There is probably a simple solution to this question, but if i have the function below and $events contains an unknown number of integers, how would I use the $events variable in a query like this?
function remove_events($events)
{
$sql = "delete from events where event_id in $events";
$query = $this->db->query($sql);
}
if $event is a single value then you must use
$sql = "delete from events where event_id = $events";
Or if it is an array
$sql = "delete from events where event_id in (".implode(',', $events).") ";
the following sql syntax should help you to resolve your queries .
delete FROM events WHERE event_id IN ('2','3');
In the above example (2,3) should be a codeigniter array.
hope that you have the contents in $events as like 1,2,3... . if so no problem, else if you have spaces between the numbers , use like this format.
implode(',',explode(' ',$events));
give it a try and let me know.
Let Active Record make the job:
$this->db->where_in('id', $events)->delete('events');
All values are escaped automatically producing safer queries.
Related
For the user I am testing with, their org_id column value is "student_life"
I am trying to have this function display whatever rows have the student_life column = 1. (so yes there is a column student_life which is a boolean, and then I also have a separate column named org_id and in this case has the value student_life)
I am pretty sure there is a syntax error but I cannot figure it out.
function org_id_users_table()
{
$org_id = mysql_real_escape_string($_POST["org_id"]);
$sql = $this->query("SELECT * FROM ".DBTBLE." WHERE '$org_id' = '1'");
$result = $sql['sql'];
$num_rows = $sql['num_rows'];
$this->create_table($result, $num_rows);
}
(when I replace $org_id in the "$sql=..." line with student_life the code works.
You're quoting the column name, which makes MySQL think it's a string.
$sql = $this->query("SELECT * FROM ".DBTBLE." WHERE $org_id = '1'");
Edit:
Based on your comments, I think what you actually want is this:
$sql = $this->query("SELECT * FROM ".DBTBLE." WHERE org_id = '$org_id'");
Change quotes.
$sql = $this->query("SELECT * FROM ".DBTBLE." WHERE `$org_id` = '1'");
P.S. Why shouldn't I use mysql_* functions in PHP?
Where is this coming from? $_POST["org_id"]
Do you have a form on the page posting that? Or are you just trying to get that from the database? If so, wouldn't you need another query to obtain that first?
$row_MyFirstQuery['org_id']
Otherwise if it is $_POST["org_id"], wouldn't it be single quotes not double? $_POST['org_id']
I have small PHP script which has
$query = "SELECT MAX(id) FROM `dbs`";
//query run
$row = mysql_fetch_array($result);
$val = $row[0];
Which runs fine, but I want to understand why i can't access the row with the fieldname, like if i have this
$query = "SELECT id FROM `dbs`";
i am able to use the folowing
$val = $row['id'];
but whenever i use this MAX() function, i have to change to
$val = $row[0];
to access the values
I have no clue about this. Any help would be appreciated. Thankss
You need to give it an alias:
<?php
$query = "SELECT MAX(id) AS `id` FROM `dbs`";
//query run
$row = mysql_fetch_array($result);
$val = $row['id'];
Edit:
To explain this it's probably best to show an example of a different query:
SELECT MAX(`id`) AS `maxId`, `id` FROM `dbs`
Using the above it will return as many rows are in the table, with 2 columns - id and maxId (although maxId will be the same in each row due to the nature of the function).
Without giving it an alias MYSQL doesn't know what to call it, so it won't have an associative name given to it when you return the results.
Hope that helps to explain it.
SELECT MAX(id) AS myFieldNameForMaxValue
FROM `dbs`
and then
$row = mysql_fetch_array($result);
$val = $row['myFieldNameForMaxValue'];
If you run this query on mysql commandline you'll see that the field name returned by mysql is MAX(id). Try running on phpmyadmin and you'll see the same. So if you try $row['MAX(id)'] it'll work. When using a mysql function, it gets added to the name, so use an alias, like other said here, and you're good to go: SELECT MAX(id) AS id FROM dbs. Also, never forget to use the ` chars, just in case you have some columns/tables with reserved names, likefrom`.
Thanks for previous replies
I am execution "select Name from table_name where id=1"; . i saw some tutorials for getting data from the database, they mentioned $DB = new Zend_Db_Adapter_Pdo_Mysql($params);
DB->setFetchMode(Zend_Db::FETCH_OBJ); and the result will getting through $result = $DB->fetchAssoc($sql); This $result is an array format, i want to get only name instead of getting all the data from the database. I am new to this topic. if i made any mistake pls do correct.
try this:
$result = $DB->fetchOne("SELECT name FROM table_name WHERE id=1");
This code will execute your query through doctrine getServiceLocator(). With the help of createQueryBuilder(), you can write your query directly into zend-framework2, and with setParameter, any desired condition would be set easily.
$entityManager = $this->getServiceLocator()->get('doctrine.entitymanager.orm_default');
$qb = $entityManager->createQueryBuilder();
$qb->select(array(
'TableName.columnName as columnName '
))
->from('ProjectName\Entity\TableName', 'TableName')
->where('TableName.TableId = :Info')
->setParameter('Info', $id);
$var= $qb->getQuery()->getScalarResult();
The $var variable holds the value for which, you wanted the comparison to be made with, and holds only the single values of your interest.
Im trying to pass an array that I already found by a query into another query. For example:
$first_query = "SELECT id FROM from Table WHERE user = '{$_SESSION['id'}'";
$result = mysql_query($first_query,$connection);
$ids = mysql_fetch_array($result);
This is where it gets tricky for me. I want to pass $ids into the next query.
$id_implode = implode(", ", $ids)
$second_query = "SELECT * FROM Table2 WHERE id = '{$id_implode}';
The second query doesnt seem to be working. Any help is greatly appreciated!
your second query's syntax is wrong. Once evaluated it should read
select * from Table2 where id in (1,2,3)
ditch the curly braces and change the = to in. Don't use OR - that's a dumb way of ignoring good sql functionality
EDIT: Teneff's comment makes a very good point - why are you approaching the problem in this way? If there is a relationship between the tables they can be joined and all the data you want can be retrieved in a single query. If for some reason you can't / won't join the tables you could at least try a sub-query
select * from table2 where id in (select id from table where user = $_SESSION['id']);
To use a where statement with multiple entries to match on, use in ().
$id_implode = "'".implode("', '", $ids)."'"
$second_query = "SELECT * FROM Table2 WHERE id in ({$id_implode});
I think you should use IN
$id_implode = implode(", ", $ids)
$second_query = "SELECT * FROM Table2 WHERE id IN '({$id_implode})';
This assumes that $ids is made of int of course, otherwise you have to enclose eache entry in quotes. that means
IN (6,7,8,9)//this doesn't need quotes
IN ('lemon', 'orange')//needs quotes
try to use the IN syntax:
$id_implode = implode("', '", $ids);
$second_query = "SELECT * FROM Table2 WHERE id in ('{$id_implode}');
// make empty array
$sqlArray=array();
$jsonArray=array();
// START NEED FAST WORKING ALTERNATİVES -----------------------------------------------------
// first 20 vistors
$query = "SELECT user_id FROM vistors LIMIT 20";
$result = mysql_query ($query) or die ($query);
// make vistors user query array
while ($vstr_line = mysql_fetch_array($result)){
array_push($sqlArray, $vstr_line['user_id']);
}
// implode vistors user array
$sqlArray_impl = implode("', '", $sqlArray);
// END NEED FAST WORKING ALTERNATİVES -----------------------------------------------------
// Get vistors information
$query = "SELECT id, username, picture FROM users WHERE id IN ('$sqlArray_impl')";
$qry_result = mysql_query($query) or die($query);
while ($usr_line = mysql_fetch_array($qry_result)){
array_push($jsonArray, $usr_line['id'].' - '.$usr_line['username'].' - '.$usr_line['picture']);
}
print_r($sqlArray);
echo '<br><br>';
print_r($jsonArray);
see this my functions..
i need a replacement for fast working alternatives..
function within the range specified above, to me, running faster than the alternative.
the query will return back array ?
thx for all helpers !
Can you use a JOIN or SUB SELECT to reduce the query count from 2 to 1? Might not give much of a boost but worth a shot and a cleaner implementation.
Where is the bottleneck? Most likely the db and not the php code.
Are the tables/columns properly indexed? Run EXPLAIN on both queries.
Easiest would be to include first query as subquery eliminating one turn to the DB and a lot of code:
// Get vistors information
$query = "SELECT id, username, picture FROM users WHERE id IN (SELECT user_id FROM vistors LIMIT 20)";
$qry_result = mysql_query($query) or die($query);
Unless there is more reason to have the first one seperate, but that is not visible in your code example.
If you use PDO (recommended anyway...), you can return the result array all at once using fetchAll().
For your second query, you can use string concatenation in MySQL to directly return the result you want.