Im working with sql database (phpMyadmin) and with programming language PHP.
I've got a table with data e.g:
T1:
145
138.8
110.6
1759.4
1400.9
1891.4
1755.4
1760.4
T2:
141.9
110.6
1400.9
1891.4
1758.4
My question >
Is there existing sql syntax, that is able to average values which are lying in ONE THRESHOLD (like > 1755.4,1760.4,1759.4 OR 145,138.8) and INSERT THEM AS UNIQUE VALUES to another table ?
What I need is create T2(contain UNIQUE values) from T1, and INSERTING them only if they didn't exist in T2.
I was trying, to looping throw 2 arrays (1starray = T1 and 2ndarray = T2 ) too. And compare data in array1 and array2, and trying to insert values which can be unique.
for($z = 0; $z<$numberApp; $z++) {
while($j<$numberAbs-1){
$Abs=$arrayabs[$j];
$state_change = (abs($Abs - abs($previous_Abs)));
if ($state_change>100){
$instantChange = True;
echo "<br>"." better than tolerance: " . $instantChange;
}
else {
$instantChange = False;
echo "<br>"." lower than tolerance" . $instantChange;
}
//if($state_change = (abs($some_item - $previous_item)<= $tolerance)){
if($Abs != $previous_Abs){
echo "<br>" ." some_item : " .$Abs." previous_item : " .$previous_Abs;
}
//$lastAbs=$arrayabs[$j];
//echo " next_item : " .$lastAbs;
if ($instantChange == True and $onChange == False){
$Abs2 [] = $podiel;
$finalPower = $podiel;
}
if ($instantChange){
$D=0;
echo "ABSOLUT >>> " .$lastAbs;
$percentual1 = ($power_app[$z] * 0.9);
$percentual2 = ($power_app[$z] * 1.1);
if(($lastAbs<$percentual1 || $lastAbs>$percentual2)){
$user = 'root';
$pass = 'password';
$db = 'vypis';
//if($N>0){
$db = new mysqli('localhost', $user, $pass, $db) or die();
$sql = "INSERT INTO vypis.nilm_app2(power) VALUES ('$lastAbs')";
if(mysqli_query($db, $sql)){
echo "Records added successfully.";
} else{
echo "ERROR: Could not able to execute $sql. " . mysqli_error($db);
}
}
//$power_app[$z++];
}
Thank you for everyone, who going to help, and sorry for my bad english.
The math here sounds complex enough that you're probably better off doing the complex stuff (averaging the values and determining whether a value is unique) in PHP, then finishing off with a couple simple MySQL statements.
This can probably be done in pure MySQL with a bit of trickery, but frequently it isn't worth the time and complexity it creates. (Imagine you'll have to debug that monster SQL query six months from now!)
By contrast, it's trivial to take a handful of values in PHP and average them; it's also trivial to run a quick MySQL query to determine whether a value is unique. So if you're unsure how to mash these together into one big SQL statement, start out by just handling them in the PHP code as separate steps! Then later on, if performance issues come up, you can think about how to combine them (but at least by that point you already have something that works).
Related
My question is pretty straight-forward, and I assume that people need to do this pretty often; yet, after hours of searching online, nothing especially enlightening has come up. I am aware of a thread on here about doing the same thing using PDO, but I want to stick to mysqli to be consistent across my whole site.
So, I need to move one or several rows from one database to another (and NOT from one table to another within a single database).
The code I have so far is sure to get some laughs, as this task proved to be considerably beyond my ability. Anyway, here goes:
To begin with, I have two mysqli_connect... not sure if that is encouraged, although it has not caused me problems so far.
$connect_MAIN = mysqli_connect($servername_MAIN, $username_MAIN, $password_MAIN, $dbname_MAIN);
$connect_TEMP = mysqli_connect($servername_TEMP, $username_TEMP, $password_TEMP, $dbname_TEMP);
Here is the meat in the sandwich in terms of code:
///Prepare this in advance because the 'IN' values are taken from a $_GET
$sql_select = "SELECT * FROM Concert WHERE id IN (1, 2, 3, 4)";
///Connect to source DB
$result = $connect_TEMP->query($sql_select);
if ($result->num_rows != 0) {
///Connect to destination DB
$stmt = $connect_MAIN->prepare('INSERT INTO Concert (venue_id, date, ensemble_id, info, title, repertoire, time) VALUES (?, ?, ?, ?, ?, ?, ?)');
$venue_id = $date = $ensemble_id = $info = $title = $repertoire = $time = null;
$stmt->bind_param("isissss", $venue_id, $date, $ensemble_id, $info, $title, $repertoire, $time);
while($row = $result->fetch_assoc()) {
$venue_id = $row["venue_id"];
$date = $row["date"];
$ensemble_id = $row["ensemble_id"];
$info = $row["info"];
$title = $row["title"];
$repertoire = $row["repertoire"];
$time = $row["time"];
if ($stmt->execute() === TRUE) {
if ($show_once == 1) {
echo "Info successfully submitted.";
$show_once = 0;
}
} else {
echo "Hmm, something went wrong..." . $connect_MAIN->error;
}
}
}
$stmt->close();
mysqli_close($connect_TEMP);
}
So, I know that this is a bit of a jumble... as I said, I am not sure if it is possible to connect to DB2 in the middle of a while loop returning values from DB1. Feel free to mock, but only if you have something useful to suggest!
Use a parametrized query instead of concatenating strings.
///Prepare this in advance because the 'IN' values are taken from a $_GET
$sql_select = "SELECT * FROM Concert WHERE id IN (1, 2, 3, 4)";
///Connect to source DB
$result = $connect_TEMP->query($sql_select);
if ($result->num_rows != 0) {
///Connect to destination DB
$stmt = $connect_MAIN->prepare('INSERT INTO Concert (venue, date, info, time) VALUES (?, ?, ?, ?)');
$venue = $date = $info = $time = null;
$stmt->bind_param("ssss", $venue, $date, $info, $time);
while($row = $result->fetch_assoc()) {
$venue = $row["venue"];
$date = $row["date"];
$info = $row["info"];
$time = $row["time"];
if ($stmt->execute()) {
///This is just to stop message from appearing multiple times.
if ($show_once == 1) {
echo "Info successfully submitted.";
$show_once = 0;
}
} else {
echo "Hmm, something went wrong..." . $stmt->error;
}
}
$stmt->close();
mysqli_close($connect_TEMP);
}
Yes, you may establish a second DB connection at any point in your script. There's nothing preventing it nor there's a reason to discourage it. It's far more common than you'd think (for different reasons). However, considering the overhead that actually connecting to the database carries, I would advice you to not establish a connection on each iteration (this is the best practice, performance-wise)
What I would do:
First, connect to the source database, get the data you need
Not much to say here, you already did and it looks OK. Check, as you did, that there's at least one result before moving on. If the resultset is empty, don't go any further (exit)
If there was at least one row in the resultset, establish a connection to the destination database
Do this before starting to loop to avoid the performance penalty of establishing multiple connections. If you're looking at hundreds/thousands or more rows, you'll really notice the difference. Once the connection is established, move on
Loop through the source data and prepare the insert statements
You have a choice here. Either a) loop through the whole resultset and prepare one single insert with multiple rows which you'll insert all at once at the end of the loop or b) create a single insert (single row) on each iteration, run the insert and then move on to the next iteration.
There's reasons for and against both strategies. Choose the one that suits you better.
In algorythmical terms, your code is pretty much ready (just connect to the destination DB once before you start looping). You may benefit from using a parameterized query with bindings instead of writing the full insert string, but other than that you're pretty much there.
If you are running your own MySql server, you may do this in a simpler way using the Federated engine.
The federated table behaves like a normal table, but it stores the data in a remote database. With this engine you can do someting like this:
INSERT INTO remoteTable (values) SELECT * FROM localTable
$sqlorg = mysql_query("SELECT * FROM `organization`");
while($orgrows = mysql_fetch_array($sqlorg)) {
//$dborgid = $orgrows['org_id'];
$dborgnme = $orgrows['org_name'];
}
if ($dborgnme == $orgexist) {
echo "<script type='text/javascript'>
alert('Organization Name Already Used by other Organization');
history.back();
</script>";
} else {
$orginsrt = mysql_query("INSERT INTO `organization`(`org_id`,`org_name`,`org_desc`,`category`,`vision`,`mission`,`col_id`,`image`) VALUES ('$orgid','$orgexist','$orgdesc','$orgcat','$orgvis','$orgmis','$getcol','$image')");
echo "<script type='text/javascript'>
alert('Proceed to next Step');</script>";
//require ('orgsignup.php');
header ('Location:orgsignup2.php');
//echo "Not in the Record";
}
There are multiple issues with this question, and as such can't easily be answered - I'm writing this "answer" as a quick guide to Kio Rii and to get more information:
1) Don't use MySQL, use MySQLi for procedural DB/PHP interactions.
2)
while($orgrows = mysql_fetch_array($sqlorg)) {
//$dborgid = $orgrows['org_id'];
$dborgnme = $orgrows['org_name'];
}
The value $dborgnme will only ever hold the final value from all the rows fetched from the database. Consider reformatting the While statement to wrap outside the following if(){} ... else{}
3) Add some context and information to your question - what are you checking for? Where do values such as $orgexist come from? What events do you want to occur if a data exists or what happens if a data doesn't exist?
4) If you're only checking the name, you can better do it with a better SELECT statement as the current select is grabbing all the MySQL rows, so try
take :
$sqlorg = mysql_query("SELECT * FROM `organization`");
and turn it into
$sqlorg = mysql_query("SELECT * FROM `organization` WHERE org_name LIKE '%".$orgexist."%' ");
which will only return you rows if the names are very similar. You can then use the output of this (count of rows returned) to carry on the script logic.
5) Yes, my solution in part 4 is quick and dirty, and PDO or MySQLi prepared statements are much, MUCH better and more secure than old MySQL and variable injection into the SQL statement.
Additional debugging:
you would probably find this very useful:
$orginsrt = mysql_query("INSERT INTO `organization`(`org_id`,`org_name`,`org_desc`,`category`,`vision`,`mission`,`col_id`,`image`) VALUES ('$orgid','$orgexist','$orgdesc','$orgcat','$orgvis','$orgmis','$getcol','$image')") or die("insert fail: ".mysql_error());
This will tell you why an insert failed, if it did fail.
So I am trying to echo out how many rows there are in a table with a COUNT command, but I purposely have no rows in the table right now to test the if statement, and it is not working, but worst, it makes the rest of the site not work(the page pops up but no text or numbers show up on it), when I added a row to the table, it worked fine, no rows = no work. Here is the piece of the code that doesn't work. Any and all help is highly appreciated.
$query1 = mysql_query("
SELECT *, COUNT(1) AS `numberofrows` FROM
`table1` WHERE `user`='$username' GROUP BY `firstname`,`lastname`
");
$numberofrowsbase = 0;
while($row = mysql_fetch_assoc($query1))
{
if(isset($row['numberofrows']))
{
$enteries1 = $enteries1;
}else{
$enteries1 = $numberofrowsbase;
}
echo enteries1;
}
Seems you have over complicated everything. Some good advise from worldofjr you should take onboard but simplest way to get total rows from a table is:
SELECT COUNT(*) as numberofrows FROM table1;
There are several other unnecessary lines here and the logic is all bonkers. There is really no need to do
$enteries1 = $enteries1;
This achieved nothing.
Do this instead:
while($row = mysql_fetch_assoc($query1))
{
if(isset($row['numberofrows']))
{
echo $row['numberofrows'];
}
}
Maybe against my better judgement, I'm going to try and give you an answer. There's so many problems with this code ...
Do Not Use mysql_
The mysql_ extension is depreciated. You should use either mysqli_ or PDO instead. I'm going to use mysqli_ here.
SQL Injection
Your code is wide open to SQL injection where others can really mess up your database. Read How can I prevent SQL injection in PHP? for more information.
The Code
You don't need to count the rows with a SQL function, especially if you want to do something else with the data you're getting with the query (which I assume you are since you're getting a count on top of all the columns.
In PHP, you can get how many rows are in a result set using a built in function.
So all those things together. You should use something like this;
// Connect to the database
$mysqli = new mysqli($host,$user,$pass,$database); // fill in your connection details
if ($mysqli->connect_errno) echo "Error - Failed to connect to database: " . $mysqli->connect_error;
if($query = $mysqli->prepare("SELECT * FROM `table1` WHERE `user`=?")) {
$query->bind_param('s',$username);
$query->execute();
$result = $query->get_result();
echo $result->num_rows;
}
else {
echo "Could not prepare query: ". $mysqli->error;
}
The number of rows in the result is now saved to the variable $result->num_rows, so you can use just echo this if you want, like I have in the code above. You can then go onto using any rows you got from the database. For example;
while($row = $result->fetch_assoc()) {
$firstname = $row['firstname'];
$lastname = $row['lastname'];
echo "$firstname $lastname";
}
Hope this helps.
I'm looking to enter in a whole object of information. The data itself needs to be put into different tables so I'm using a mysqli_multi_query
Query
for($i=0;$i<$commLength;$i++){
$sql = "INSERT INTO
calinfo (Sbefore, Safter, A1, A2, CalGas, Factor, Zbefore, Zafter, Cbefore, Cafter, SysInfoID)
VALUES
('{$comm[$i]->ScB4}', '{$comm[$i]->ScA4}', '{$comm[$i]->A1}', '{$comm[$i]->A2}', '{$comm[$i]->CalGasA}', '{$comm[$i]->Factor}', '{$comm[$i]->ZB4}', '{$comm[$i]->ZA4}', '{$comm[$i]->CalB4}', '{$comm[$i]->CalA4}', '{$comm[$i]->CHNoID}');";
$sql .= "UPDATE
jobs
SET
CompletedBy = $tech
WHERE JobID = '{$comm[$i]->JobID}';";
if(!mysqli_multi_query($con,$sql))
{
die('Error: ' . mysqli_error($con));
}
else
{
$synctotal++;
}
}
I think I'm doing this wrong. All the data and values and being read correctly but I get this error code:
'Error: Commands out of sync; you can't run this command now'
Could someone point me in the right direction with this one please =)
Did you try running two sql queries as separate statements? rather than keeping them in 1 SQL string variable?
I am really trying to wrap my head around this and failing miserably. What I want to do it build a MySQL query based on the URL parameters passed by the URL. I am trying to create a re usable dynamic script that can do what it needs to do based on the URL parameter.
This is what I have come up with, and it appears that it does what it is supposed to do (no errors or anything) but nothing actually gets inserted in the database. I know somewhere I have made a dumb mistake (or thought something out wrong) so hopefully one of you guys can point me in the right direction.
Thanks!
//List all possible variables you can expect the script to receive.
$expectedVars = array('name', 'email', 'score', 'age', 'date');
// This is used for the second part of the query (WHERE, VALUES, ETC)
$fields = array('uName','uEmail','uScore','uAge','uDate');
// Make sure some fields are actually populated....
foreach ($expectedVars as $Var)
{
if (!empty($_GET[$Var]))
{
$fields[] = sprintf("'%s' = '%s'", $Var, mysql_real_escape_string($_GET[$Var]));
}
}
if (count($fields) > 0)
{
// Construct the WHERE Clause
$whereClause = "VALUES " . implode(",",$fields);
//Create the SQL query itself
$sql = ("INSERT INTO $mysql_table ($fields) . $whereClause ");
echo "1"; //It worked
mysql_close($con);
}
else
{
// Return 0 if query failed.
echo "0";
}
?>
You missed mysql_query($sql):
if(!mysql_query($sql)){
//die(mysql_error());
}
Please consider to use PDO or My SQLi using parametrize query because mysl_* function depreciated.
Your SQL is all wrong. You're using the field = value syntax for an INSERT, then you're concatenating an array as if it were a string ($fields), and you're missing a couple of parentheses around the values.
a couple of things: i've found for php <-> mysql its important to see what's going into mysql and experiement directly with those queries in phpmyadmin when i get stuck.
1 - in my code I output mysql_error() when the query fails or when a debug flag is set. this usually explains the sql issue in a way that can point me to a misspelled field name etc...
2 - this way i can feed that mysql query directly into phpmyadmin and tweak it until it gives me the results i want. (while i'm there i can also use explain to see if i need to optimize the table)
specifics in your code. unlike C languages sprintf is implied. here's how i'd write your code:
// List all possible variables you can expect the script to receive.
$expectedvars = array('name', 'email', 'score', 'age', 'date');
// This is used for the second part of the query (WHERE, VALUES, ETC)
// $fields = array('uName','uEmail','uScore','uAge','uDate');
$fields = array();
// Set only the variables that were populated ...
foreach ($expectedvars as $var) {
if (!empty($_GET[$var])) {
$name = "u" + ucwords($var); // convert var into mysql field names
$fields[] = "{$name} = " . mysql_real_escape_string($_GET[$var]);
}
}
// only set those fields which are passed in, let the rest use the mysql default
if (count($fields) > 0) {
// Create the SQL query itself
$sql = "INSERT INTO {$mysql_table} SET " . implode("," , $fields);
$ret = mysql_query($sql);
if (!$ret) {
var_dump('query_failed: ', $sql, $ret);
echo "0"; // Query failed
} else {
echo "1"; // It worked
}
} else {
// Return 0 if nothing to do
echo "0";
}
mysql_close($con);