I have an SQL query which is fetching me the data correcting from sqlplus. When I try to convert the query such that I can implement in the catalyst controller, I am getting an error message saying there is no relation between the tables Feature and Featurealias.As I am new to catalyst and DBIx::Class, I am not able to figure out what could be the probable mistake. Can any body help me fix this issue.
Below is the SQL query and the code which I a trying to implement in catalyst Controller.
my#sourceid=$c->model('Gene::Featurealias')->search({
'feature.typeid'=>4,
},
{
join=>'feature',
distinct=>1,
columns=>[qw/sourceid/]
});
SQL query:
select distinct FeatureAlias.SourceID From FeatureAlias join Feature on FeatureAlias.FeatureID=Feature.FeatureID where Feature.TypeID=4;
Defined in Feature.pm
__PACKAGE__->has_many( "featurealias",
"...Result::Featurealias");
Defined in Featurealias.pm
__PACKAGE__->belongs_to("featureid",
"...::Result::Feature");
Thanks in advance.
You've created a relationship named 'featureid' in your Featurealias class but asked DBIC to join one named 'feature'.
Related
What's the best approch to have a dynamic query like
select $dynamic_columns from table
But also prevent error like column not found and get result with available columns. considering $dynamic_columns is given by end users.
One approach would be to store the schema in java object and filter it. Again if schema is update in DB we will need to update the schema java object cache. is there any better way to handle this?
Be careful with this as it is more vulnerable to SQL injection.
Never let the user type something into a text field, instead build a
list for them to select from.
For building the list, I think the best approach is to use the JDBC method DatabaseMetaData.getColumns(...) to retrieve a list of columns for a table. I don't think there's a need to cache anything.
I have a question about Laravel Eloquent ORM, can i use this tool to create Postgresql array_agg?, I have this query:
this query returns me:
[{"id":1, "contact_name":"name", "description":"description", "discharge":0, "latitude":null, "longitude":null, "town":null, "country":null, "province":null,
"numbers":"{77777,888888}", "emails":"{email#email.com, email2#email2.com}"}]
And im trying to create this query with eloquent: i have this code:
This second query returns me all the previous data except the numbers and emails, because i dont have any idea how to put array_agg in this query.
I appreciate any help!
Problem
I need to execute a raw SQL query from LINQ to Entities and retrieve the result. The query returns the current date/time from the SQL Server instance, and looks like this:
SELECT GETDATE()
[Edit]
I'm using a data model that was created database-first.
[/Edit]
What I've Tried
I've researched this issue on the interwebz and been unable to find a technique to do this. I was able to learn how to do this using LINQ to SQL, but since I'm not using that, it's of no help.
Heres what you are after
var time = context.Database.SqlQuery<DateTime>("SELECT GETDATE()").FirstOrDefault();
You can read more about raw sql and EF here http://msdn.microsoft.com/en-us/data/jj592907.aspx
I know how to use "DISTINCT" in Doctrine 2, but I really need to use "DISTINCT ON (field)" and I don't know how to do this with the QueryBuilder.
My SQL query looks like:
SELECT DISTINCT ON (currency) currency, amount FROM payments ORDER BY currency
And this query works perfect, but I can't use it with the QueryBuilder. Maybe I could write this query on some other way?
I would suggest that the SELECT DISTINCT ON (..) construct that PostgreSQL supports is outside the Object Relational Model (ORM) that is central to Doctrine. Or, perhaps put another way, because SELECT DISTINCT ON (..) is rare in SQL implementations Doctrine haven't coded for it.
Regardless of the actual logic for it not working, I would suggest you try Doctrine's "Native SQL". You need to map the results of your query to the ORM.
With NativeQuery you can execute native SELECT SQL statements and map
the results to Doctrine entities or any other result format supported
by Doctrine.
In order to make this mapping possible, you need to describe to
Doctrine what columns in the result map to which entity property. This
description is represented by a ResultSetMapping object.
With this feature you can map arbitrary SQL code to objects, such as
highly vendor-optimized SQL or stored-procedures.
SELECT DISTINCT ON (..) falls into vendor-optimized SQL I think, so using NativeQuery should allow you to access it.
Doctrine QueryBuilder has some limitations. Even if I didn't check if it's was possible with query builder, I do not hesitate to use DQL when I do not know how to write the query with query builder.
Check theses examples at
http://doctrine-orm.readthedocs.org/en/latest/reference/dql-doctrine-query-language.html#dql-select-examples
Hope this help.
INDEX BY can be used in DQL, allowing first result rows indexed by the defined string/int field to be overwritten by following ones with the same index:
SELECT
p.currency,
p.amount
FROM Namespace\To\Payments p INDEX BY p.currency
ORDER BY p.currency ASC
DQL - EBNF - INDEX BY
I'm using Zend Framework for my website and I'd like to retrieve some data from my PostgreSQL database.
I have a request like :
SELECT DISTINCT ON(e.id) e.*, f.*, g.* FROM e, f, g
WHERE e.id = f.id_e AND f.id = g.id_f
This request works well but I don't know how to convert the DISTINCT ON(e.id) with Zend.
It seems that I can get DISTINCT rows but no distinct columns.
$select->distinct()->from("e")->join("f", "e.id = f.id_e")
->join("g", "f.id = g.id_f");
Any idea on how to make a select with distinct column ?
Thanks for help
You probably can't do this with Zend Framework since distinct on is not part of the SQL standard (end of page in Postgres documentation). Although Postgres supports it, I would assume its not part of Zend Framework because you could in theory configure another database connection which does not offer support.
If you know in advance that you're developing for a specific database (Postgres in this case), you could use manually written statements instead. You'll gain more flexibility within the queries and better performance at the cost of no longer being able to switch databases.
You would then instantiate a Zend_Db_Apdapter for Postgres. There a various methods available to get results for SQL queries which are described in the frameworks documentation starting at section Reading Query Results. If you choose to go this route I'd recommend to create an own subclass of the Zend_Db_Adapter_Pgsql class. This is to be able to convert data types and throw exceptions in case of errors instead of returning ambiguous null values and hiding error causes.