I have a "big" query with 10 joins, and finally a single where condition.
I also have about 6 arrays, each being filled with a select statement from said query.
$first_array = $query->select()->first();
In two of the arrays, I get the data using get() instead of first(). The issue is, the get() method is only returning one row, when I know for a fact that there are two that match the condition. I used the toSql() method to see the resulting query, only to find there is a limit 1 being appended to the query that I did not place. Is the limit being appended because I'm using first() in some of the queries, which is limiting my results to one row? I've tried executing the query in my database manager and after removing the limit 1 from the query it does return the two rows I'm expecting.
The issue was, if you did this like I did:
$array1 = $query->select()->first();
$array2 = $query->select()->first();
$array3 = $query->select()->first();
$array4 = $query->select()->first();
$array5 = $query->select()->get();
The first() method calls set the limit 1, and using get() afterwards does not remove the limit.
If you use get() first then first() like so:
$array5 = $query->select()->get();
$array1 = $query->select()->first();
$array2 = $query->select()->first();
$array3 = $query->select()->first();
$array4 = $query->select()->first();
then the issue does not occur.
Replace first() with get() is the answer. first() is for retrieving a single model: https://laravel.com/docs/8.x/eloquent#retrieving-single-models where get() returns you the collection of results: https://laravel.com/docs/8.x/eloquent#collections
Related
When I execute a SQL query from Java and store the boolean returned, the query always returns true which shouldn't be the case at all. So I emptied the table and fired the query again, and yet it returns true for the emptied table. I have attached a picture of the table. I want the query to return true or false, so I can store it in Java. Can someone please specify an alternate code for this, please?
This is my code on java for the query.
boolean avail = st.execute("SELECT EXISTS(SELECT * from sales WHERE product='"+n+"' AND ord_date='"+sqlDate+"');");
And this is my code for result set
Statement st = con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
This is the table, name of the table is 'sales'
I'm new to MySQL, a more specific approach is appreciated.
Statement.execute will return true regardless of what the query returns. You are still supposed to retrieve the actual result of the query.
Returns
true if the first result is a ResultSet object; false if it is an update count or there are no results
As you execute an EXISTS statement, there will always be a result (true or false). The actual value still has to be retrieved:
You must then use the methods getResultSet or getUpdateCount to retrieve the result, and getMoreResults to move to any subsequent result(s).
For reference: https://docs.oracle.com/javase/8/docs/api/java/sql/Statement.html#execute-java.lang.String-String
Also note that you are directly embedding strings into your query, this will leave you vulnerable to SQL injections. Please read: How can prepared statements protect from SQL injection attacks?. Recommended reading: Introduction to JDBC
The return value of Statement.execute() signals whether the query produces a result set (true) or - possibly - an update count (false). The query you execute is a select which will always produce a result set (even if empty). In other words, it will always return true for a select.
If you want to get the result of your query, then the recommend approach is to use executeQuery. However, you are also concatenating values into your query string, which is a bad idea because it leave you vulnerable to SQL injection. The recommended approach is to switch to prepared statements:
try (PreparedStatement pstmt = con.prepareStatement(
"SELECT EXISTS(SELECT * from sales WHERE product = ? AND ord_date = ?)")) {
pstmt.setString(1, n);
pstmt.setDate(2, sqlDate);
try (ResultSet rs = st.executeQuery() {
boolean avail = rs.next() && rs.getBoolean(1);
// use avail...
}
}
I've been stuck on a GORM issue for about a full day now. I need to be able to filter a messages table on any of 4 things: sender, recipient, keyword, and date range. It also has to paginate. Filtering by sender and recipient is working, and so is pagination. So far this is the query that I have come up with, but it does not seem to work for date ranges or keywords.
Here is how I am selecting from MySQL
db.Preload("Thread").Where(query).Scopes(Paginate(r)).Find(&threadMessages)
I am creating the query like this:
var query map[string]interface{}
Then based on which parameters I am passed, I update the query like this by adding new key values to the map:
query = map[string]interface{}{"user_id": sender, "recipient_id": recipient}
For dates it does not seem to work if I try something like this:
query = map[string]interface{}{"created_at > ?": fromDate}
And for a LIKE condition is also does not seem to work:
query = map[string]interface{}{"contents LIKE ?": keyword}
The reason I chose this approach is that I could not seem to get optional inputs to work in .Where since it takes a string with positional parameters and null positional parameters seem to cause MySQL to return an empty array. Has anyone else dealt with a complicated GORM issue like this? Any help is appreciated at this point.
Passing the map[string]interface{} into Where() only appears to work for Equals operations, or IN operations (if a slice is provided as the value instead).
One way to achieve what you want, is to construct a slice of clause.Expression, and append clauses to the slice when you need to. Then, you can simply pass in all of the clauses (using the ... operator to pass in the whole slice) into db.Clauses().
clauses := make([]clause.Expression, 0)
if mustFilterCreatedAt {
clauses = append(clauses, clause.Gt{Column: "created_at", fromDate})
}
if mustFilterContents {
clauses = append(clauses, clause.Like{Column: "contents", Value: keyword})
}
db.Preload("Thread").Clauses(clauses...).Scopes(Paginate(r)).Find(&threadMessages)
Note: If you're trying to search for content that contains keyword, then you should concatenate the wildcard % onto the ends of keyword, otherwise LIKE behaves essentially the same as =:
clause.Like{Column: "contents", Value: "%" + keyword + "%"}
My final solution to this was to create dynamic Where clauses based on which query params were sent from the client like this:
fields := []string{""}
values := []interface{}{}
If, for example, there is a keyword param:
fields = []string{"thread_messages.contents LIKE ?"}
values = []interface{}{"%" + keyword + "%"}
And to use the dynamic clauses in the below query:
db.Preload("Thread", "agency_id = ?", agencyID).Preload("Thread.ThreadUsers", "agency_id = ?", agencyID).Joins("JOIN threads on thread_messages.thread_id = threads.id").Where("threads.agency_id = ?", agencyID).Where(strings.Join(fields, " AND "), values...).Scopes(PaginateMessages(r)).Find(&threadMessages)
I got values stored in my database column field as value1,value2,value3,value4, so a simple_array column.
So i'm using Doctrine to make a search using this:
$searchQuery = $this->getDoctrine()
->getRepository('AppBundle:Ads')
->createQueryBuilder('p')
->andWhere("p.vals <= :value2")
->setParameter('value2', $request->query->get('value2'));
->orderBy("p.creationtime", 'DESC');
So expecting value2 is in the 2nd position of a simple array like value1,value2,value3, how can i ask QueryBuilder to select the second value in the string?
I think this query try to get all the values in p.vals, results are not right, shound select just one.
How can I select eg. the 2nd value in p.vals?
I believe you cannot access nth item of an array column using pure Mysql since the data is serialized, in order to do it I'd create a simple function
public function getItemFromArray(array $array, $index)
{
return isset($array[$index]) ? $array[$index] : null;
}
And if you want to find item with condition use
array_filter()
Im using this direct query method in cakephp to get a count (against the norms of MVC).
$count = $this->History->query("SELECT count(id) AS x FROM ratings WHERE id='3' AND employee='28'");
But it turns out that, i need to use $count[0][0]['x'] to get the value.
Why isnt it available at $count['x']?
in your case it will return it in a general way: 0 = iterate over all models, and again 0 since you dont have a specific model name). your result will always be in $count[0][0]['fieldname'] then.
it is highly recommended to always use the wrapper methods if possible.
why are you not using the cakephp database wrapper methods as documented?
$count = $this->History->find('count', array('conditions'=>array('id'=>3, 'employee'=>28));
?
it would result in the expected output x
Simply, its because the function
$this->History->query(....);
does not return a single dimensional array. I will suggest you to create a helper function, which extracts the single dimensional array and return it.
function single_query($query) {
$result = $this->History->query($query);
return $result[0][0];
}
then use it
$count = $this->single_query("SELECT count(id) AS x FROM ratings WHERE id='3' AND employee='28'");
I have a Doctrine query;
$q = Doctrine_Query::create()->select('s.monthly_volume')
->from('SearchVolume s')
->innerJoin('s.Keywords k')
->where('k.group_id = ?',array($group_id));
I just want it to return the monthly_volume value in the result array. It currently returns monthly_volume and id, I don't want it to return the id in result.
Doctrine automatically adds the primary key field to the results in almost every type of hydration mode.
In a case like this where you want a simple array and only have a single field being selected, the answer is the Single Scalar Hydration mode. Use it like this:
$q = Doctrine_Query::create()->select('s.monthly_volume')
->from('SearchVolume s')
->innerJoin('s.Keywords k')
->where('k.group_id = ?');
$monthly_volumes = $q->execute(array($group_id), Doctrine_Core::HYDRATE_SINGLE_SCALAR);
You should find that $monthly_volumes is a simple one-dimensional array containing only the value(s) you wanted.