I have a query in which I want the name of a company and its employee quantity. The thing is I want to filter this result by some conditions (like employee_number > 50 etc.). My problem is that, when building the query, I don't know how to filter this result, as the condition is set over a calculated field, so when applying the condition it gives me the below
Error: `SQLSTATE[42S22]: Column not found: 1054 Unknown column 'employee_number' in 'where clause'`.
I have been trying different things, but this is what I currently have:
$query = $this->Companies->find('all')->where($conditions)->contain(['Users']);
$query
->select(['Users.name',
'Company.modified',
'employee_number' => $query->func()->count('DISTINCT(Employees.id)')])
->where('employee_number >' => 50 )
->leftJoinWith('Employees', function (\Cake\ORM\Query $query) {
return $query->where(['deleted' => 0]);
})
->group(['Employees.company_id', 'Company.id']);
First things first, you cannot refer to an aggregate in the WHERE clause, as grouping happens afterwards, hence the error, the field employee_number doesn't exist when the WHERE conditions are being applied, you have to leverage the HAVING clause instead.
Depending on the DBMS that you are using you can reference the column from the select list, MySQL for example allows that:
$query
->select([
'Users.name',
'Company.modified',
'employee_number' => $query->func()->count('DISTINCT Employees.id')
])
->leftJoinWith('Employees', function (\Cake\ORM\Query $query) {
return $query->where(['deleted' => 0]);
})
->group(['Employees.company_id', 'Company.id'])
->having(['employee_number >' => 50]);
while Postgres for example doesn't, and requires you to repeat the aggregation inside of the HAVING clause:
->having(function (
\Cake\Database\Expression\QueryExpression $exp,
\Cake\ORM\Query $query
) {
return $exp->gt($query->func()->count('DISTINCT Employees.id'), 50);
});
ps. using DISTINCT should only be necessary when you have for example multiple joins that would result in duplicate joined rows.
See also
Cookbook > Database Access & ORM > Query Builder > Aggregates - Group and Having
Related
I have a find function in my CarsSearch model that I use in a GridView widget:
$query = Cars::find();
Now I need to add an SQL SUM function to that find funtion but it doesn't work. SO I tried to show the SQL query and I got this error:
$query = Cars::find()->sum('price');
echo $query->createCommand()->sql; // Call to a member function createCommand() on integer
Method ActiveQuery::sum() executes SQL query and already returns it's result.
You don't need to do anything else with it.
echo Cars::find()->sum('price');
This will output the sum of column price for all rows in table.
If you want to add some conditions or other things you need to do that before calling sum() method.
echo Cars::find()->where(['category' => 'SUV'])->sum('price')
This will output sum of price for all cars with "SUV" as their category.
If you need to use sql SUM() function for one column in query selecting more columns you can't use ActiveQuery::sum() method. Instead you can use select() or addSelect() method to tell the query what columns you want to select.
$query = Cars::find()
->select([
'sumPrices' => 'SUM(price)',
'countCars' => 'COUNT(*)'
]);
See the documentation for more info.
I am working in yii2.
There are employee and company table employee contains company_id.
I have a filter search running properly If I use joinWith()
$query = Employee::find();
$query->joinWith(['company']);
$dataProvider = new ActiveDataProvider([
'query' => $query,
'pagination' => false,
'sort' => false,
]);
if (!($this->load($params) && $this->validate())) {
return $dataProvider;
}
//and below is the filterwhere
$query->andFilterWhere(['like', 'company.name', $this->company_id]);
But issue came when I make a query using with()
$query = Employee::find()->with(['company']);
$dataProvider = new ActiveDataProvider([
'query' => $query,
'pagination' => false,
'sort' => false,
]);
if (!($this->load($params) && $this->validate())) {
return $dataProvider;
}
//when query contain with() then this filter is not working.
$query->andFilterWhere(['like', 'company.name', $this->company_id]);
This gives error when I use with()
Database Exception – yii\db\Exception
SQLSTATE[42S22]: Column not found: 1054 Unknown column 'company.name' in 'where clause'
The SQL being executed was: SELECT COUNT(*) FROM `employee` WHERE `company`.`name` LIKE '%1%'
Here is the relation in employee with company:
public function getCompany(){
return $this->hasOne(Company::className(), ['id'=> 'company_id']);
}
Can anyone help me or guide me how could I filter data properly using with() in a query?
Thanks.
You can't swap joinWith() and with() methods when you need to filter by the column from the related table. That's because these methods does completely different things.
Methods like joinWith() and join() actually modifies the query to add the "JOIN" part to the SQL query. The with in joinWith allows you to specify the joined table by the relation definition in the model. The eager loading in joinWith is only side effect and you can even turn that off by passing false as second parameter.
When you do:
Employee::find()->joinWith(['company'])->all();
The query that is run looks like:
SELECT * FROM employee LEFT JOIN company ON (...)
On the other side the method with() doesn't modify the query itself. It only forces the eager loading of related models. In reality the second query is used for preloading the related records.
When you do:
Employee::find()->with(['company'])->all();
It actually runs queries like these:
SELECT * FROM employee;
SELECT * FROM company WHERE id IN (...company ids selected in first query...);
So when you try to do:
$query = Employee::find()
->with(['company'])
->andFilterWhere(['like', 'company.name', $this->company_id])
->all();
The generated query is
SELECT * FROM employee WHERE company.name LIKE ...
I'm using unionAll() and return the data perfectly, but I need ordernate the data and always return error because the column not exists.
$events = $this->Events
->find('available')
->where([
'Events.group_of_event_id IS NULL'
])
->select('Events.id')
->select('Events.name')
->select('Events.slug')
->select('Events.date_event_start')
->select([
'is_group' => 0
]);
$groups = $this->GroupOfEvents
->find('available')
->select('GroupOfEvents.id')
->select('GroupOfEvents.name')
->select('GroupOfEvents.slug')
->select('GroupOfEvents.date_event_start')
->select([
'is_group' => 1
]);
$limit = 10;
$page = 1;
if($this->request->query('limit'))
$limit = $this->request->query('limit');
if($this->request->query('page'))
$page = $this->request->query('page');
$offset = ($page - 1) * $limit;
$connection = ConnectionManager::get('default');
$union = $events->unionAll($groups)->epilog(
$connection
->newQuery()
->order(['date_event_start' => 'ASC'])
->limit($limit)
->offset($offset)
);
Return this error:
Error: SQLSTATE[42S22]: Column not found: 1054 Unknown column 'date_event_start' in 'order clause'
As the error states, there is no date_event_start column.
Unlinke normale SQL queries, where a non-table prefixed column would fall back to referring to one of the involved tables, similar doesn't happen for union results, with union results you have to explicity refer to the columns as they have been selected.
So you have to make sure that either the columns are selected without a table prefix, or to select and use proper aliases in the ORDER clause. In order to avoid ambiguity, I'd strongly suggest going for the latter, something like
->select(['date_event_start_alias' => 'Events.date_event_start'])
// ...
->select(['date_event_start_alias' => 'GroupOfEvents.date_event_start'])
// ...
->order(['date_event_start_alias' => 'ASC'])
It should be noted that at least with MySQL and Postgres (I'm not sure about other DBMS like SQLite or SQL Server), you actually have to set the alias only for the first SELECT. Setting it for all selects won't do any harm, so I'm including it in the example, but it's not actually necessary.
See also
Cookbook > Database Access & ORM > Query Builder > Selecting Data
I need help to convert following ql query to Linq to Sql query.
select Name, Address
from Entity
group by Name, Address
having count(distinct LinkedTo) = 1
Idea is to find all unique Name, Address pairs who only have 1 distinct LinkedTo value. Remember that there are other columns in the table as well.
I would try something like this:
Entity.GroupBy(e => new { e.Name, e.Address})
.Where(g => g.Select(e => e.LinkedTo).Distinct().Count() == 1)
.Select(g => g.Key);
You should put a breakpoint after that line and check the SQL that is generated to find what is really going to the database.
You could use:
from ent in Entities
group ent by new { ent.Name, ent.Address } into grouped
where grouped.Select(g => g.LinkedTo).Distinct().Count() == 1
select new { grouped.Key.Name, grouped.Key.Address }
The generated SQL does not use a having clause. I'm not sure LINQ can generate that.
How can I union two criteria with an OR statement?
For example I want to get Employee which has null in Birthday field OR value of this field is less than someDate. How should I rewrite this code:
var query = DetachedCriteria.For<Employee>()
.Add(SqlExpression.IsNull<Employee>(p => p.Birthday))
.Add<Employee>(emp => emp.Birthday.Value < someDate);
You need to use Disjunction()