i know i can define relationships through _referenceMap, i know that i con join selects trough
$db->select()
But what i need is to fetch rowset in model extending Zend_Db_Table_Abstract and then order it by value of referenced column from another table.
Is there some workaround to do that?
edit:
heres is the example:
first table:
table bugs columns id, bugname, authorid
second table:
table authors columns id, authorname
I have a model Model_Bugs extends Zend_Db_Table_Abstract
I want to make something like this:
$model->fetchAll($model->select()->order('authorname ASC'))
This means, that i need to join tables and sort by a column, which is not in the model table.
thanks for help
Jan
I would add a method in Model_Bugs like so:
public function fetchBugsByAuthorname() {
$bugTable = $this;
$bugTableName = $this->info('name');
$authorsTable = new Model_Authors();
$authorsTableName = $authorsTable->info('name');
$select = $bugTable->select()
->setIntegrityCheck(false)
->from($bugTable, array('id', 'bugname', 'authorid'))
->join($authorsTableName,
"$bugTableName.authorid = $authorsTableName.id",
array("authorname"))
->order("$authorsTableName.authorname asc");
$result = $bugTable->fetchAll($select);
return $result;
}
But to do this you have to turn off ZF's table integrity checking (setIntegrityCheck(false) above), which means you won't be able to directly call save() on the resulting rows. But if it's for a read-only purpose, it will work.
If you needed to save rowsets back to the database, you may have to first select the author ID's from Model_Authors in the order you want them, and then re-order your Model_Bugs query accordingly. It's messier but it can work.
Related
I am learning how to do simple queries using the Yii2 framework. I use PostgreSQL.
I am trying to join two tables and get the data from both tables with a where condition.
The tables are called Admins and Persons.
The join use field called idadm.
The condition is idadm = 33. This works great but the result has data only from the Admins table and I need data from the other table.
Here is my example:
$query = \app\models\Admins::find()
->select('*')
->leftJoin('persons', 'persons.idadm = admins.idadm')
->where(['admins.idadm' => 33])
->with('persons')
->all();
I am following the Yii2 official guide: http://www.yiiframework.com/doc-2.0/guide-db-active-record.html
Update: Here I show the updated code that doesn't solve de problem:
You need to write all column name in select().
$query = \app\models\Admins::find()
->select('admin.*,persons.*') // make sure same column name not there in both table
->leftJoin('persons', 'persons.idadm = admins.idadm')
->where(['admins.idadm' => 33])
->with('persons')
->all();
And also you need to define person table attributes in Admin model.
Second way is get records as array,so you dont need to define attributes in Admin model.
$query = \app\models\Admins::find()
->select('admin.*,persons.*') // make sure same column name not there in both table
->leftJoin('persons', 'persons.idadm = admins.idadm')
->where(['admins.idadm' => 33])
->with('persons')
->asArray()
->all();
Ensure that active record has required relations, e.g. something like follows:
class Admins extends \yii\db\ActiveRecord {
public function table() {
return "admins";
}
public function getPersons()
{
return $this->hasMany(Person::className(), ['idadm' => 'idadm']);
}
}
class Person extends \yii\db\ActiveRecord {
public function table() {
return "persons";
}
}
Then use joinWith to build query:
$query = Admins::find()
->joinWith('persons')
->limit(1);
$result = $query->createCommand()->getSql();
echo $result;
Here is produced query:
SELECT `admins`.* FROM `admins`
LEFT JOIN `person` ON `admins`.`idadm` = `person`.`idadm` LIMIT 1
Im trying to select only specific attributes on the many-to-many relation users, just like in one-to-one. But using select() on belongsToMany() seem to be ignored and i'm still getting all the User attributes.
class Computer extends Eloquent {
public function users() {
return $this->belongsToMany("User")->select("email");
}
public function admin() {
return $this->hasOne("User")->select("email");
}
}
Computer::with("users")->get();
Is there a way of filtering only specified columns from related entity with belongsToMany()?
Yes, you actually can.
Computer::with("users")->get(array('column_name1','column_name2',...));
Be careful though if you have the same column name for both tables linked by your pivot table. In this case, you need to specify the table name in dot notation, tableName.columnName. For example if both users and computer has a column name id, you need to do :
Computer::with("users")->get(array('users.id','column_name2',...));
According to Taylor Otwell it is not currently possible: https://github.com/laravel/laravel/issues/2679
I have tried to use a lists('user.email') at the end of the query but I can't make it work.
Computer::with(["users" => function($query){
$query->select('column1','column2','...');
}])->get();
I have a method:
public List<Timetable> getTimetableTableForRegion(String id) {
List<Timetable> timetables;
TypedQuery<Timetable> query = em_read.createQuery("SELECT ..stuff.. where R.id = :id", Timetable.class).setParameter("id", Long.parseLong(id));
timetables = query.getResultList();
return timetables;
}
which returns this:
so, what am I missing in order to return a list of Timetable's?
ok, so, ..stuff.. part of my JPQL contained an inner join to other table. Even through in SELECT there were selected fields just from one table, which was used as type - Timetable, Eclipslink was unable to determine if this fields are part of that entity and instead of returning list of defined entity returned list of Object[].
So in conclusion: Use #OneToMany/#ManyToOne mappings (or flat table design) and query just for ONE table in your JPQL to be able to typize returned entities.
Not sure it might be something is looking for, but I had similar problem and converted Vector to ArrayList like this:
final ArrayList<YourClazz> results = new ArrayList<YourClazz>();;
for ( YourClazzkey : (Vector<YourClazz>) query.getResultList() )
{
results.add(key);
}
i have faced the same problem. and my entity has no one to one or one to many relationship. then also jpql was giving me queryresult as vector of objects. i changed my solution to query to criteria builder. and that worked for me.
code snippet is as below:
CriteriaBuilder builder = this.entityManager.getCriteriaBuilder();
CriteriaQuery<Timetable> criteria = builder.createQuery(Timetable.class);
Root<Enumeration> root = criteria.from(Timetable.class);
criteria.where(builder.equal(root.get("id"), id));
List<Timetable> topics = this.entityManager.createQuery(criteria) .getResultList();
return topics;
Im trying to call a stored procedure using Entity framework.
If I go direcly to the web api method it works fine, but when calling it from breeze it causes an exception on the metadata method.
The error is :
"Could not find the CLR type for...".
Anyone know how to fix this?
I had the very same issue, but thank God I figured out a solution. Instead of using a stored procedure, you should use a view, as Breeze recognizes views as DbSet<T>, just like tables. Say you have a SQL server table that contains two tables Customers and Orders.
Customers (**CustomerId**, FirstName, LastName)
Orders (OrderId, #CustomerId, OrderDate, OrderTotal)
Now, say you want a query that returns orders by CustomerId. Usually, you would do that in a stored procedure, but as I said, you need to use a view instead. So the query will look like this in the view.
Select o.OrderId, c.CustomerId, o.OrderDate, o.OrderTotal
from dbo.Orders o inner join dbo.Customers c on c.CustomerId = o.CustomerId
Notice there is no filtering (where ...). So:
i. Create a [general] view that includes the filtering key(s) and name it, say, OrdersByCustomers
ii. Add the OrdersByCustomers view to the entity model in your VS project
iii. Add the entity to the Breeze controller, as such:
public IQueryable<OrdersByCustomers> OrdersByCustomerId(int id)
{
return _contextProvider.Context.OrdersByCustomers
.Where(r => r.CustomerId == id);
}
Notice the .Where(r => r.CustomerId == id) filter. We could do it in the data service file, but because we want the user to see only his personal data, we need to filter from the server so it only returns his data.
iv. Now, that the entity is set in the controller, you may invoke it in the data service file, as such:
var getOrdersByCustomerId = function(orderObservable, id)
{
var query = breeze.EntityQuery.from('OrdersByCustomerId')
.WithParameters({ CustomerId: id });
return manager.executeQuery(query)
.then(function(data) {
if (orderObservable) orderObservable(data.results);
}
.fail(function(e) {
logError('Retrieve Data Failed');
}
}
v. You probably know what to do next from here.
Hope it helps.
I have a statement:
var items = from e in db.Elements
join a in db.LookUp
on e.ID equals a.ElementID
where e.Something == something
select new Element
{
ID = e.ID,
LookUpID = a.ID
// some other data get populated here as well
};
As you can see, all I need is a collection of Element objects with data from both tables - Elements and LookUp. This works fine. But then I need to know the number of elements selected:
int count = items.Count();
... this call throws System.NotSupportedException:
"The entity or complex type 'Database.Element' cannot be constructed in a LINQ to Entities query."
How am I supposed to select values from multiple tables into one object in Entity Framework? Thanks for any help!
You are not allowed to create an Entity class in your projection, you have to either project to a new class or an anonymous type
select new
{
ID = e.ID,
LookUpID = a.ID
// some other data get populated here as well
};
Your code doesn't work at all. The part you think worked has never been executed. The first time you executed it was when you called Count.
As exception says you cannot construct mapped entity in projection. Projection can be made only to anonymous or non mapped types. Also it is not clear why you even need this. If your class is correctly mapped you should simply call:
var items = from e in db.Elements
where e.Something == something
select e;
If LookupID is mapped property of your Element class it will be filled. If it is not mapped property you will not be able to load it with single query to Element.