How to create a select where count is not zero in MySQL - mysql

Here's what I'm trying to do. I'm trying to select from a forum views table all of the user_ids where there are 5 or more records. That's fairly easy (this is Zend):
$objCountSelect = $db->select()
->from(array('v' =>'tbl_forum_views'), 'COUNT(*) AS count')
->where('u.id = v.user_id')
->having('COUNT(user_id) >= ?', 5)
;
But I need to somehow connect this to my users table. I don't want to return a result if the count is greater than 5. I tried this:
$objSelect = $db->select()
->from(array('u' => 'tbl_users'), array(
'id as u_id',
'count' => new Zend_Db_Expr('(' . $objCountSelect . ')'),
))
;
But that returns a record for every user, leaving blank the count if it's less than or equal to 5. How do I exclude the rows where the count is less than or equal to 5?

I figured it out, but wanted to post the answer in case someone else had the same issue. I added:
->having('count > 0')
to the second select and now it works.

Related

Iterating over records in one table and adding them to another with calculations

I'm currently using PHP and MySQL to retrieve a set of 100,000 records in a table, then iterate over each of those records to do some calculations and then insert the result into another table. I'm wondering if I'd be able to do this in pure SQL and make the query run faster.
Here's what I"m currently using:
$stmt= $pdo->query("
SELECT Well_Permit_Num
, Gas_Quantity
, Gas_Production_Days
FROM DEP_OG_Production_Import
ORDER
BY id ASC
");
foreach ($stmt as $row) {
$data = array('well_id' => $row['Well_Permit_Num'],
'gas_quantity' => $row['Gas_Quantity'],
'gas_days' => $row['Gas_Production_Days'],
'gas_average' => ($row['Gas_Production_Days']);
$updateTot = $pdo->prepare("INSERT INTO DEP_OG_TOTALS
(Well_Permit_Num,
Total_Gas,
Total_Gas_Days,
Total_Gas_Avg)
VALUES (:well_id,
:gas_quantity,
:gas_days,
:gas_average)
ON DUPLICATE KEY UPDATE
Total_Gas = Total_Gas + VALUES(Total_Gas),
Total_Gas_Days = Total_Gas_Days + VALUES(Total_Gas_Days),
Total_Gas_Avg =(Total_Gas + VALUES(Total_Gas)) / (Total_Gas_Days + VALUES(Total_Gas_Days))");
}
I'd like to see if this can be done in pure MySQL instead of having to use PHP just for the fact of using it to hold the variables.
My Result should be 1 record that is a running total for each Well. The source table may house 60-70 records for the same well, but over a few thousand different Wells.
It's a constant import process that has to be run, so it's not like there is a final table which you can just do SUM(Gas_Quantity)... etc.. on
As commented by Uueerdo, you seem to need an INSERT ... SELECT query. The role of such query is to INSERT insert the resultset returned by an inner SELECT. The inner select is an aggregate query that computes the total sum of gas and days for each well.
INSERT INTO DEP_OG_TOTALS (Well_Permit_Num, Total_Gas, Total_Gas_Days, Total_Gas_Avg)
SELECT
t.Well_Permit_Num,
SUM(t.Gas_Quantity) Total_Gas,
SUM(t.Gas_Production_Days) Total_Gas_Days
FROM DEP_OG_Production_Import t
GROUP BY t.Well_Permit_Num
ON DUPLICATE KEY UPDATE
Total_Gas = Total_Gas + t.Total_Gas,
Total_Gas_Days = Total_Gas_Days + t.Total_Gas_Days,
Total_Gas_Avg =(Total_Gas + t.Total_Gas) / (Total_Gas_Days + t.Total_Gas_Days)

Most efficient way to sum overlapping datetimes in MySQL

I'm in the process of evaluating the proposed solutions on SO related to the sum of overlapping datetimes in MySQL. I wasn't able to find out a silver-bullet solution, so would like to know if any classic/industrial-grade algorithmic procedure is available or if a custom-made needs to be developed.
Total should be 8 hours (4+4).
Proposed solution through MySQL
function final_balance($teacher_id, $aa, $teaching_id=0) {
$dbo = $this->Attendance->getDataSource();
$years=$this->Attendance->Student->Year->find('list', array('fields' => array('anno', 'data_from')));
$filteraa='attendances.start>="'.$years[$aa].'"';
$this->query('SET #interval_id = 0');
$this->query('SET #interval_end = \'1970-01-01 00:00:00\'');
$sql='SELECT
MIN(start) as start,
MAX(end) as end
FROM (
SELECT
#interval_id := IF(attendances.start > #interval_end, #interval_id + 1, #interval_id) AS interval_id,
#interval_end := IF(attendances.start < #interval_end, GREATEST(#interval_end, attendances.end), attendances.end) AS interval_end,
attendances.start,
attendances.end
FROM attendances
INNER JOIN attendance_sheets ON (
attendance_sheet_id = attendance_sheets.id AND
attendance_sheets.teacher_id='.$teacher_id.' AND '.$filteraa.' AND
attendance_sheet_status_id = 2 AND
attendance_status_id!=3'.
($teaching_id?' AND attendances.teaching_id IN ('.$teaching_id.')':'').'
)
ORDER BY attendances.start,attendances.end
) intervals GROUP BY interval_id';
// final query to sum in the temp table
$finalStatement =array(
'table' => $dbo->expression('('.$sql.')')->value,
'alias' => 'Attendance',
'fields' => array(
'DATE_FORMAT(start, \'%d/%m/%Y\') as data',
'DATE_FORMAT(start, \'%m-%Y\') as datamese',
'DATE(start) as datasql',
$teacher_id.' AS teacher_id',
'DAY(start) as giorno',
'MONTH(start) as mese',
'YEAR(start) as anno',
'SEC_TO_TIME(SUM((TIME_TO_SEC(end) - TIME_TO_SEC(start)))) as ore',
),
'conditions' => array(),
'limit' => null,
'group' => array('CONCAT(YEAR(start),MONTH(start))', 'DATE(start) WITH ROLLUP'),
'order' => null
);
$finalQuery= $dbo->buildStatement($finalStatement, $this->Attendance);
return $this->Attendance->query($dbo->expression($finalQuery)->value);
}
References
Sum amount of overlapping datetime ranges in MySQL
performs a different task
MySQL: sum time ranges exluding overlapping ones
and
MySQL: sum datetimes without counting overlapping periods twice
both seems to me like not considering all the cases
GeeksForCode: Merge Overlapping Intervals
Depending on the circumstances, the following might be useful and efficient.
Create another table that has one row per hour. Inner join that table with your table while selecting only the new column and dedupe the rows.
You can keep increasing the resolution (eg. to minutes or seconds), but that might make your code run slow.

How to use the table columns instead of variables in QueryExpression::addCase()

In CakePHPs new ORM, you can use the QueryBuilder to build (in theory) any query.
I want to select the value of one of two columns, depending on another value. In a regular query, that can be done as follows:
SELECT IF(from_id = 1, to_id, from_id) AS other_id FROM messages;
I am trying to archive the same query using the QueryBuilder and QueryExpression::addCase()
$messagesQuery = $this->Messages->find('all');
$messagesQuery->select([
'other_id' => $messagesQuery->newExpr()->addCase(
$messagesQuery->newExpr()->add(['from_id' => $this->authUser->id]),
['to_id', 'from_id'],
['integer', 'integer']
)
]);
This does not work, as the passed values are not integers, but rather table columns containing integers.
Through trial and error (using the method add() again), I got the following:
$messagesQuery = $this->Messages->find('all');
$messagesQuery->select([
'other_id' => $messagesQuery->newExpr()->addCase(
$messagesQuery->newExpr()->add(['from_id' => $this->authUser->id]),
[
$messagesQuery->newExpr()->add(['to_id']),
$messagesQuery->newExpr()->add(['from_id'])
],
['integer', 'integer']
)
]);
This results in the following query:
SELECT (CASE WHEN from_id = 1 THEN to_id END) AS `other_id` FROM messages Messages
Now, the ELSE part is missing, although the CakePHP book states:
Any time there are fewer case conditions than values, addCase will automatically produce an if .. then .. else statement.
The examples in the CakePHP book are not very helpful in this case, as they only use static integers or strings as values, for example:
#SELECT SUM(CASE published = 'Y' THEN 1 ELSE 0) AS number_published, SUM(CASE published = 'N' THEN 1 ELSE 0) AS number_unpublished FROM articles GROUP BY published
$query = $articles->find();
$publishedCase = $query->newExpr()->addCase($query->newExpr()->add(['published' => 'Y']), 1, 'integer');
$notPublishedCase = $query->newExpr()->addCase($query->newExpr()->add(['published' => 'N']), 1, 'integer');
$query->select([
'number_published' => $query->func()->sum($publishedCase),
'number_unpublished' => $query->func()->sum($unpublishedCase)
])
->group('published');
Is there a way to get the method addCase to use the two table columns as values instead of just static values?
As it turns out, I was just one logical step short of the solution in my previous edit.
As the CakePHP book correctly states:
Any time there are fewer case conditions than values, addCase will automatically produce an if .. then .. else statement.
For that to work though, both the conditions and values have to be an array, even if there is only one condition. (This the CakePHP book does not state.)
This code:
$messagesQuery = $this->Messages->find('all');
$messagesQuery->select([
'other_id' => $messagesQuery->newExpr()->addCase(
[
$messagesQuery->newExpr()->add(['from_id' => $this->authUser->id])
],
[
$messagesQuery->newExpr()->add(['to_id']),
$messagesQuery->newExpr()->add(['from_id'])
],
['integer', 'integer']
)
]);
results in this query:
SELECT (CASE WHEN from_id = 1 THEN to_id ELSE from_id END) AS `other_id` FROM messages Messages
Eureka

how to translate a very long mysql query with select and join to zend framework 1.11 model

I have this mysql query:
SELECT
freeAnswers.*,
(SELECT `districtCode`
FROM `geodatas`
WHERE `zipCode` = clients.zipCode
GROUP BY `zipCode`
LIMIT 0, 1) as districtCode,
clients.zipCode,
clients.gender,
clients.startAge,
clients.endAge,
clients.mail,
clients.facebook,
surveys.customerId,
surveys.activityId,
surveys.name as surveyName,
customers.companyName,
activities.name as activityName
FROM freeAnswers,
clients,
surveys,
customers,
activities
WHERE freeAnswers.surveyId = surveys.id
AND surveys.customerId = customers.id
AND activities.id = surveys.activityId
AND clients.id = freeAnswers.clientId
AND customers.id = 1
ORDER BY activityName asc
LIMIT 0, 10
the query is correct on my mysql server but when I try to use it in Zend Framework 1.11 model
I get this error: Mysqli prepare error: Operand should contain 1 column(s)
Please, could anyone help me to make it run well?
Best Regards,
Elaidon
Here is some code that should work. Zend_Db_Select doesn't really provide a way to select from multiple tables in the FROM clause without using a JOIN so this feels a bit hackish to me in regards to one small part of the query. Your best bet will probably be to rewrite the query using JOINs where appropriate.
$subselect = $db->select()
->from('geodatas', 'districtCode')
->where('zipCode = clients.zipCode')
->group('zipCode')
->limit(1, 0);
$from = $db->quoteIdentifier('freeAnswers') . ', ' .
$db->quoteIdentifier('clients') . ', ' .
$db->quoteIdentifier('surveys') . ', ' .
$db->quoteIdentifier('customers') . ', ' .
$db->quoteIdentifier('activities');
$select = $db->select()
->from(array('activities' => new Zend_Db_Expr($from)),
array('freeanswers.*',
'districtCode' =>
new Zend_Db_Expr('(' . $subselect . ')'),
'clients.zipCode', 'clients.gender', 'clients.startAge',
'clients.endAge', 'clients.mail', 'clients.facebook',
'clients.customerId', 'clients.activityId',
'surveyName' => 'surveys.name', 'customers.companyName',
'activityName' => 'activities.name'))
->where('freeAnswers.surveyId = surveys.id')
->where('surveys.customerId = customers.id')
->where('activities.id = surveys.activityId')
->where('clients.id = freeAnswers.clientId')
->where('customers.id = ?', 1)
->order('activityName ASC')
->limit(10, 0);
The only reason I say it is hackish is because of the line:
->from(array('activities' => new Zend_Db_Expr($from)),
Since from() really only works with one table, I create a Zend_Db_Expr and specify the correlation as the last table name in the expression. If you don't pass a Zend_Db_Expr, it will either quote your comma separated table name incorrectly, or if you pass an array of table names, it just uses the first. When you pass a Zend_Db_Expr with no name, it defaults to use AS t which also doesn't work in your case. That is why I put it as is.
That returns the exact SQL you provided except for the last thing mentioned. Here is actually what it returns:
SELECT
`freeanswers`.*,
(SELECT `geodatas`.`districtCode`
FROM `geodatas`
WHERE (zipCode = clients.zipCode)
GROUP BY `zipCode`
LIMIT 1) AS `districtCode`,
`clients`.`zipCode`,
`clients`.`gender`,
`clients`.`startAge`,
`clients`.`endAge`,
`clients`.`mail`,
`clients`.`facebook`,
`clients`.`customerId`,
`clients`.`activityId`,
`surveys`.`name` AS `surveyName`,
`customers`.`companyName`,
`activities`.`name` AS `activityName`
FROM `freeAnswers`,
`clients`,
`surveys`,
`customers`,
`activities` AS `activities`
WHERE (freeAnswers.surveyId = surveys.id)
AND (surveys.customerId = customers.id)
AND (activities.id = surveys.activityId)
AND (clients.id = freeAnswers.clientId)
AND (customers.id = 1)
ORDER BY `activityName` ASC
LIMIT 10
So that will work but eventually you will want to rewrite it using JOIN instead of specifying most of the WHERE clauses.
When dealing with subqueries and Zend_Db_Select, I find it easy to write each subquery as their own queries before writing the final query, and just insert the subqueries where they need to go and Zend_Db handles the rest.
Hope that helps.

Simplify sql query to obtain one line per id

I have a multi-table SQL query.
My need is: The query should I generate a single line by 'etablissement_id' ... and all information that I want to be back in the same query.
The problem is that this query is currently on a table where "establishment" may have "multiple photos" and suddenly, my query I currently generates several lines for the same id...
I want the following statement - LEFT JOINetablissementContenuMultimediaON etablissement.etablissement_id = etablissementContenuMultimedia.etablissementContenuMultimedia_etablissementId - only a single multimedia content is displayed. Is it possible to do this in the query below?
Here is the generated query.
SELECT DISTINCT `etablissement`. * , `etablissementContenuMultimedia`. * , `misEnAvant`. * , `quartier`. *
FROM `etablissement`
LEFT JOIN `etablissementContenuMultimedia` ON etablissement.etablissement_id = etablissementContenuMultimedia.etablissementContenuMultimedia_etablissementId
LEFT JOIN `misEnAvant` ON misEnAvant.misEnAvant_etablissementId = etablissement.etablissement_id
LEFT JOIN `quartier` ON quartier_id = etablissement_quartierId
WHERE (
misEnAvant_typeMisEnAvantId =1
AND (
misEnAvant_dateDebut <= CURRENT_DATE
AND CURRENT_DATE <= misEnAvant_dateFin
)
)
AND (
etablissement_isActive =1
)
ORDER BY `etablissement`.`etablissement_id` ASC
LIMIT 0 , 30
Here is the code used ZF
public function find (){
$db = Zend_Db_Table::getDefaultAdapter();
$oSelect = $db->select();
$oSelect->distinct()
->from('etablissement')
->joinLeft('etablissementContenuMultimedia', 'etablissement.etablissement_id = etablissementContenuMultimedia.etablissementContenuMultimedia_etablissementId')
->joinLeft('misEnAvant', 'misEnAvant.misEnAvant_etablissementId = etablissement.etablissement_id')
->joinLeft('quartier', 'quartier_id = etablissement_quartierId ')
->where ('misEnAvant_typeMisEnAvantId = 1 AND (misEnAvant_dateDebut <= CURRENT_DATE AND CURRENT_DATE <= misEnAvant_dateFin) ')
->where ('etablissement_isActive = 1')
->order(new Zend_Db_Expr('RAND()'));
$zSql = $oSelect->__toString();
if(isset($_GET['debug']) AND $_GET['debug'] == 1)
echo $zSql ;
//die();
$oResultEtablissement = $db->fetchAll($oSelect);
return $oResultEtablissement ;
}
Can you help me?
Sincerely,
If you are looking to have only one of the media displayed out of many regardless of which it may be then you can just add a limit to the query? After that you can tweak the query for ASCending or DESCending perhaps?
Is this query supposed to have images (or image as it were) for one establishment, or one image each for each active establishment? I see you have a limit 0,30 which means you're likely paginating....
If the result you want is a search for only one establishment, and the first image it comes to would work fine .. just use "limit 1" and you'll only get one result.
I took the time to redo the whole model of the database ... and now it works. There was no solution for a system as flawed