I have two tables which is
+----------------------------+
| task |
+----------------------------+
| id | t_title | t_assign_to |
+----------------------------+
+-----------------------------+
| task_employee |
+-----------------------------+
| id | emp_name | emp_underon |
+-----------------------------+
My question is that i want to fetch t_assign_to FROM task table which having emp_underon = '2' in task_employee table with foreign key (t_assign_to)
<?php
$sql = mysql_query("SELECT * FROM task");/// i got all value from here
$sql=mysql_query("SELECT * FROM task_employee WHERE emp_underon ='2'");// i got all value from here
//$sql=mysql_query("SELECT * FROM task UNION SELECT * FROM task_employee WHERE emp_underon='2'");
$count = mysql_num_rows($sql);
while($row=mysql_fetch_assoc($sql))
{
echo $row['t_assign_to'];
}
?>
I think the t_assign_to is the foreign key for task_employee
So i JOIN them together
Schema 1
$sql = "SELECT * FROM task t INNER JOIN task_employee te ON t.t_assign_to = te.id";
Schema 2
$sql = "SELECT * FROM task t,task_employee te WHERE t.t_assign_to = te.id";
If the field name in table is same with others field in others table, just alter the field name like:
$sql = "SELECT table.field as new_field_name FROM task t,task_employee te WHERE t.t_assign_to = te.id";
For you convenient,
$sql = "SELECT * FROM task t INNER JOIN task_employee te ON t.t_assign_to = te.id WHERE te.emp_underon = '2' "
$q = mysql_query($sql);
$c = mysql_num_rows($q);
if($c > 0)
{
while($r = mysql_fetch_assoc($q))
{
echo $r['t_assign_to'];
}
}
I hope you can get your answer by this query though I did not test this SQL.
select task.t_title, task.t_assign_to, task_employee.id as emp_id, task_employee.emp_name from task inner join task_employee on task.t_assign_to = task_employee.emp_underon where task_employee.emp_underon = 2
Related
I have two MySQL tables:
offers:
id | rid | name
------------------------------
1 | 1234 | mary
2 | 1235 | john
3 | 5342 | liam
And
geo_in_off:
offer_id | geo_id
------------------------------
1 | 1234
2 | 1235
3 | 5342
I need to make a table on my website looging like:
1(number) | 1234(rid) | name(name) | 1(geo_id)
But I got MySQL troubles.
My code is:
require('../config.php');
echo "<table class=\"offer-table\">";
echo "<tr><th id=\"off_col_num\">№</th><th id=\"off_col_id\">offer ID</th><th id=\"off_col_name\">Название</th><th id=\"off_col_geo\">Geo</th></tr>";
$i = 1;
$sql ="SELECT * FROM `offers` ORDER BY `rid` JOIN geo_in_off ON geo_in_off.id = offers.id";
$result = mysql_query($sql) or die(mysql_error());
while ($row=mysql_fetch_assoc($result)) {
echo "<tr><td>" . $i . "</td><td>" . $row['rid'] . "</td><td>" .
$row['name'] . "</td><td>" .$i . "</td></tr>" ;
$i++;
}
echo "</table>";
I've got problems with MySQL synaxis and the logic how to get the data from 2 tables and give the result in one "while loop".
So I need to join 2 queries in one:
$sql ="SELECT * FROM `offers` ORDER BY `rid`";
$sql ="SELECT `geo_id` FROM `geo_in_off` WHERE `offer_id` = '$each_offer_id_from_offers'";
And optional but not necessary:
$sql ="SELECT `name` FROM `geo` WHERE `id` = '$geo_id_got_from_table_geo_in_off'";
And get a table where I get the offer id, the offer name and the offer geo.
Try this query, it does help you (full join query)
SELECT offers.*, geo_in_off.geo_id FROM offers,
geo_in_off WHERE offers.id=geo_in_off.offer_id
Change
$sql ="SELECT * FROM `offers` ORDER BY `rid` JOIN geo_in_off ON geo_in_off.id = offers.id";
To
$sql ="SELECT * FROM `offers` JOIN `geo_in_off` ON `geo_in_off`.`offer_id` = `offers`.`id` ORDER BY `offers`.`rid`";
1) ORDER BY order is wrong in your query
SELECT column1, column2, ...
FROM table_name
ORDER BY column1, column2, ... ASC|DESC;
2) Instead of geo_in_off.id = offers.id use geo_in_off.offer_id = offers.id
Try this query:
$sql = 'SELECT of.id, of.rid, of.name, geo.id
FROM of.offers
INNER JOIN of.id = geo.offer_id
WHERE offer_id = \''.$each_offer_id_from_offers.'\' order by of.rid'
I have a query in mySQL
SELECT id FROM admin_products;
which return a list of ids, like so
+------+
| id |
+------+
| 1 |
| 2 |
| 3 |
| 4 |
| 5 |
+------+
And I was using PHP to dynamically generate tables like
vendor_1, vendor_2, vendor_3, vendor_4, vendor_5
Now I want to write a query to retrieve the price and quantity from the table id
For example
"ENTER QUERY HERE"
Should retrieve
+-----------------------------+
| id | price | quantity |
+-----------------------------+
| 1 | 23| 13| // price and quantity retrieved from table vendor_1 since id=1
| 2 | 158| 85| // price and quantity retrieved from table vendor_2 since id=2
| 3 | 15| 7| // price and quantity retrieved from table vendor_3 since id=3
| 4 | 112| 9| // price and quantity retrieved from table vendor_4 since id=4
| 5 | 123| 199| // price and quantity retrieved from table vendor_5 since id=5
+-----------------------------+
What I'm doing now in PHP is:
$conn = mysqli_connect($server,$user,$pwd,$db);
$sql = "SELECT id FROM admin_products";
$res = mysqli_query($conn,$sql);
if(mysqli_num_rows($res)>0){
while($row = mysqli_fetch_assoc($res)){
$product = array();
$innerSQL = "SELECT price,quantity FROM vendor_".$row['id'];
$innerRes = mysqli_query($conn,$innerSQL);
if(mysqli_num_rows($innerRes)>0){
while($innerRow = mysqli_fetch_assoc($innerRes)){
array_push($product,$row['id']);
array_push($product,$innerRow['price']);
array_push($product,$innerRow['quantity']);
}
}
}
}
But it takes two hits to the mySQL database. Can't it be reduced to one?
EDIT
I have later on realized that my database structure was incorrect and dynamically creating tables is a very bad idea and could spell disaster later on
-Solution 1:
Note: This will only work if you have in your vendor_x tables id for the vendor id to match them with. (As Strawberry said, this is a terrible idea to dynamically generate tables).
After selecting the correct id you can do something like this:
connect to the MySql Server
Then you can create the table name and store it in a variable.
$tableName = 'vendor_' . $id;
I would suggest after that to have a check if the table exists with a simple query:
$sql = "SHOW TABLES LIKE '$tableName'";
If this returns empty result you can throw an exception that the table does not exist or handle it whatsoever way you would like.
After checking every table, to be sure it exists, you can create your query.
$joins = "";
$sql = "
SELECT
v.id,
price,
quantity
FROM
vendors AS v
";
foreach ($ids as $id) {
$tableName = "vendor_" . $id;
$tableAlias = "v".$id;
$joins .= " LEFT JOIN " . $tableName . " AS ". $tableAlias ."
ON (v.id = ". $tableAlias .".vendor_id) ";
}
$sql .= $joins;
Then execute the query.
-Solution 2:
Create only one table to manage your vendors. It should have a structure like this :
`id` // AI value
`vendor_id` // The id of the vendor to easily join it afterwards
`price`
`quantity`
You can name it something like vendor_product or whatsoever
And now you have only one simple query:
$sql = "
SELECT
v.id,
vp.quantity,
vp.price
FROM
vendors AS v
LEFT JOIN vendor_product AS vp
ON (vp.vendor_id = v.id)
";
EDIT for the comment about the structure:
You will need one table for the vendors, such so:
`vendor`:
`id`, //AI value
`username`,
`password` // I suggest to you not to keep it in plain text.
`vendor_product` :
`id`, //AI value
`vendor_id`,
`price`,
`quantity`
I don't know here if you are going to store more information about each product, but this should do the trick.
How to show the product with least price ?
You need to match them by somehow and group by that selecting minimum price.
Try this if it suits
$table = "vendor"."_".$id; // this will create table name if $id = 1 then $table = vendor_1;
mysqli_query($connect , "SELECT * FROM $table");
2nd
If you want to fetch data of all table at once then
1) fetch id from admin_products and store in an array like
$ids = array(1,2,3,4,5);
2) Now loop throw array and create sql;
$sql = "SELECT * FROM ";
$ids = array(1,2,3,4,5);
foreach($ids as $id){
$table = "vendor"."_".$id; // this will create table name if $id = 1 then $table = vendor_1;
$sql .=" $table,";
}
$sql = rtrim($sql,",");// this will trim the last comma
echo $sql;
// output SELECT * FROM vendor_1, vendor_2, vendor_3, vendor_4, vendor_5
I have two tables:
1 - hotels[id,name,extras] ( name of hotels with column extras which I've select for each one)
2 - extras[id,name] ( here's the extras of hotel like wifi,tv,swim... )
$name = $_GET['name'];
$hotels_q = mysql_query("SELECT * FROM `hotels` WHERE `name`='$name'") or die (mysql_error());
$hotels_row = mysql_fetch_array($hotels_q);
$id = $hotels_row['id'];
$extras = explode(",", $hotels_row['extras']);
$ekstras_q = mysql_query("SELECT * FROM `extras` order by id") or die(mysql_error());
While($ekstras_row = mysql_fetch_array($ekstri_q)){
$eid = $ekstras_row['id'];
$ename = $ekstri_row ['name'];
echo '<ul><li><input type="checkbox" name="extras['.$eid.'][]" value="'.$ename.'"';
if (in_array($eid, $ekstras)) echo'checked';
echo'/>'.$ename.'</li></ul>';
Problem is here extras_q displays all entries with checked ones from table, but I want only to display only checked items!
Since you're storing your extra IDs in one column as a comma separated string, I think you should be able to do this by not exploding that value, and then using the CSV string as an IN criteria in your second query.
//...
$extras = $hotels_row['extras']; // don't explode
// Use IN with the $extras CSV here
$ekstras_q = mysql_query("SELECT * FROM `extras`
WHERE id IN ($extras) ORDER BY id") or die(mysql_error());
If you are able to modify your database, you can instead create a many-to-many relationship between hotels and extras by adding a table to join those two items together instead of using a CSV column as you currently are. This can make it easier to write queries to select the related records.
If you add a third table hotel_extras with columns hotel_id and extra_id, you can insert one row for each extra that each hotel has. For example, if the hotel with id 1 has several different extras, its entries in that table would look like this:
table: hotel_extras
_______________________
| hotel_id | extra_id |
=======================
| 1 | 1 |
| 1 | 3 |
| 1 | 4 |
-----------------------
Here is an example using PDO of how you could query data from a setup like that:
$sql = "SELECT e.id, e.name
FROM hotels h
INNER JOIN hotel_extras he ON h.id = he.hotel_id
INNER JOIN extras e ON he.extra_id = e.id
WHERE h.`name` = ?";
$stmt = $pdo->prepare($sql);
$stmt->bindValue(1, $_GET['name']);
$stmt->execute();
while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
$eid = $row['id'];
$ename = $row['name'];
'<li><input type="checkbox" name="extras['.$eid.'][]" value="'.$ename.'" checked/>'.$ename.'</li>';
}
This is how my table looks like:
id | name | value
-----------------
1 | user1| 1
2 | user2| 1
3 | user3| 3
4 | user4| 8
5 | user5| 6
6 | user7| 4
7 | user8| 9
8 | user9| 2
What I want to do is to select all the other users, in one query, who's value is user1's value lower than it's value plus 3, higher than it's value minus 3 or equal to it's value.
Something like this:
$result = mysqli_query($con,"SELECT * FROM users WHERE value<'4' OR value>'-2'") or die("Error: ".mysqli_error($con));
while($row = mysqli_fetch_array($result))
{
echo $row['name'].'<br/>';
}
The problem is that users1's value can vary every time the query is run.
Sorry for lame names, but this should work:
NOTE: I named table with your data as "st".
SELECT b.user, a.value as "user1val", b.value as "otheruservalue" FROM st as a
join st as b
on a.user = "user1" and a.user != b.user
where
(b.value > (a.value - 3)) and (b.value < (a.value + 3))
We get unique pairs of user1's value and other user's value by joining same table. After that we just do some simple comparison to filter rows with suitable values.
$user1 = mysql_fetch_assoc(mysql_query("SELECT `value` FROM `users` WHERE id='1'"));
$result = mysql_query("SELECT * FROM `users` WHERE value<'".$user1['value']."+3' OR value>'".$user1['value']."-3'");
Or nested queries :
$result = mysqli_query($con, "select * from `users` where `value` < (select `value` from `users` where `name`='user1')+3 OR `value` > (select `value` from `users` where `name`='user1')-3");
I have 3 columns in table1: book, key and value.
| book | key | value |
------------------------------
| 1 | author | a |
| 1 | editor | b |
| 1 | book | c |
Instead of runnuing three queries
$data = mysql_query("
SELECT * FROM table1 WHERE book = '1' AND key = 'author'
") or die(mysql_error());
while($info = mysql_fetch_array( $data ))
{
$value1 = $info['value'];
}
Then repeat this for editor and book.
$value1 $value2 $value3 are inserted in different places on page
Could I do this with one query?
Yes. If there are no other entries with "book = 1" you just query
SELECT * FROM table1 WHERE book = '1'
If there are more entries you can use this query:
SELECT * FROM table1 WHERE book = '1' AND key IN('author','editor','book')
And then create an assoc array:
while($info = mysqli_fetch_assoc( $data ))
{
$value[$info['key']] = $info['value'];
}
...
echo "the book {$value['book']} was written by {$value['author']}";
for create a $value array you have to use this :
$value[] = $info['value'];
instead of this :
$value1 = $info['value'];
Also you can use this code :
$value[]["key"] = $info['key'];
$value[]["value"] = $info['value'];
And for example you can call first row's value with $value[0]["value"]
If you want the values in a single record try this:
SELECT `t1`.`value` AS `value1`, `t2`.`value` AS `value2`, `t3`.`value` AS `value3`
FROM
`table1` AS `t1` CROSS JOIN
`table1` AS `t2` CROSS JOIN
`table1` AS `t3`
WHERE
(`t1`.`book` = 1) AND (`t1`.`key` = 'author')
AND (`t2`.`book` = 1) AND (`t2`.`key` = 'editor')
AND (`t3`.`book` = 1) AND (`t3`.`key` = 'book');