Using activerecord I made this query
AdImage.select("ad_images.id, ad_images.locale_id, ad_campaigns.click_url,
ad_campaigns.default_ad_image_id").joins("left outer join ad_campaigns on
ad_campaigns.id = ad_images.ad_campaign_id").where("ad_images.ad_campaign_id" => 1)
which generates the following sql query:
SELECT ad_images.id, ad_images.locale_id, ad_campaigns.click_url,
ad_campaigns.default_ad_image_id FROM "ad_images" left outer join ad_campaigns on
ad_campaigns.id = ad_images.ad_campaign_id WHERE "ad_images"."ad_campaign_id" = 1
and the result is the following:
=> [#<AdImage id: 22, click_url: "market://details?id=com.mobiata.flighttrack",
locale_id: 2>]
which is wrong.
So I used ActiveRecord::Base.connection.execute method to directly run the sql query:
ActiveRecord::Base.connection.execute("SELECT ad_campaigns.click_url, ad_images.id,
ad_images.locale_id, ad_campaigns.default_ad_image_id FROM ad_campaigns inner join
ad_images on ad_campaigns.id = ad_images.ad_campaign_id WHERE ad_images.ad_campaign_id = 1")
which returns the following:
[{"click_url"=>"market://details?id=com.mobiata.flighttrack", "id"=>22, "locale_id"=>2,
"default_ad_image_id"=>22, 0=>"market://details?id=com.mobiata.flighttrack", 1=>22,
2=>2, 3=>22}]
which has the strange repetition in it.
The only difference between the first and the second is "ad_images" vs ad_images in the table names.
My questions are:
1) I don't understand what makes this difference.
2) Why does the second query returns the garbage in SQLite3 while it doesn't happen in MySQL server?
I ended up with using "ActiveRecord::Base.connection.execute" instead of using Rails' ActiveRecord helpers. There doesn't seem to be other solutions to it.
It turns out that you should use the index values instead of double quoted column names when you call values. Otherwise you will bump into Type errors when used in production with MySQL.
Related
I wrote a SQL query to find the desired output for my project. I was working fine with the correct output. But suddenly it started to give error and in the SQL query, there is some additional apoatrophe in. How to resolve it?
I tried to add the query to $this->db->query(); but still no use.
public function getStudentConut($id) {
$this->db->select('students.id')
->from('students')
->join('bp','students.pbp = bp.id','left')
->where(condition 1)
->where(condition 2);
$query1 = $this->db->get_compiled_select();
$this->db->select('students.id')
->from('students')
->join('bp','students.dbp = bp.id','left')
->where(condition 1)
->where(condition 2);
$query2 = $this->db->get_compiled_select();
$this->db->select('COUNT(id) as stud_count')
->from('('.$query1." UNION ALL ".$query2.') X')
->group_by('X.id');
$results = $this->db->get();
return $results->num_rows();
}
It was giving correct count earlier. But without any new changes, it started to give the error.
Now I get error:
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '.id`` WHERE ``bp.some_value`` IS NULL AND ``students.`schoo' at line 2
SELECT COUNT(id) as stud_count FROM (SELECT students.id`` FROM ``students`` LEFT JOIN ``bp`` ON ``students.pbp`` = ``bp.id`` WHERE ``bp..Some other condition.. UNION ALL SELECT students.idFROMstudentsLEFT JOINbpONstudents.dbp=bp.id..some other condition....) X GROUP BYX.id`
I think the issue (at least with the double `) is that CodeIgniter isn't very good with subqueries and such. Basically every time you get the compiled select statement it already has the escape identifiers and then you are putting it in the from statement at the end which will add additional escape identifiers on top of that.
`->from('('.$query1." UNION ALL ".$query2.') X')`
Unfortunately, unlike other methods like set, from doesn't have a 2nd parameter that allows you to set escaping to false (which is what I think you need).
I suggest trying this:
$this->db->_protect_identifiers = FALSE;
$this->db->select('COUNT(id) as stud_count')
->from('('.$query1." UNION ALL ".$query2.') X')
->group_by('X.id');
$results = $this->db->get();
$this->db->_protect_identifiers = TRUE;
and also look in to this: ->where(condition 2); which I'm pretty sure shouldn't compile due to lack of quotes. You probably don't want this escaped so you can do ->where('condition 2', '', false); as per: https://www.codeigniter.com/user_guide/database/query_builder.html#CI_DB_query_builder::where
When all else fails, just know that CodeIgniter has some limitations with "advanced" queries and that maybe you should write it out manually as a string utilizing $this->db->escape_str(...) for escaping user input vars, and $this->db->query(...) to run the SQL.
I am trying to update a website from SS 2.4 to SS 3.1 and have been digging around the web on this issue for a while now.
The old code looks like this...
return DataObject::get('SupportItem', "SupportItemType = '$itemType' AND ProductPageID = $productID", null, 'INNER JOIN SupportItem_Products ON SupportItem_Products.SupportItemID = SupportItem.ID');
I am trying to switch out of the deprecated INNER JOIN and DataObject::get to the now current innerJoin and DataobjectName::get. This is what I have for the new code
$productID = $this->productToView->ID;
return SupportProductListingPage::get()->innerJoin('SupportItem_Products', '"SupportItem_Products"."SupportItemID" = "SupportItem"."ID"', null)->filter(array('SupportItemType'=>'$itemType', 'ProductPageID' => '$productID'));
It should be noted that the "SupportItemID" column exists in "SupportItem_Products" and the "ID" column exists in "SupportItem". However, "SupportItemID" does not exist in the "SupportItem" table.
I am receiving the below error when loading the page...
[User Error] Couldn't run query: SELECT DISTINCT count(DISTINCT "SiteTree"."ID") AS "0" FROM "SiteTree" LEFT JOIN "Page" ON "Page"."ID" = "SiteTree"."ID" INNER JOIN "SupportItem_Products" ON "SupportItem_Products"."SupportItemID" = "SupportItem"."ID" WHERE ("ProductPageID" = '$productID') AND ("SiteTree"."ClassName" IN ('SupportProductListingPage')) Unknown column 'SupportItem.ID' in 'on clause'
Can anyone help?
It seems that you are doing the join wrongly. The error message says that Unknown column 'SupportItem.ID' in 'on clause.
The original starts with:
DataObject::get('SupportItem', "SupportItemType = '
And yours starts with:
return SupportProductListingPage::get()->innerJoin('SupportItem_Products',
This says basically says join SupportItem_Products with SupportProductListingPage with a table that`s not part of your query at all.
This should be the innerjoin that you actually need (not tested of course):
SupportItem::get()->innerJoin('SupportItem_Products','"SupportItem_Products"."SupportItemID" = "SupportItem"."ID"');
With that the query should be right if the class relations are declared with the right has/belongs variables.
Also your filter bit wont probably work as expected:
filter(array('SupportItemType'=>'$itemType', 'ProductPageID' => '$productID'))
You are trying to use a variable inside single quotes. So either do
'SupportItemType'=>"$itemType" or 'SupportItemType'=>$itemType
I am pretty new to hibernate again, so this might be a noobish question ;).
Without to_days, but clustered by timestamp it works like this:
CriteriaQuery<Tuple> query = criteriaBuilder.createQuery(Tuple.class);
Root<Session> sessionRoot = query.from(Session.class);
query.multiselect(
sessionRoot.get("time").alias("time"),
criteriaBuilder.count(sessionRoot).alias("count")
);
query.groupBy(sessionRoot.get("time"));
List<Tuple> results = this.executeQuery(query);
So I recieve:
time|count
13721938721|1
13721938722|2
13721938723|3
13721938724|4
13721938725|2
13721938726|1
13721938727|4
But this are all sessioncounts for each millisecond, but I need those clustered by day and not by timestamp: thus I use to_days in plain mysql.
In mysql I perform this query:
SELECT TO_DAYS(`time`) AS `days`, COUNT(*) as `count` FROM sessions WHERE 1 GROUP BY `days`
This gives me:
days|count
777594|123
777595|60
777596|61
777597|74
But I have no idea, yet: how to achieve the same thing with javax.persistence.criteria.CriteriaBuilder and CriteriaQuery in hibernate?
I dont know how to do it with criteriaBuilder, but i do know how in Hibernate 4 criteria api:
query.setProjection(
Projections.sqlProjection(
"TO_DAYS(time) as days",
new String[]{"days"},
new Type[]{StandardBasicTypes.INTEGER}
)
);
sqlProjection allows you to cast or convert data types, but careful, using a projection will only retrieve the fileds you specify in it, and the resulting list will come up like this:
List<Object[]> results = this.executeQuery(query);
But you can make hibernate do a alias match with the properties using a result transformer:
query.setResultTransformer(new AliasToBeanResultTransformer(Session.class));
and the list comes out like it normally does:
List<Session.class> results = this.executeQuery(query);
Sorry i could not provide a criteriaBuilder solution, but i hope this gets you in the right track.
After some investigation, it turned out, that HQL does not support TO_DAYS. Since I want to make it possible for MySQL and other databases, this is my final solution:
Query q = entityManager.createQuery("SELECT concat(day(e.time), '-', month(e.time), '-', year(e.time)) AS days, COUNT(*) FROM Event e GROUP BY concat(day(e.time), '-', month(e.time), '-', year(e.time))");
The result is:
3-5-2012|980
4-5-2012|200
10-6-2012|123
12-6-2012|144
13-11-2012|500
So afterwards I convert all ugly date strings into proper milliseconds in java and have the data, which I need.
I have the following query:
select subclasses.id,participants_subclasses.participant_id
from subclasses
left outer join participants_subclasses on
participants_subclasses.participant_id = ?
and subclasses.id = participants_subclasses.subclass_id
where
subclasses.classification_id = ?
and subclasses.showhover
order by subclasses.seq,
IF(LEFT(subclasses.code, 1) = '<',
Extractvalue(subclasses.code, "//texts/text/content"),
subclasses.code)
The above query is processing a table where the code column sometimes has text and sometimes has XML with text inside a tag. The above query works. The side-effect is that a code value cannot start with a "<" which should be acceptable, but the order by would mistake it for XML content. The query below would be more specific and accurate:
select subclasses.id,participants_subclasses.participant_id
from subclasses
left outer join participants_subclasses on
participants_subclasses.participant_id = ?
and subclasses.id = participants_subclasses.subclass_id
where
subclasses.classification_id = ?
and subclasses.showhover
order by subclasses.seq,
IF(LEFT(subclasses.code, 5) = '<?xml',
Extractvalue(subclasses.code, "//texts/text/content"),
subclasses.code)
However this variation checking the XML header in the content fails with a "NameInput Array does not match ?" error in MySQL. It appears that the ? inside <?xml literal is being mistaken for a bind target. And I am passing 2 values to be bound - which again is correct.
So my question is - how do I get the <?xml literal to not be mistaken for a bind value target???
SOLVED
This turns out to be a bug in ADODB interface from phpLens, and NOT in MySQL itself. It exists in current version which is 5.17 for PHP5.
I've stumbled upon a very strange LINQ to SQL behaviour / bug, that I just can't understand.
Let's take the following tables as an example: Customers -> Orders -> Details.
Each table is a subtable of the previous table, with a regular Primary-Foreign key relationship (1 to many).
If I execute the follow query:
var q = from c in context.Customers
select (c.Orders.FirstOrDefault() ?? new Order()).Details.Count();
Then I get an exception: Could not format node 'Value' for execution as SQL.
But the following queries do not throw an exception:
var q = from c in context.Customers
select (c.Orders.FirstOrDefault() ?? new Order()).OrderDateTime;
var q = from c in context.Customers
select (new Order()).Details.Count();
If I change my primary query as follows, I don't get an exception:
var q = from r in context.Customers.ToList()
select (c.Orders.FirstOrDefault() ?? new Order()).Details.Count();
Now I could understand that the last query works, because of the following logic:
Since there is no mapping of "new Order()" to SQL (I'm guessing here), I need to work on a local list instead.
But what I can't understand is why do the other two queries work?!?
I could potentially accept working with the "local" version of context.Customers.ToList(), but how to speed up the query?
For instance in the last query example, I'm pretty sure that each select will cause a new SQL query to be executed to retrieve the Orders. Now I could avoid lazy loading by using DataLoadOptions, but then I would be retrieving thousands of Order rows for no reason what so ever (I only need the first row)...
If I could execute the entire query in one SQL statement as I would like (my first query example), then the SQL engine itself would be smart enough to only retrieve one Order row for each Customer...
Is there perhaps a way to rewrite my original query in such a way that it will work as intended and be executed in one swoop by the SQL server?
EDIT:
(longer answer for Arturo)
The queries I provided are purely for example purposes. I know they are pointless in their own right, I just wanted to show a simplistic example.
The reason your example works is because you have avoided using "new Order()" all together. If I slightly modify your query to still use it, then I still get an exception:
var results = from e in (from c in db.Customers
select new { c.CustomerID, FirstOrder = c.Orders.FirstOrDefault() })
select new { e.CustomerID, Count = (e.FirstOrder != null ? e.FirstOrder : new Order()).Details().Count() }
Although this time the exception is slightly different - Could not format node 'ClientQuery' for execution as SQL.
If I use the ?? syntax instead of (x ? y : z) in that query, I get the same exception as I originaly got.
In my real-life query I don't need Count(), I need to select a couple of properties from the last table (which in my previous examples would be Details). Essentially I need to merge values of all the rows in each table. Inorder to give a more hefty example I'll first have to restate my tabels:
Models -> ModelCategoryVariations <- CategoryVariations -> CategoryVariationItems -> ModelModuleCategoryVariationItemAmounts -> ModelModuleCategoryVariationItemAmountValueChanges
The -> sign represents a 1 -> many relationship. Do notice that there is one sign that is the other way round...
My real query would go something like this:
var q = from m in context.Models
from mcv in m.ModelCategoryVariations
... // select some more tables
select new
{
ModelId = m.Id,
ModelName = m.Name,
CategoryVariationName = mcv.CategoryVariation.Name,
..., // values from other tables
Categories = (from cvi in mcv.CategoryVariation.CategoryVariationItems
let mmcvia = cvi.ModelModuleCategoryVariationItemAmounts.SingleOrDefault(mmcvia2 => mmcvia2.ModelModuleId == m.ModelModuleId) ?? new ModelModuleCategoryVariationItemAmount()
select new
{
cvi.Id,
Amount = (mmcvia.ModelModuleCategoryVariationItemAmountValueChanges.FirstOrDefault() ?? new ModelModuleCategoryVariationItemAmountValueChange()).Amount
... // select some more properties
}
}
This query blows up at the line let mmcvia =.
If I recall correctly, by using let mmcvia = new ModelModuleCategoryVariationItemAmount(), the query would blow up at the next ?? operand, which is at Amount =.
If I start the query with from m in context.Models.ToList() then everything works...
Why are you looking into only the individual count without selecting anything related to the customer.
You can do the following.
var results = from e in
(from c in db.Customers
select new { c.CustomerID, FirstOrder = c.Orders.FirstOrDefault() })
select new { e.CustomerID, DetailCount = e.FirstOrder != null ? e.FirstOrder.Details.Count() : 0 };
EDIT:
OK, I think you are over complicating your query.
The problem is that you are using the new WhateverObject() in your query, T-SQL doesnt know anyting about that; T-SQL knows about records in your hard drive, your are throwing something that doesn't exist. Only C# knows about that. DON'T USE new IN YOUR QUERIES OTHER THAN IN THE OUTER MOST SELECT STATEMENT because that is what C# will receive, and C# knows about creating new instances of objects.
Of course is going to work if you use ToList() method, but performance is affected because now you have your application host and sql server working together to give you the results and it might take many calls to your database instead of one.
Try this instead:
Categories = (from cvi in mcv.CategoryVariation.CategoryVariationItems
let mmcvia =
cvi.ModelModuleCategoryVariationItemAmounts.SingleOrDefault(
mmcvia2 => mmcvia2.ModelModuleId == m.ModelModuleId)
select new
{
cvi.Id,
Amount = mmcvia != null ?
(mmcvia.ModelModuleCategoryVariationItemAmountValueChanges.Select(
x => x.Amount).FirstOrDefault() : 0
... // select some more properties
}
Using the Select() method allows you to get the first Amount or its default value. I used "0" as an example only, I dont know what is your default value for Amount.