for example i have two tables post table and user table, and from these i want to create a json array to pass bootstrap datatable.
My table structure. post table and user table. i want to generate an output table having post details and user details.but user name should be in drop down box.
<?php
include('config/db_i.php');
$sql_post = mysqli_query($con,"SELECT * FROM `post_tbl`");
$array = array();
$array['data'] = array();
while($res_post = mysqli_fetch_array($sql_post)){
$sql_user = mysqli_query($con,"select * from user_tbl where user_id='".$res_post['user_id']."'");
$row_user = mysqli_fetch_array($sql_user);
//what i'll code here
$array['data'][] = $res_post;
}
echo json_encode($array);
?>
You can do the concatenation at query level by joining the two tables together as such :
Select ps.post_id, ps.post_title, us.user_id, us.user_name FROM post_tbl AS ps JOIN user_tbl AS us ON ps.user_id = us.user_id
That way each row of the fetched array will have the post info and the user info which you can freely pass to bootstrap datatable.
*You can also use NATURAL JOIN
Related
Echo out the right row from an array compiled from a mysql database.
I have extracted information from a database (locations) containing three fields: id, name, city into an array called $array. I want to loop through another database (events) in which the id's from the first database (locations) are stored in a field. When looped I want to display the corresponding name and city from the locations database.
Is this possible without having to fetch information every loop?
This is my first try
$query = "Select id, name, city FROM locations WHERE typ = '1'";
$result = mysqli_query($conn, $query);
$row = array();
while ($row = mysqli_fetch_assoc($result)) {
$array[] = $row;
}
And then I thought I could specify the key myself like this:
$query = "Select id, name, city FROM locations WHERE typ = '1'";
$result = mysqli_query($conn, $query);
$row = array();
while ($row = mysqli_fetch_assoc($result)) {
$array[$row['id']] = $row;
}
But I couldn't figure out how to echo the right row.
You can join both tables in a single query, using something like this:
Select locations.id, locations.name, locations.city, events.name
FROM locations
JOIN events ON locations.id = events.id
WHERE locations.typ = '1'
The events.id on the JOIN statement is assuming that this is the column name of the id in the events table. I also made the assumption that these are the two fields that will match between the two tables. Adjust accordingly if your matching criteria is different.
The SELECT statement was modified to pull columns from both tables. Add whichever fields are relevant to your needs.
Hi there I have 2 tables
|id|musicname|url|image|type
and the second table
|id|user|songslist|
inside songsids theres an array like this
1,3,5,6,8 etc ...
What Im aiming to do is select * from table1 and echo out the table1 as in an array but instead of tables two array , the actual row of table1.
So basically To take out each row that contains the id in songslist and put them all into a php array.
I have learned a lot about PHP arrays , but I'm not that good with mysql , Any Idea of how can I do that ?
EDIT
$selectmusiclist = mysql_query("SELECT * FROM music");
$songslist = array();
while ($songs = mysql_fetch_assoc($selectmusiclist)){
$songslist[] = $songs;
}
and then table 2 select:
$username="user1";
$selectuser = mysql_query("SELECT * FROM usersmusic where user=$username");
$user = mysql_fetch_assoc($selectuser);
$songslist = $user['songslist'];
NOW I need to tell the array $songslist[] to output only the songs with id $songslist contained ids
I think running a join like this will give you the results you are after.
SELECT * FROM usersmusic as um
join music as m
on um.songslist = m.id
where user = '$username'
If $username is not a static value make sure you escape it; don't want to get SQL injected in the future.
Also note the mysql_ driver is now deprecated you should consider updating to mysqli or PDO.
I have a table named users and has a user_id, and a table named groups and has a group_id and also have user_id that is a foreign key reference from users's user_id.The situation is here: if the user joined a group, his/her user_id is inserted into table groups. So if the user joined two different groups, the column 'user_id' in table 'groups' will insert two or more same user_id's. Well, I just want to bring the user_id once, either he/she joined two or more groups..
I have no idea how to loop it properly without getting user_id that is the same.... I just want it to loop once...
$query_groups = mysql_query("SELECT * FROM groups");
while ($rows_g = mysql_fetch_assoc($query_groups)) {
$g_user_id = $rows_g['user_id'];
$query_users = mysql_query("SELECT * FROM users WHERE user_id='$g_user_id'");
while ($rows_u = mysql_fetch_assoc($query_users)) {
echo $rows_u['user_id'];
}
}
change your code as follows:
$query_groups = mysql_query("SELECT user_id FROM groups LEFT JOIN users ON users.user_id = groups.user_id GROUP BY groups.user_id");
while($rows = mysql_fetch_assoc($query_groups))
{
echo $rows['user_id'];
}
You are using $rows_g but the variable is namend $rows in the first while loop.
Wrong:
$g_user_id = $rows_g['user_id'];
Correct:
$g_user_id = $rows['user_id'];
But try to use joining tables, because this is an inefficient way to get the wanted data.
In your case you should use LEFT JOIN.
Im having difficulties trying to figure out an elegant solution to sorting the results of a mysql query based on a delimited string. Ill explain in more detail below
I am creating a database of contacts where individual users can add/remove people from a list. When the user adds a new contact I append the added contact id to a delimited string and store that data in a database column associated with that user (named contacts):
$userID = ?? //YOUR ID
$contactID = ?? //WHATEVER THE ADDED USER ID IS
$confirm = 0 //has the user been confirmed
$sql = "SELECT contacts FROM user WHERE id = '$userID'";
$query = mysql_query($sql);
$row = mysql_fetch_array($query);
$contact = $row['contacts'];
$contact .= '|'.$contactID.':'.$confirm;
$update = mysql_query("UPDATE user SET contacts = '$contact' WHERE id = '$userID'");
//contact column data might be: |10:0|18:0|36:0|5:0
When the user searches their contacts I grab the data from the contacts column, explode/split the string and return the individual users names:
$userID = ?? //YOUR ID
$sql = "SELECT contacts FROM user WHERE id = '$userID'";
$query = mysql_query($sql);
$row = mysql_fetch_array($query);
$contacts = explode("|", $row['contacts']);
foreach($contacts as $item)
{
list($contactID,$confirm) = split(":", $item);
$sql = "SELECT name FROM ".user." WHERE id = '$contactID'";
$query = mysql_query($sql);
$row = mysql_fetch_array($query);
echo($row['name'].'<BR>');
}
This indeed does return all the names, but it returns them in the order of the delimited string. I cant seem to find an elegant way to sort by name alphabetically.
Should I not store the contacts list in a delimited string? How would you solve this?
You're right, you should not store the contacts in a string. Instead use another table which contains the user information. The new table should look something like the following:
Table: user_contacts
| user_id | contact_id | confirm |
-------------------------------------------
| your data here... |
Then when you need your contact list you can simply perform another query:
SELECT * FROM `user_contacts`
JOIN `users` ON `users`.`id` = `user_contatcs`.`user_id`
WHERE `users`.`id` = $id
ORDER BY `users`.`name`;
Or however you need to order it.
There are two obvious approaches:
Sort the results once you've fetched them
Fetch them all in one query and have the DB sort them
For #1, use usort():
$rows = array();
foreach ($contacts as $item){
list($contactID,$confirm) = split(":", $item);
$query = mysql_query("SELECT name FROM user WHERE id = '$contactID'");
$rows[] = mysql_fetch_array($query);
}
usort($rows, 'sort_by_name');
function sort_by_name($a, $b){
return strcmp($a['name'], $b['name']);
}
foreach ($rows as $row){
echo($row['name'].'<BR>');
}
For #2, build a list of IDs and use IN:
$ids = array();
foreach ($contacts as $item){
list($contactID,$confirm) = split(":", $item);
$ids[] = $contactID;
}
$ids = implode(',', $ids);
$query = mysql_query("SELECT name FROM user WHERE id IN ($ids) ORDER BY name ASC");
while ($row = mysql_fetch_array($query)){
echo($row['name'].'<BR>');
}
If you're using a relational database, then what you want is a separate table that stores person-contact relationships. Then you would modify your sql query to select based on a join across two tables
SELECT * FROM person, contact
JOIN contact ON person.id = contact.personid
JOIN person ON contact.contactid = person.id
WHERE person.id = $id
ORDER BY person.lastname
(That code is probably not quite correct.)
If you're using a no-sql type implementation, the way you're doing it is fine, except that you will either have to programmatically sort after the fact, or sort-on-insert. Sort on insert means you'd have to query the current list of contacts on inserting one, then sort through to find the right position and insert the id into the delimited string. Then save that back to the db. The downside to this is you'll only be able to sort one way.
Generally, people use relational databases and 'normalize' them as described above.
i have retrieved mysql data from one table in json using the following script
$table_first = 'abc';
$query = "SELECT * FROM $table_first";
$resouter = mysql_query($query, $conn);
$set = array();
$total_records = mysql_numrows($resouter);
if($total_records >= 1){
while ($link = mysql_fetch_array($resouter, MYSQL_ASSOC)){
$set[] = $link;
}
}
echo json_encode($set);
how can i retrieved data from two other tables in which there is a foreign key of this table in both of those tables. OR simply how can i retrieved data from 3 mysql tables in php.
I believe the best way to go here is using a JOIN or just something like this:
$sql = "SELECT
tabl1.*, table2.*, tabl3.* FROM table1, table2, table3
WHERE
table1.fk1 = table2.id AND
table1.fk2 = table2.id";
//Do the whole selection process...
If you make the queries separately, you'll be forcing 3 queries onto your database and will end in a performance hit that you dont need. So, the idea is load all the data from the DB using joins or similar that and then encode the results. Is faster and you'll leave the merging work to MySQL
Hope I can help
You can get all data firstly.
Then merge the data array.
Finally use json_encode to change the data format.
There is a foreign key of this table in both so you can use "join" to retrieve values from other tables.
Suppose that there are two tables as State(st_id,st_name) and City(ct_id,ct_name,state_id). Now, primary key are st_id & ct_id respectively of tables State & City.
Connection between this two table can be establish by joining State.st_id and City.state_id.
Now, coming to your problem to retrieve data from two table State & City, we can make sql query like following,
$sql="select s.*, c.* from State s, City c
where s.st_id=c.state_id ";
Using above query you can fetch data from database and convert into json format and can send it to android system. here is a good article http://blog.sptechnolab.com/2011/02/10/android/android-connecting-to-mysql-using-php/. i hope you like it.
I believe your code roughly will look like this:
$query = "SELECT
A.column1 AS First_1
A.column2 AS First_2
B.column2 AS Second
C.column3 AS Third
FROM table1 A, table2 B, table3 C
WHERE
A.fk1 = B.id AND
B.fk2 = C.id";
where a column is a relevant record you want to show. Meanwhile,
AS will act as a key name in JSON.