Sorry let me revise. I have a three tables:
events_year
• EventID
• YearID
• id
Date
• YearID
• Year
Event
• EventID
• EventName
• EventType
i want to dispay a record from the three tables like so:
EventName - Year: Marathon - 2008
i linked it to a table called "members" which contains a ID number field (members-id)
so i can limit the results to members id = $un(which is a username from a session)
I need to join the three tables and limit the results to the specific ID number record
Here is my portion of the code:
$query = "SELECT * FROM members JOIN events_year ON members.id = events_year.id ";
"SELECT * FROM Event JOIN events_year ON Event.EventID = events_year.EventID WHERE username = '$un'";
"SELECT * FROM Date JOIN events_year ON Date.YearID = events_year.YearID WHERE username = '$un'";
$results = mysql_query($query)
or die(mysql_error());
while ($row = mysql_fetch_array($results)) {
echo $row['Year'];
echo " - ";
echo $row['Event'];
echo "<br>";
}
the notices are almost self-explaining. There are no 'Year' and 'EventName' fields in the resultset. It's difficult (or: impossible) to tell why this happens as you haven't given your table-structure, but i guess this: 'Year' is a field of the date-table, 'EventName' is a field of the event-table - you're only selecting from members so this fields don't occur.
I don't understand why there are three sql-statements but only one is assigned to a variable - the other two are just standing there and do nothing. Please explain this and put more information into your question about what you're trying to achive, what your table-structure looks like and whats your expected result.
I think what you really wanted to do is some kind of joined query, so please take a look at the documentation to see how this works.
finally, i think your query should look like this:
SELECT
*
FROM
members
INNER JOIN
events_year ON members.id = events_year.id
INNER JOIN
Event ON Event.EventID = events_year.EventID
INNER JOIN
´Date´ ON ´Date´.YearID = events_year.YearID
WHERE
members.username = '$un'
Does the field 'Year' exist in the query output ? I suspect not.
the string $query is only using the first line of text:
"SELECT * FROM members JOIN events_year ON members.id = events_year.id ";
and not the others.
The query itself is not returning any fields that are called Year or EventName.
Do a var_dump($row) to find out what is being returned.
Related
i have a question. my english isn't well. so i hope i explain well...
i have two tables, tbl_home and tbl_office, the question is
how do i make a select statement from 2 tables which have identical value from column 'case_no' where it is referenced in both table..
$a=$_POST['home_id']
the code above is where i get the home_id from,
while the statement below is how i try to select both tables based on value in column 'case_no' of both table. but it is based on variable $a which i retrieved from form
<?php
$sql2 = "SELECT * FROM tbl_office WHERE case_no IN (SELECT * FROM tbl_home WHERE home_id = '$
$result2=$conn->query($sql2);
while($row = $result2->fetch_assoc()){
$a=$row['case_no'];
$bc=$row['colour'];
echo " $a <br/> ";
echo " $bc2 <br/>";
?>
is the select statement above correct??
soo, i just want anybody to take a look a this specific statement and how to make it right
$sql2 = "SELECT * FROM tbl_office WHERE case_no IN (SELECT * FROM tbl_home WHERE home_id = '$a'";
You need inner join to use:
" SELECT t_office.home_id,t_office.case_no,t_office.name FROM tbl_office
t_office INNER JOIN tbl_home t_home ON t_office.case_no = t_home.case_no;
where t_office.case_no ='$a'";
u can use "inner join" for example:
"SELECT t.home_id,t.case_no,t.name FROM tbl_office
t INNER JOIN tbl_home h ON h.case_no = h.case_no"
**select tbl_home.name,tbl_office.case_no,tbl_office.color from tbl_office
INNER JOIN tbl_home on tbl_office.case_no = tbl_home.case_no
where tbl_office.case_no ='$a';**
I hope this will be working fine until $a(case_no) value is existed in tbl_home or else it doesn't give any rows
i am having a problem with my code. I am having the same response for my second table. While in the first one it goes to the next column.
PHP
$sql = "SELECT * from schedule s, matches m GROUP BY s.id";
$con = mysqli_connect($server_name,$mysql_user,$mysql_pass,$db_name);
$result = mysqli_query($con,$sql);
$response = array();
while($row=mysqli_fetch_array($result))
{
array_push($response, array("start"=>$row[4],"end"=>$row[5],"venue"=>$row[6], "teamone"=>$row[8], "teamtwo"=>$row[9],
"s_name"=>$row[17]));
}
echo json_encode (array("schedule_response"=>$response));
mysqli_close($con);
?>
Here is the response i am getting. As you can see the teamone, teamtwo and s_name are all the same. It does not get the value of the second column.
{"schedule_response":[
{"start":"2016-11-23 00:00:00","end":"2016-11-24 00:00:00","venue":"bbbb",
"teamone":"aaa","teamtwo":"hehe","s_name":"sssss"},
{"start":"2016-11-22 00:00:00","end":"2016-11-23 00:00:00","venue":"aaaaaaa",
"teamone":"aaa","teamtwo":"hehe","s_name":"sssss"}]}
Schedule table
Matches Table
You can define the m_id in query
$sql = "SELECT * from schedule as s, matches as m where s.m_id = m.m_id GROUP BY s.id";
To make sure you get "some answer" even if no data is properly linked, you need to us LEFT JOIN:
SELECT *
FROM schedule s
LEFT JOIN matches m ON s.m_id=m.m_id
In this context GROUP BY might be unnecessary. Depends how your data is structured
This is my first time using an inner join so i'm very confused.
I have two tables.
This is my first table called members
This is my other table called donations. The userID from the members is linked up with the userID on the donations table.
Right so what i'm trying to do is select all of the data from members and from the donations table and assiotate each Id with the donation amount. So what i'm trying to do is echo all of the names along side their donation amount if that makes sense.
This is my code at the moment
$connect - contains my config
//Connection info.
global $connect;
//inner join
$sql = "SELECT members.firstname, members.lastname
FROM members INNER JOIN donations ON members.userID = donations.userID WHERE donations.amount !='' ORDER BY members.userID ASC ";
$result = mysqli_query( $connect, $sql);
while($row = mysqli_fetch_array($result, MYSQLI_ASSOC)){
$list .= $row["firstname"];
echo $list;
}
I'm getting this error back: mysqli_fetch_array() expects parameter 1 to be mysqli_result boolean
UPDATE: Thanks for all your help, i'm running the SQL query and just getting the first and last name back.
SELECT members.firstname, members.lastname FROM members INNER JOIN donations ON members.userID = donations.userID WHERE donations.amount !='' ORDER BY members.userID ASC
I think i'm doing something wrong here !='' the donation amount is a decimal am i targeting it right?
You have typo in column name 'fisrname' => 'firstname'.
Check the query first in phpmyadmin or the other tool.
Also read about mysqli_error and later about other means of accessing the DB (like PDO, Doctrine etc.).
Replace members.id by members.userID in your query.
SELECT members.firstname, members.lastname, donations.amount
FROM members
INNER JOIN donations ON members.userID = donations.userID
WHERE donations.amount != ''
ORDER BY members.userID ASC
As for the SQL error, it's because $result is false when there's a problem with the query or no result has been found.
mysqli_fetch_array() expects parameter 1 to be mysqli_result boolean
To prevent the error, add a simple if case because your while.
if($result){
while($row = mysqli_fetch_array($result, MYSQLI_ASSOC)){
$list .= $row["firstname"];
echo $list;
}
}
$sql = "SELECT * FROM books LEFT JOIN users
ON books.readby=users.user_id WHERE users.email IS NOT NULL";
$result = mysql_query($sql);
while($row = mysql_fetch_array($result))
{
echo $row['readby']. " - read 10 books";
} //while ends
this is the code I have so far. I am trying to retrieve the number of books read by each user
and echo the results. echo the user_id and number of books he/she read
books table is like this : id - name - pages - readby
the row readby contains the user id.any ideas/suggestions? I was thinking about using count() but Im not sure how to go about doing that.
A subquery can return the count of books read per user. That is left-joined back against the main table to retrieve the other columns about each user.
Edit The GROUP BY had been omitted...
SELECT
users.*,
usersread.numread
FROM
users
/* join all user details against count of books read */
LEFT JOIN (
/* Retrieve user_id (via readby) and count from the books table */
SELECT
readby,
COUNT(*) AS numread
FROM books
GROUP BY readby
) usersread ON users.user_id = usersread.readby
In your PHP then, you can retrieve $row['numread'] after fetching the result.
// Assuming you already executed the query above and checked errors...
while($row = mysql_fetch_array($result))
{
// don't know the contents of your users table, but assuming there's a
// users.name column I used 'name' here...
echo "{$row['name']} read {$row['numread']} books.";
}
You can use count() this way:
<?php
$count = mysql_fetch_array(mysql_query("SELECT COUNT(`user_id`) FROM books LEFT JOIN users ON books.readby=users.user_id WHERE users.email IS NOT NULL GROUP BY `user_id`"));
$count = $count[0];
?>
Hope this helps! :)
I've got
a users table named "members"
a rooms table named "rooms"
a table that associates the user id to the ids of the rooms "membersRooms"
I should write a loop that prints a dropdown for each user with all the rooms, but that adds the attribute "selected" to rooms associated with the user
What's wrong with this loop?
$members = mysql_query("SELECT * FROM members ");
$rooms = mysql_query("SELECT * FROM rooms");
while($member = mysql_fetch_array($members)){
echo("<select>");
$roomsOfUser = mysql_query("SELECT roomID FROM membersRooms WHERE userID=".$member["id"]);
$cuArray = mysql_fetch_array($roomsOfUser);
while($room = mysql_fetch_array($rooms)){
if(in_array($room["id"],$cuArray,true))
echo("<option selected='selected'>".$room["roomName"]."</option>");
else
echo("<option>".$class["roomName"]."</option>");
}
echo("</select>");
}
To make this a little easier on you, you could try utilizing left and right joins on your database. This would significantly reduce your server load and still allow you to do the same functionality.
I believe, if I'm reading your database structure right, that you'ld want something along the lines of:
SELECT members.id as memberID, rooms.id as roomID, rooms.roomName, membersRooms.roomID as memberRoom
FROM members
LEFT JOIN membersRooms
ON members.id = membersRooms.userID
RIGHT JOIN rooms
ON membersRooms.roomID = rooms.id
Then in PHP you should be able to just keep track of when your memberID changes, and when it does, start a new select. If I didn't totally bungle that SQL (which I might have) then the resulting rows should look something like:
memberID | roomID | roomName | memberRoom
1 1 foo 1
1 2 bar 1
2 1 foo 1
2 2 bar 1
So on your loop iteration you would use roomID and roomName to build your select, and if RoomID matched memberRoom then you would select that row.
$rooms query while is dead
while runs once time in while
put this $rooms = mysql_query("SELECT * FROM rooms"); query line
in first while
OK, so you need information from 3 tables - members, rooms, and membersRooms. The rows from members and membersRooms line up 1:1, so we can get both of those with 1 query.
This method will minimize the number of queries needed - if you ever see yourself querying the database in a loop, ask yourself if there's a better way.
$member_query = mysql_query("SELECT * FROM members LEFT JOIN membersRooms ON (members.id = membersRooms.userID)");
$room_query = mysql_query("SELECT * FROM rooms");
$rooms = array();
while ($room = mysql_fetch_assoc($room_query))
$rooms[] = $room;
while ($member = mysql_fetch_assoc($member_query)) {
echo '<select>';
foreach($rooms as $room) {
echo "<option value='{$room['roomID']}' ";
if ($member['roomID'] == $room['id'])
echo 'selected="selected"';
echo ">{$room['roomName']}</option>";
}
echo '</select>';
}
It's worth noting that if members:rooms is a 1:many relation, you don't need to use a third table to join them - just add a roomId to members, and you're fine.