My database (mysql) tables use TIMESTAMP columns, and whenever I want them returned in a query, I want them to be queried as "UNIX_TIMESTAMP(columnname)".
How do you easily modify queries in zend framework to achieve this?
For example, the current code is:
select = $this->select();
$select->where('user_id = ?',$user_id);
return $this->fetchAll($select);
This eventually becomes:
select * from tablename where user_id = 42;
I want something that automatically finds the TIMESTAMP column and changes the resulting query to:
select user_id,name,unix_timestamp(created) where user_id = 42;
I know I can use a MySQL view to achieve this, but I'd rather avoid that.
Thanks.
RR
You should be able to specify the fields you want in the select using the $select->from() object.
Zend_Db_Select
You should end up with something like this.
$select = $this->select();
$select->from(
array('t' => 'tablename'),
array('user_id', 'name', 'UNIX_TIMESTAMP(created)')
);
$select->where('user_id = ?',$user_id);
return $this->fetchAll($select);
If you wanted to run an expression that doesn't have parenthese in the function, Use the Zend_Db_Expr() method to escape the query properly.
Related
I have a column with datetime data type and I want to build a SQL query in Zend Framework2 which compare date part with user input date.
Need to build similar part as DATE(datetime column) = '2014-09-16' with;
$select->where();
would be very grateful if someone could help on this.
Use like this:
$date = '2014.05.24';
$select->where('date(expecting_date) = "'.$date.'"');
You should use predicate expression for these kind of conditions, like :
$select = new \Zend\Db\Sql\Select(table name);
$select->where(new \Zend\Db\Sql\Predicate\Expression('DATE(datetime) = ?', '2014-09-16'));
I'm trying to match md5(ID) to an id.
SELECT *
FROM `user` u
WHERE
MD5(`user_id`) = '66f041e16a60928b05a7e228a89c3799'
this is ID = 58
I tried something like this. I know I'm close I just don't know what I'm missing
$criteria = new Criteria();
$criteria->addAnd('md5('.User::USER_ID.')', $_REQUEST['fs'], Criteria::CUSTOM);
$user = UserPeer::doSelectOne($criteria);
Any ideas?
First of all, directly using Criteria objects is deprecated not recommended. You should use Active Query classes.
Using these classes, you will be able to write stuff like this :
UserQuery::create()
->where('md5(User.Password) = ?', $_REQUEST['fs'], PDO::PARAM_STR)
->findOne();
You'll notice that I use the PhpName both of the table and the column in the query.
EDIT : For raw conditions, the parameter type has to be specified. You'll find more information on this issue.
After lenghty T&E process I managed to get it done like this
$c = new Criteria();
$c->add(UserPeer::USER_ID, "md5(user.user_id) = \"".$_REQUEST['fs']."\"", Criteria::CUSTOM); // risk of SQL injection!!
$saved_search = UserPeer::doSelectOne($c);
For some reason PropelORM though that $_REQUEST['fs'] was name of the table rather than the value. \"" solved the problem.
So I use the PDO for a DB connection like this:
$this->dsn[$key] = array('mysql:host=' . $creds['SRVR'] . ';dbname=' . $db, $creds['USER'], $creds['PWD']);
$this->db[$key] = new PDO($this->dsn[$key]);
Using PDO I can then execute a MySQL SELECT using something like this:
$sql = "SELECT * FROM table WHERE id = ?";
$st = $db->prepare($sql);
$st->execute($id);
$result = $st->fetchAll();
The $result variable will then return an array of arrays where each row is given a incremental key - the first row having the array key 0. And then that data will have an array the DB data like this:
$result (array(2)
[0]=>[0=>1, "id"=>1, 1=>"stuff", "field1"=>"stuff", 2=>"more stuff", "field2"=>"more stuff" ...],
[1]=>[0=>2, "id"=>2, 1=>"yet more stuff", "field1"=>"yet more stuff", 2=>"even more stuff", "field2"=>"even more stuff"]);
In this example the DB table's field names would be id, field1 and field2. And the result allows you to spin through the array of data rows and then access the data using either a index (0, 1, 2) or the field name ("id", "field1", "field2"). Most of the time I prefer to access the data via the field names but access via both means is useful.
So I'm learning the ruby-mysql gem right now and I can retrieve the data from the DB. However, I cannot get the field names. I could probably extract it from the SQL statement given but that requires a fair bit of coding for error trapping and only works so long as I'm not using SELECT * FROM ... as my SELECT statement.
So I'm using a table full of State names and their abbreviations for my testing. When I use "SELECT State, Abbr FROM states" with the following code
st = #db.prepare(sql)
if empty(where)
st.execute()
else
st.execute(where)
end
rows = []
while row = st.fetch do
rows << row
end
st.close
return rows
I get a result like this:
[["Alabama", "AL"], ["Alaska", "AK"], ...]
And I'm wanting a result like this:
[[0=>"Alabama", "State"=>"Alabama", 1=>"AL", "Abbr"=>"AL"], ...]
I'm guessing I don't have the way inspect would display it quite right but I'm hoping you get the idea by now.
Anyway to do this? I've seen some reference to doing this type of thing but it appears to require the DBI module. I guess that isn't the end of the world but is that the only way? Or can I do it with ruby-mysql alone?
I've been digging into all the methods I can find without success. Hopefully you guys can help.
Thanks
Gabe
You can do this yourself without too much effort:
expanded_rows = rows.map do |r|
{ 0 => r[0], 'State' => r[0], 1 => r[1], 'Abbr' => r[1] }
end
Or a more general approach that you could wrap up in a method:
columns = ['State', 'Abbr']
expanded_rows = rows.map do |r|
0.upto(names.length - 1).each_with_object({}) do |i, h|
h[names[i]] = h[i] = r[i]
end
end
So you could collect up the rows as you are now and then pump that array of arrays through something like what's above and you should get the sort of data structure you're looking for out the other side.
There are other methods on the row you get from st.fetch as well:
http://rubydoc.info/gems/mysql/2.8.1/Mysql/Result
But you'll have to experiment a little to see what exactly they return as the documentation is, um, a little thin.
You should be able to get the column names out of row or st:
http://rubydoc.info/gems/mysql/2.8.1/Mysql/Stmt
but again, you'll have to experiment to figure out the API. Sorry, I don't have anything set up to play around with the MySQL API that you're using so I can't be more specific.
I realize that php programmers are all cowboys who think using a db layer is cheating, but you should really consider activerecord.
I want to add a "CONVERT" stored procedure like this:
SELECT id, value, CONVERT(value, DECIMAL) AS ordred_value FROM test ORDER BY ordred_value;
to this collection query :
$collection = $this->getAssociatedProductCollection($product)
->addAttributeToSelect('*')
->addFilterByRequiredOptions()
->setPositionOrder()
->addStoreFilter($this->getStoreFilter($product))
->addAttributeToFilter('status', array('in' => $this->getStatusFilters($product)))
->addAttributeToSort('my_attribute', 'DESC');
for the purpose of ordering the associated products by my custom attribute "my_attribute" that have numeric values in text fields.
Thanks for help.
I'm not sure it's the bast solution, but you can do it like this:
<?php
$collection->getSelct()->columns(array('converted_value' => 'CONVERT(e.my_attribute, DECIMAL)'));
It will add a new column to result. Next sort the collection using it's select as above and the order method.
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.