I'm very new to zend (1.12)..so please excuse my very basic question:
I want to fetch only one row from a database. Thatfore I want to use the fetchRow(..) function like this
$row = $db->fetchRow($db->select()->where("col1 = '".val1."' AND col2='".val2."'"));
The problem is, that there may be many rows that fit to the where-clause and I only want to get the one with the highest id. How can I do this?
The fetchRow() method returs only one row. If you want to choose row with the highest ID meeting other conditions, invoke it like this:
$select = $db->select()
->where('col1 = ?', $val1)
->where('col2 = ?', $val2)
->order('id DESC');
$row = $db->fetchRow($select);
Also, remember to pass values to SQL query in the way as in above code (to avoid SQL injection attack risk).
Related
I have a question on how I can extract data from Moodle based on a parameter thats "greater than" or "less than" a given value.
For instance, I'd like to do something like:
**$record = $DB->get_record_sql('SELECT * FROM {question_attempts} WHERE questionid > ?', array(1));**
How can I achieve this, cause each time that I try this, I get a single record in return, instead of all the rows that meet this certain criteria.
Also, how can I get a query like this to work perfectly?
**$sql = ('SELECT * FROM {question_attempts} qa join {question_attempt_steps} qas on qas.questionattemptid = qa.id');**
In the end, I want to get all the quiz question marks for each user on the system, in each quiz.
Use $DB->get_records_sql() instead of $DB->get_record_sql, if you want more than one record to be returned.
Thanks Davo for the response back then (2016, wow!). I did manage to learn this over time.
Well, here is an example of a proper query for getting results from Moodle DB, using the > or < operators:
$quizid = 100; // just an example param here
$cutoffmark = 40 // anyone above 40% gets a Moodle badge!!
$sql = "SELECT q.name, qg.userid, qg.grade FROM {quiz} q JOIN {quiz_grades} qg ON qg.quiz = q.id WHERE q.id = ? AND qg.grade > ?";
$records = $DB->get_records_sql($sql, [$quizid, $cutoffmark]);
The query will return a record of quiz results with all student IDs and grades, who have a grade of over 40.
When you retrieve data through a MySQLi statement such as the following:
$sqls = "SELECT * FROM course WHERE course='$product_id_array' OR course='Both' ORDER BY ...";
$sqlsresults = mysqli_query($db_conx,$sqls);
while($row = mysqli_fetch_assoc($sqlsresults)) {
$selectedContent = $row["content"];
$selectedTitle = $row["title"];
}
Is there a way to output the match for 'both' first? Would this be as simple as re-arranging the order of the WHERE portion of the statement?
Your ORDER BY explicitly sorts only by id. There is no way around this in the WHERE part of your query. To change how results are ordered, use ORDER BY.
SELECT *
FROM course
WHERE course=...
OR course='Both'
ORDER BY CASE course WHEN 'Both' THEN 0 ELSE 1 END ASC, id DESC
Unrelated note: if $product_id_array contains untrusted user input, the user can put things like '; DELETE FROM course; -- in there. Read up on parameterized queries to learn how to prevent that.
This might be a very simple thing. Check out the normal sql query below
(select * from shopping order by shopping_id desc limit 5) order by RAND()
This query runs successfully in mysql - not sure if this is the right way of doing it - but it works. It gets the last 5 ids from shopping table and randomly orders them everytime
I want to achieve this in Zend. I'm not sure how to execute the first part and then apply the RAND clause to the results - what I have below does not do that.
$select = $this->select()
->from(array('sh'=>'shopping'))
->order('shopping_id desc')
->limit(5)
->order('RAND()');
Why not take a slightly different approach which will acheive the same results. If you drop the subselect and the order by RAND() you can get the rows very quickly from the database, then when you are working with the rows, you could always randomize them.
$select = $this->select()
->from(array('sh'=>'shopping'))
->order('shopping_id desc')
->limit(5)
$rows = $this->fetchAll($select);
// take it from a rowset object, convert to an array:
$rowArray = array();
foreach ($rows as $row) $rowArray[] = $row;
shuffle($rowArray);
The Zend_Db_Expr class lets you do that. You create a new instance of the Zend_Db_Expr class and using its constructor you pass in the expression as a string: "RANDOM()".
$select = $this->select()
->from(array('sh'=>'shopping'))
->order('shopping_id desc')
->limit(5)
->order(new Zend_Db_Expr('RANDOM()'));
It seems like there's a few different ways to join two tables using the Zend Framework, but I've never done it before so I don't know which is the best way to do it.
This is what I'm trying to do...
I have 3 tables in my database:
users
( id , name )
groups
( id , name )
group_members
( id , group_id , user_id )
I'm trying to look up the groups that a user belongs to and display that to the user. This SQL statement pretty much does the job (though there may be a better way to write it). It only returns the columns I'm concerned with which are the group's id and title.
SELECT groups.id, groups.title
FROM group_members
INNER JOIN groups
ON groups.id = group_members.group_id
WHERE user_id = $userId
How can I do this with the Zend Framework?
Finally figured out how to do it. If you've got a better way, please let me know.
$db = Zend_Db_Table::getDefaultAdapter(); //set in my config file
$select = new Zend_Db_Select($db);
$select->from('groups', array('id', 'title')) //the array specifies which columns I want returned in my result set
->joinInner(
'group_members',
'groups.id = group_members.group_id',
array()) //by specifying an empty array, I am saying that I don't care about the columns from this table
->where('user_id = ?', $userId);
$resultSet = $db->fetchAll($select);
This will return a table with only the id and title columns. The empty array() was the key to removing the columns I didn't care about. I could then do something with the result set.
foreach ($resultSet as $row) {
//do something with $row->id or $row->title
}
No need to using Join,we can use Zend_Db_Table instead for the reason about the MVC pattern. I got this idea form here,#10 by Filip.(maybe they call this "Table Data Gateway"?)
I have built a multistep form using CCK, however I have a couple of issues outstanding but, not sure if CCK can help.
In one step of the form I have 2 select boxes, the first is auto populated from the vocabulary table with the following code and all woks well.
$category_options = array();
$cat_res = db_query('select vid, name from vocabulary WHERE vid > 1 ORDER BY name ASC');
while ($cat_options = db_fetch_object($cat_res)) {
$category_options[$cat_options->vid] = $cat_options->name;
}
return $category_options;
What I would like to do is, when a user selects one item from the vocablulary list it auto populates another select box with terms from the term_data table. I have 2 issues;
1) I have added the following code to the second select list, just to make sure it works (IT DOESN'T). There a multiple terms associated with each vocabulary, but the second sql statemant only returns one result when it should return several, (SO SOMETHING WRONG HERE). For example in the term_date table there are 6 terms with the vid of 3, but I only get one added to select list.
$term_options = array();
$term_res = db_query('select vid, name from term_data WHERE vid = 3 ORDER BY name ASC'); while ($options = db_fetch_object($term_res)) {
$term_options[$options->vid] = $options->name;
}
return $term_options;
2) Can I add an onChange to the first select list to call a function to auto populate second list using CCK, or do I have to lean towards doing my entire form using the FORM API.
Any help or thoughts would be very much appreciated.
It seems to be a mistake in the query that gets terms. I tried to correct:
$term_res = db_query('select tid, name from term_data WHERE vid = 3 ORDER BY name ASC');
while ($options = db_fetch_object($term_res)) {
$term_options[$options->tid] = $options->name;
}
In your code you selected vid that is actually equal for all terms. Then you added terms names to $term_options array under the same key => so you got only 1 element.
Considering the second question: I would send the whole data structure (all vocabularies and their terms) as json to the client (insert a js script to the page from your drupal code) and implement the desired functionality with jquery.