Forgive me if my question sounds stupid as I'm a begginer with SQLite, but I'm looking for the simplest SQLite query PHP solution that will give me full text results from at least three separate SQLite databases.
Google seems to give me links to articles without examples and I have to start from somewhere.
I have three databases:
domains.db (url_table, title_table, date_added_table)
extras.db (same tables as the first db)
admin.db (url_table, admin_notes_table)
Now I need a PHP query script that will execute a query and give me results from domains.db but if there are matches also from extras.db and admin.db.
I'm trying to just grasp the basics of it and looking for a starting point where I can at least study and learn the first code.
First, you connect to 'domains.db', query what you need, save however you want, than if there were a result in the first query, you connect to the others and query them.
$db1 = new SQLite3('domains.db');
$results1 = $db1->query('SELECT bar FROM foo');
if ($results1->numColumns() && $results1->columnType(0) != SQLITE3_NULL) {
// have rows
// so, again, $result2 = $db2->query('query');
// ....
} else {
// zero rows
}
// You can work with the data like this
//while ($row = $results1->fetchArray()) {
// var_dump($row);
//}
Source:
http://php.net/manual/en/sqlite3.query.php
http://php.net/manual/en/class.sqlite3result.php
Edit.: A better approach would be to use PDO, you can find a lot of tutorials and help to use it.
$db = new PDO('sqlite:mydatabase.db');
$result = $db->query('SELECT * FROM MyTable');
foreach ($result as $row) {
echo 'Example content: ' . $row['column1'];
}
You can also check the row count:
$row_count = sqlite_num_rows($result);
Source: http://blog.digitalneurosurgeon.com/?p=947
Related
I want to run multiple sql queries in a single database connection using oracle 10g and php. Here for every sql query queries I have to create database connection. Is there any way to run multiple sql queries in a single database connection or we have to fetch data this way only? Because when we have to run 50 queries, we have to write 50 times like below.
<?php
include("mydb.php");
// run query
$sql6 = "select * from dat where to_char(WD,'dd/mm')='19/08'";
$stid6=oci_parse($conn, $sql6);
// set array
$arr6 = array();
if(!$stid6){
$e=oci_error($conn);
trigger_error(htmlentities($e[message],ENT_QUOTES),E_USER_ERROR);
}
$r6=oci_execute($stid6);
if(!$r6){
$e=oci_error($stid6);
trigger_error(htmlentities($e[message],ENT_QUOTES),E_USER_ERROR);
}
// look through query
while($row = oci_fetch_array($stid6,OCI_ASSOC)){
// add each row returned into an array
$arr6[] = array(($row['WD']) , (float)$row['DATA']);
}
oci_free_statement($stid6);
oci_close($conn);
?>
<?php
include("mydb.php");
// run query
$sql7 = "select * from dat where to_char(WD,'dd/mm')='11/03'";
$stid7 = oci_parse($conn, $sql7);
// set array
$arr7 = array();
if(!$stid7){
$e=oci_error($conn);
trigger_error(htmlentities($e[message],ENT_QUOTES),E_USER_ERROR);
}
$r7=oci_execute($stid7);
if(!$r7){
$e=oci_error($stid7);
trigger_error(htmlentities($e[message],ENT_QUOTES),E_USER_ERROR);
}
// look through query
while($row = oci_fetch_array($stid7,OCI_ASSOC)){
// add each row returned into an array
$arr7[] = array(($row['WD'])) , (float)$row['DATA']);
}
oci_free_statement($stid7);
oci_close($conn);
?>
................
................
*Pardon me, I forgot to mention that we have store day-wise data in different array. I mean to say that 11/03's data will store in arr1 and 19/08's data will be stored in arr2. Not in same array.
(this should be a comment, but its a bit long)
I don't want to be disparaging here, but your question is alarming naive - so much so that it should be closed as off-topic.
Your code exhibits a lack of understanding about modular programming and variable scope. These should be covered by day 2 of a programming-from-scratch course. but oddly includes some more sophisticated PHP specific programming, but apalling SQL - it looks like someone else wrote the code as a quick hack and now you are trying to extend its capabilities.
That you are using an Oracle database, raises all sorts of questions about why are attempting this (Oracle is expensive; how can someone afford that but not afford to provision you with the skills you need?)
The solution to the problem as you have described it is to re-implement the script as a function that takes the OCI connection and SQL statement as parameters, then simply....
<?php
include("mydb.php");
$queries=array(
"select * from dat where to_char(WD,'dd/mm')='11/03'",
"select * from dat where to_char(WD,'dd/mm')='19/08'"
);
foreach ($queries as $sql) {
run_qry($sql, $conn);
}
oci_close($conn);
exit;
function run_query($sql, $conn)
{
$stid=oci_parse($conn, $sql);
// set array
$arr = array();
if(!$stid){
$e=oci_error($conn);
trigger_error(htmlentities($e[message],ENT_QUOTES),E_USER_ERROR);
}
...
oci_free_statement($stid);
return $arr;
}
However since the 2 example queries have exactly the same structure, there are other ways to the results of what are multiple queries - merging the SQL states into a single select using OR or UNION, using parameterized queries. Since the code you've shown us simply throws away the results its hard to say how you should approach the task.
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 was wondering if you think this is possible:
Ok so I have a database storing usernames and I would like to echo the admins which are inside a file called admins.php IF they match the usernames inside the database so far I have got:
admins.php;
$admins = array("username","username2","username3");
and
$users="SELECT username from usrsys";
$query_users=mysql_query($users);
while loop here.
The while loop should hopefully echo the users which matches the admins.php file. I assume I should use something like (inarray()), but I am really not sure.
You should definitely use IN clause in your SQL to do this. Selecting everything from the table in order to determine in PHP if it contains the user names you're looking for makes no sense and is very wasteful. Can you imagine what would happen if you had a table of 1 million users and you needed to see if two of them were on that list? You would be asking your DBMS to return 1 million rows to PHP so that you can search through each of those names and then determine whether or not any of them are the ones you're looking for. You're asking your DBMS to do a lot of work (send over all the rows in the table), and you're also asking PHP to do a lot of work (store all those rows in memory and compute a match), unnecessarily.
There is a much more efficient and faster solution depending on what you want.
First, if you only need to know that all of those users exist in the table then use SELECT COUNT(username) instead and your database will return a single row with a value for how many rows were found in the table. That way you have an all or nothing approach (if that's what you're looking for). Either there were 3 rows found in the table and 3 elements in the array or there weren't. This also utilizes your table indexes (which you should have properly indexed) and means faster results.
$admins = array("username","username2","username3");
// Make sure you properly escape your data before you put in your SQL
$list = array_map('mysql_real_escape_string', $admins);
// You're going to need to quote the strings as well before they work in your SQL
foreach ($list as $k => $v) $list[$k] = "'$v'";
$list = implode(',', $list);
$users = "SELECT COUNT(username) FROM usrsys WHERE username IN($list)";
$query_users = mysql_query($users);
if (!$query_users) {
echo "Huston we have a problem! " . mysql_error(); // Basic error handling (DEBUG ONLY)
exit;
}
if (false === $result = mysql_fetch_row($query_users)) {
echo "Huston we have a problme! " . mysql_error(); // Basic error handling (DEBUG ONLY)
}
if ($result[0] == count($admins)) {
echo "All admins found! We have {$result[0]} admins in the table... Mission complete. Returning to base, over...";
}
If you actually do want all the data then remove the COUNT from the SQL and you will simply get all the rows for those users (if any are found).
$admins = array("username","username2","username3");
// Make sure you properly escape your data before you put in your SQL
$list = array_map('mysql_real_escape_string', $admins);
// You're going to need to quote the strings as well before they work in your SQL
foreach ($list as $k => $v) $list[$k] = "'$v'";
$list = implode(',', $list);
$users = "SELECT username FROM usrsys WHERE username IN($list)";
$query_users = mysql_query($users);
if (!$query_users) {
echo "Huston we have a problem! " . mysql_error(); // Basic error handling (DEBUG ONLY)
exit;
}
// Loop over the result set
while ($result = mysql_fetch_assoc($query_users)) {
echo "User name found: {$result['username']}\n";
}
However, I really urge you to reconsider using the old ext/mysql API to interface with your MySQL database in PHP since it is deprecated and has been discouraged from use for quite some time. I would really urge you to start using the new alternative APIs such as PDO or MySQLi and see the guide in the manual for help with choosing an API.
In PDO, for example this process would be quite simple with prepared statements and parameterized queries as you don't have to worry about all this escaping.
There's an example in the PDOStatement::Execute page (Example #5) that shows you just how to do use the IN clause that way with prepared statements... You can then reuse this statement in other places in your code and it offers a performance benefit as well as making it harder for you to inadvertently expose yourself to SQL injection vulnerabilities.
// Connect to your database
$pdo = new PDO("mysql:dbname=mydb;host=127.0.0.1", $username, $password);
// List of admins we want to find in the table
$admins = array("username","username2","username3");
// Create the place holders for your paratmers
$place_holders = implode(',', array_fill(0, count($admins), '?'));
// Create the prepared statement
$sth = $dbh->prepare("SELECT username FROM usrsys WHERE username IN ($place_holders)");
// Execute the statement
$sth->execute($admins);
// Iterate over the result set
foreach ($sth->fetchAll(PDO::FETCH_ASSOC) as $row) {
echo "We found the user name: {$row['username']}!\n";
}
Your PHP code even looks so much better with PDO :)
Just include admins.php file and use the next construction in your loop:
while ($row = mysql_fetch_array($users)) {
if (in_array($users[0], $admins))
echo $users[0];
}
Try this:
<?php
# include admins.php file that holds the admins array
include "admins.php";
# join all values in the admins array using "," as a separator (to use them in the sql statement)
$admins = join(",", $admins);
# execute the query
$result = mysql_query("
SELECT username
FROM usrsys
WHERE username IN ($admins)
");
if ($result) {
while ($row = mysql_fetch_array($result)) {
echo $row["username"] . "<br>";
}
}
?>
If your looking for syntax to pull in only the users from your $admins array then you could use something like:
$users="SELECT username FROM usrsys WHERE username IN ('".join("','",$admins)."')";
Where the php function JOIN will print username,username2,username3. Your resulting MySQL statement will look like:
SELECT username FROM usrsys WHERE username IN ('username','username2','username3')
Alternatively, if your looking to iterate through your $query_vars array and separate your admins from non-admins then you could use something like:
<?php
while($row = mysql_fetch_assoc($query_users)){
if(in_array($row['username'],$admins)){
//do admin stuff here
}else{
//do NON-admin stuff here
}
}?>
Well i've been searching google, but I still can't find out how to do this.
I'm a beginner in php so i'm really stumped.
Anyways what I need to do is get all the data from a table and display it on my page.
Like
Contents of row 1
Contents of row 2
etc.
Well that's nice, get down voted for asking for help.
This might help you
print_r() displays information about a variable in a way that's readable by humans.
print_r(), var_dump() and var_export() will also show protected and private properties of objects with PHP 5. Static class members will not be shown.
Remember that print_r() will move the array pointer to the end. Use reset() to bring it back to beginning.
http://php.net/manual/en/function.print-r.php
This is pretty much PHP DB access 101
$pdo = new PDO('mysql:host=localhost;dbname=myDbName', 'username', 'password');
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$stmt = $pdo->prepare('SELECT * FROM a_table');
$stmt->execute();
$resultSet = $stmt->fetchAll(PDO::FETCH_ASSOC);
foreach ($resultSet as $idx => $row) {
echo '<p>Contents of row ', $idx + 1, '</p><dl>';
foreach ($row as $col => $val) {
printf('<dt>%s</dt><dd>%s</dd>',
htmlspecialchars($col),
htmlspecialchars($val));
}
echo '</dl>';
}
I think google should have given you your answer since this is a rather easy to answer question, but when starting, you don't always know what to search for.
Anyways, hope this helps.
<?php
// connect with you database, returns boolean so you know if you succeeded or not
$con = mysql_connect($database,$username,$password);
if(!$scon){
die('Could not connect to database'); // Stop execution if connection fails
}
//create your query
$query = "Place your database query here";
//get the results
$result = mysql_query($query);
//now you want to go through each row of the result table and echo the contents, or
//use them for whatever reason
while($row = mysql_fetch_array($result)){
echo $row['field_you_want_to_display'];
echo $row['another_field_you_want_to_display']; //You see where this is going
}
//After doing what you want, close the connection to the database
mysql_close($con);
?>
Also, you may want to take a look at the documentation of php for find out what functions you have not seen before do.
I want to show all text messages from db where id=$e ($err is an array).
Inserted the query into the foreach loop, it works well but it does extra work (does query for every value of array).
Is there any other way to do it (i mean extract query from foreach loop)?
My code looks like this.
foreach ($err as $e)
{
$result = $db -> query("SELECT * from err_msgs WHERE id='$e'");
$row = $result -> fetch_array(MYSQLI_BOTH);
echo "<li><span>".$row[1]."</span></li>";
}
It is much more efficient to do this with implode() because it will only result in one database query.
if (!$result = $db->query("SELECT * FROM `err_msgs` WHERE `id`='".implode("' OR `id`='",$err)."'")) {
echo "Error during database query<br />\n";
// echo $db->error(); // Only uncomment this line in development environments. Don't show the error message to your users!
}
while ($row = $result->fetch_array(MYSQLI_BOTH)) {
echo "<li><span>".$row[1]."</span></li>\n";
}
Check the SQL IN clause.
Firstly, a bit of a lecture: embedding strings directly into your queries is going to cause you trouble at some point (SQL injection related trouble to be precise), try to avoid this if possible. Personally, I use the PDO PHP library which allows you to bind parameters instead of building up a string.
With regard to your question, I'm not sure I have understood. You say that it does extra work, do you mean that it returns the correct results but in an inefficient way? If so then this too can be addressed with PDO. Here's the idea.
Step 1: Prepare your statement, putting a placeholder where you currently have '$e'
Step 2: Loop through $err, in the body of the loop you will set the place holder to be the current value of $e
By doing this you not only address the SQL injection issue, you can potentially avoid the overhead of having to parse and optimise the query each time it is executed (although bear in mind that this may not be a significant overhead in your specific case).
Some actual code would look as follows:
// Assume that $dbdriver, $dbhost and $dbname have been initialised
// somewhere. For a mysql database, the value for $dbdriver should be
// "mysql".
$dsn = "$dbdriver:host=$dbhost;dbname=$dbname";
$dbh = new PDO($dsn, $dbuser, $dbpassword);
$qry = "SELECT * from err_msgs WHERE id = :e"
$sth = $dbh->prepare($qry);
foreach ($err as $e) {
$sth->bindParam(":e", $e);
$sth->execute();
$row = $sth->fetch();
// Prints out the *second* field of the record
// Note that $row is also an associative array so if we
// have a field called id, we could use $row["id"] to
// get its value
echo "<li><span>".$row[1]."</span></li>";
}
One final point, if you want to simply execute the query once, instead of executing it inside the loop, this is possible but again, may not yield any performance improvement. This could be achieved using the IN syntax. For example, if I'm interested in records with id in the set {5, 7, 21, 4, 76, 9}, I would do:
SELECT * from err_msgs WHERE id IN (5, 7, 21, 4, 76, 9)
I don't think there's a clean way to bind a list using PDO so you would use the loop to build up the string and then execute the query after the loop. Note that a query formulated in this way is unlikely to give you any noticable performance improvment but it really does depend on your specific circumstances and you'll just have to try it out.
You can do this much simpler by doing
$err_csv = implode("','",$err);
$sql = "SELECT FROM err_msgs WHERE id IN ('$err_csv')";
$result = $db -> query($sql);
while ($row = $result -> fetch_array(MYSQLI_BOTH))
{
echo "<li><span>".$row[1]."</span></li>";
}
That way you don't have to keep sending queries to the database.
Links:
http://php.net/manual/en/function.implode.php