbhandle = mysql_connect($hostname, $username, $password)
or die("Unable to connect to MySQL");
$selected = mysql_select_db("_shoping",$dbhandle)
or die("Could not select examples");
echo "Connected to MySQL<br>";
$result = mysql_query ("SELECT `id` FROM `sho_posts` WHERE CONVERT(`post_title` USING utf8) LIKE '%Audio CD%' ");
while ($row = mysql_fetch_array($result)) {
$id[] = $row['id'];
/*echo "ID2:".$id."<br>";*/
}
foreach ($id as $value) {
echo "value:".$value."<br>";
}
/*$id = $row['id'];*/
$sql = "UPDATE sho_term_relationships
SET term_taxonomy_id = '123'
WHERE object_id =".$value;
mysql_query($sql);
//close the connection
mysql_close($dbhandle);
now it make an update but only for one row, how to make for all rows? From select query I get 4 result
Try this:
$sql = "UPDATE sho_term_relationships
SET term_taxonomy_id = '123'
WHERE object_id = ".$row{'id'};
And make sure to run the query mysql_query($sql)
Also, I think you might want to add this query inside the while loop
You are using single quotes instead of backticks (which are in this case not necessary). Change your update query to this:
$sql = "UPDATE sho_term_relationships
SET term_taxonomy_id = 123
WHERE object_id = $row";
Also, you are missing some pieces of your code; nothing will be called on that query. It's not being executed at all.
Also you have some other problems here, mainly due to the high risk of sql injection. First of all stop using mysql_ functions, they are deprecated. You should prepare your variables. Here's a demonstration of the key parts of your script in mysqli_ format.
This should also solve most of your issues (there may be a few more if I don't full understand your original question).
You would call your database like this (and check for errors)
$dbhandle = new mysqli($hostname, $username, $password);
if ($dhandle->connect_error) {
die("Connection failed: " . $dbhandle->connect_error);
}
Then you would select your data like this (assuming that term might not be the same every time, and might be coming from a post variable named search).
Edit: For example, if you have an HTML form that is getting this variable like so:
<input type="select" name="search_term" />
you name the variable like this:
$search = $_POST['search_term'];
and then you set it up for your query for the like operator
$search_term = '%'.$search.'%';
$result = $dbhandle->prepare("SELECT `id`
FROM `sho_posts`
WHERE CONVERT(`post_title` USING utf8)
LIKE ? ");
$result->bind_param("s",$search_term);
$result->execute();
$result->bind_result($id);
And then you can get your data through the while loop like so
while ($result->fetch()) {
... stuff you want to do here...
}
$result->close();
Then you would use this in your update query (which would take a similar syntax), and you can just get the information from $id which was created with the bind_result above:
$sql = $dbhandle->("UPDATE sho_term_relationships
SET term_taxonomy_id = 123
WHERE object_id = ?");
$sql->bind_param("s",$id);
$sql->execute();
$sql->close();
It may take a little bit to get used to this, but I find it easier to parse, and also is much more secure
When i recently wanted to list all tables in a database in php i made the simple MySQL query:
$tables_query = mysql_query('show tables');
while ($test = mysql_fetch_array($tables_query)) {
echo "Table: {$test[0]}<br />";
}
The first result is
TABLES 105
address_book
I don't have a table called "TABLES 105" but the mysql_num_rows also shows, that there is 105 results, even that my database only contains 104 table
If i try to request "show tables" directly on the MySql server, it works fine and i get 104 rows as result. It also worked before and i can't seem to find anything about this, so im hoping someone can help me in here.
It also affect when i call directly to the mysql server. I got access with an other user login for an other database, on the same server and here is no issues at all.
Its questionable how that 105 got there in the first place, most likely this is caused by that mysql_num_rows function that you mentioned as fetch_array actually fetches the rows, but here's one on MySQLi, stop using MySQL anymore:
$db = 'test'; // database name
$con = mysqli_connect('localhost', 'username', 'password', $db);
$tables_query = mysqli_query($con, "SHOW TABLES FROM {$db}");
while($table = mysqli_fetch_assoc($tables_query)) {
echo $table["Tables_in_{$db}"], '<br/>';
}
An alternative way of course is to delve into information_schema:
$db = 'test'; // database name
$con = mysqli_connect('localhost', 'root', '', $db);
$tables_query = mysqli_query($con, "SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = '{$db}'");
while($table = mysqli_fetch_array($tables_query)) {
echo $table['TABLE_NAME'], '<br/>';
}
I have two databases, one online (mysql) and one in my office (SQL Server) which I would like to compare and update where a value is different.
I am using php to connect to the SQL Server database and run a query to retrieve the information, then connecting to the Mysql database running a query. Then I need to compare the two queries and update where necessary.
Is there somewhere I can look for tips on how to do this, I am sketchy on PHP and struggling really.
This is as far as I have got-:
<?php
$Server = "**server**";
$User = "**user**";
$Pass = "**password**";
$DB = "**DB**";
//connection to the database
$dbhandle = mssql_connect($Server, $User, $Pass)
or die("Couldn't connect to SQL Server on $Server");
//select a database to work with
$selected = mssql_select_db($DB, $dbhandle)
or die("Couldn't open database $DB");
//declare the SQL statement that will query the database
$query = "SELECT p.id, p.code, ps.onhand";
$query .= "FROM products p with(nolock)";
$query .= "INNER JOIN productstockonhanditems ps with(nolock)";
$query .= "ON ps.ProductID = p.ID";
$query .= "WHERE ps.StockLocationID = 1";
//execute the SQL query and return records
$get_offlineproduct2 = mssql_query($query);
mysql_connect("**Host**", "**username**", "**password**") or die(mysql_error());
mysql_select_db("Database_Name") or die(mysql_error());
$get_onlineproducts = mysql_query(SELECT w.ob_sku, w.quantity
FROM product_option_value AS w
ORDER BY ob_sku)
or die(mysql_error());
//close the connection
mssql_close($dbhandle);
?>
I am looking to compare the value p.code to w.ob_sku and whenever they match copy the value of ps.onhand to w.quantity so the online database has the correct quantities from the office database.
My question I guess is how close am I to getting this right? Also am I doing this the right way, I don't want to get so far and realise that i am just wasting my time...
Thanks!
You do not need to fetch any record from MySQL, since you actually want to update it.
I would do something like this:
$query = 'SELECT p.code, ps.onhand FROM (...)';
// execute the SQL query and return a result set
// mssql_query() actually returns a resource
// that you must iterate with (e.g.) mssql_fetch_array()
$mssqlResult = mssql_query($query);
// connect to the MySQL database
mysql_connect("**Host**", "**username**", "**password**") or die(mysql_error());
mysql_select_db("Database_Name") or die(mysql_error());
while ( $mssqlRow = mssql_fetch_array($mssqlResult) ) {
$mssqlCode = $mssqlRow['code'];
$mssqlOnHand = $mssqlRow['onhand'];
mysql_query(
"UPDATE product_option_value SET quantity = $mssqlOnHand WHERE ob_sku = $mssqlCode"
// extra quotes may be required around $mssqlCode depending on the column type
);
}
In my php script which connects to mysql, I have to query 2 databases in the same script to get different information. More specifically Faxarchives in one database and Faxusers in the other.
In my code I query faxusers and then foreach user, I query Faxarchives to get the user history.
I might do something like:
function getUserarchive( $userid) {
$out= "";
$dbname = 'Faxarchive';
$db = mysql_select_db($dbname);
$sql = "select sent, received from faxarchivetable where userid = '" . $userid . "'";
if ( $rs = mysql_query($sql) {
while ($row = mysql_fetch_array($rs) ) {
$out = $row['sent'] . " " . $row['received'];
}//end while
}//end if query
return ($out);
}//end function
$conn = mysql_connect($dbhost, $dbuser, $dbpass) or die ('Error connecting to mysql');
$dbname = 'Faxusers';
$db = mysql_select_db($dbname);
$sql="select distinct userid from faxuserstable";
if ( $rs = mysql_query($sql) {
while ($row = mysql_fetch_array($rs) ) {
$out = $row['userid'] . ":" . getuserarchive($row['userid']);
}//end while
}//end if query
I'm guessing the switching between databases for each user is causing the slowness. Anyways how i can improve the speed of the processing?
thanks in advance.
You have several problems. First, your function, getUserarchive, pulls back all rows all the time. Looks like you forgot to restrict your SQL to only a specific userid. That's a big cause of your speed issues.
Another option would be to pass in all userids you are interested in. Rewrite the SQL as SELECT sent, received FROM faxarchivetable WHERE userid IN (...), which means you'd have one select to pull back all info from your faxarchivetable, instead of one per each userid.
Finally, if both databases are on the same MySQL server, you could just do a single select to pull in all the information:
SELECT Faxusers.faxuserstable.userid, sent, received FROM Faxusers.faxuserstable JOIN Faxarchive.faxarchivetable ON Faxusers.faxuserstable.userid = Faxarchive.faxarchivetable.userid
Are you aware that you can query tables in separate databases by qualifying the tablename?
For example, I think you can get all your information in a single SQL query like this:
SELECT sent, received
FROM Faxarchive.faxarchivetable
WHERE userid IN ( SELECT DISTINCT userid FROM Faxusers.faxuserstable );
Oh, this is the same point ChrisInEdmonton makes. I didn't notice his answer.