i'm having a problem in converting a mariaDB query to coldbox criteriaBuilder. i not quite understand how to join multi table using criteriaBuilder in coldbox. this is my mariaDB query :
select TerminalInst.* from TerminalInst
inner join Terminal on TerminalInst.terminal_id = Terminal.id
inner join custinst on TerminalInst.custinst_id = custinst.instID
where Terminal.description like '%value%'
how to convert this query to criteriaBuilder? please help me..
Try something like this (within a handler):
property name="terminalInstService" inject="model:terminalInstService"; //for cbox 3.8.x
property name="terminalInstService" inject="model"; // for cbox 4.2.x
cr = terminalInstService.newCriteria();
cr.createAlias('terminals','t')
.createAlias('custinsts','c')
.ilike('t.description','%value%');
results = cr.list();
where
terminals = relationship name between TerminalInst and Terminal
custinsts = relationship name between TerminalInst and custinst
and ilike is for case in-sensitive like
Related
I am comming to ASP .NET Core from PHP w/ MySQL.
The problem:
For the illustration, suppose the following two tables:
T: {ID, Description, FK} and States: {ID, ID_T, Time, State}. There is 1:n relationship between them (ID_T references T.ID).
I need all the records from T with some specific value of FK (lets say 1) along with the related newest record in States (if any).
In terms of SQL it can be written as:
SELECT T.ID, T.Description, COALESCE(s.State, 0) AS 'State' FROM T
LEFT JOIN (
SELECT ID_T, MAX(Time) AS 'Time'
FROM States
GROUP BY ID_T
) AS sub ON T.ID = sub.ID_T
LEFT JOIN States AS s ON T.ID = s.ID_T AND sub.Time = s.Time
WHERE FK = 1
I am struggling to write an efficient equivalent query in LINQ (or the fluent API). The best working solution I've got so far is:
from t in _context.T
where t.FK == 1
join s in _context.States on t.ID equals o.ID_T into _s
from s in _s.DefaultIfEmpty()
let x = new
{
id = t.ID,
time = s == null ? null : (DateTime?)s.Time,
state = s == null ? false : s.State
}
group x by x.id into x
select x.OrderByDescending(g => g.time).First();
When I check the resulting SQL query in the output window when executed it is just like:
SELECT [t].[ID], [t].[Description], [t].[FK], [s].[ID], [s].[ID_T], [s].[Time], [s].[State]
FROM [T] AS [t]
LEFT JOIN [States] AS [s] ON [T].[ID] = [s].[ID_T]
WHERE [t].[FK] = 1
ORDER BY [t].[ID]
Not only it selects more columns than I need (in the real scheme there are more of them). There is no grouping in the query so I suppose it selects everything from the DB (and States is going to be huge) and the grouping/filtering is happening outside the DB.
The questions:
What would you do?
Is there an efficient query in LINQ / Fluent API?
If not, what workarounds can be used?
Raw SQL ruins the concept of abstracting from a specific DB technology and its use is very clunky in current Entity Framework Core (but maybe its the best solution).
To me, this looks like a good example for using a database view - again, not really supported by Entity Framework Core (but maybe its the best solution).
What happens if you try to do a more straight forward translation to LINQ?
var latestState = from s in _context.States
group s by s.ID_T into sg
select new { ID_T = sg.Key, Time = sg.Time.Max() };
var ans = from t in _context.T
where t.FK == 1
join sub in latestState on t.ID equals sub.ID_T into subj
from sub in subj.DefaultIfEmpty()
join s in _context.States on new { t.ID, sub.Time } equals new { s.ID, s.Time } into sj
from s in sj.DefaultIfEmpty()
select new { t.ID, t.Description, State = (s == null ? 0 : s.State) };
Apparently the ?? operator will translate to COALESCE and may handle an empty table properly, so you could replace the select with:
select new { t.ID, t.Description, State = s.State ?? 0 };
OK. Reading this article (almost a year old now), Smit's comment to the original question and other sources, it seems that EF Core is not really production ready yet. It is not able to translate grouping to SQL and therefore it is performed on the client side, which may be (and in my case would be) a serious problem. It corresponds to the observed behavior (the generated SQL query does no grouping and selects everything in all groups). Trying the LINQ queries out in Linqpad it always translates to a single SQL query.
I have downgraded to EF6 following this article. It required some changes in my model's code and some queries. After changing .First() to .FirstOrDefault() in my original LINQ query it works fine and translates to a single SQL query selecting only the needed columns. The generated query is much more complex than it is needed, though.
Using a query from NetMage's answer (after small fixes), it results in a SQL query almost identical to my own original SQL query (there's only a more complex construct than COALESCE).
var latestState = from s in _context.States
group s by s.ID_T into sg
select new { ID = sg.Key, Time = sg.Time.Max() };
var ans = from t in _context.T
where t.FK == 1
join sub in latestState on t.ID equals sub.ID into subj
from sub in subj.DefaultIfEmpty()
join s in _context.States
on new { ID_T = t.ID, sub.Time } equals new { s.ID_T, s.Time }
into sj
from s in sj.DefaultIfEmpty()
select new { t.ID, t.Description, State = (s == null ? false : s.State) };
In LINQ it's not as elegant as my original SQL query but semantically it's the same and it does more or less the same thing on the DB side.
In EF6 it is also much more convenient to use arbitrary raw SQL queries and AFAIK also the database views.
The biggest downside of this approach is that full .NET framework has to be targeted, EF6 is not compatible with .NET Core.
i want to rebuild this SQL Query as AX Query.
I tried it in several ways, but I don't get it.
I am not completely new to AX queries, but I only have experience with some simple queries not with such complex SQL queries.
SELECT * FROM ( SELECT DH.[RECID] AS RECID_DIMENSIONHIERARCHY
,DH.[NAME] AS NAME__DIMENSIONHIERARCHY
,DH.[DESCRIPTION] AS DESC__DIMENSIONHIERARCHY
,DH.[PARTITION] AS PARTITION_DIMENSIONHIERARCHY
,DL.[DIMENSIONATTRIBUTE] AS RECID_DIMENSIONATTRIBUTE
,DA.[NAME] AS NAME_DIMENSIONATTRIBUTE
,DN.[RECID] AS RECID_DIMENSIONCONSTRAINTNODE
,DNC.[RECID] AS RECID_DIMENSIONCONSTRAINTNODECRITERIA
,DNC.[RANGETO] AS #Owner
,DNCR.[WILDCARDSTRING] AS #Agreement
FROM (SELECT * FROM [dbo].[DIMENSIONHIERARCHY]
WHERE [STRUCTURETYPE] = 1 AND [NAME] LIKE 'AG-OW%'
) AS DH
INNER JOIN [dbo].[DIMENSIONHIERARCHYLEVEL] AS DL
ON DH.[RECID] = DL.[DIMENSIONHIERARCHY]
AND DH.[PARTITION] = DL.[PARTITION]
INNER JOIN [dbo].[DIMENSIONATTRIBUTE] AS DA
ON DL.[DIMENSIONATTRIBUTE] = DA.[RECID]
AND DL.[PARTITION] = DA.[PARTITION]
INNER JOIN [dbo].[DIMENSIONCONSTRAINTNODE] AS DN
ON DL.[RECID] = DN.[DIMENSIONHIERARCHYLEVEL]
AND DL.[PARTITION] = DN.[PARTITION]
INNER JOIN [dbo].[DIMENSIONCONSTRAINTNODECRITERIA] AS DNC
ON DN.[RECID] = DNC.[DIMENSIONCONSTRAINTNODE]
AND DN.[PARTITION] = DNC.[PARTITION]
INNER JOIN [dbo].[DIMENSIONCONSTRAINTNODECRITERIA] AS DNCR
ON DN.[PARENTCONSTRAINTNODE] = DNCR.[DIMENSIONCONSTRAINTNODE]
AND DN.[PARTITION] = DNCR.[PARTITION]
) AS Sub
You need to break down your query and implement it in small chunks. Then combine all of it to get the desired result.
There are two ways to create query in X++.
Create query using select statement for example:
Select * from HcmWorker join * from DirPerson
where DirPerson.RecId == HcmWorker.Person
See this link : Select statement syntax
Create query with AOT structure. You might want to have a look at the following link:
Create query in AOT by using X++
I've been evaluating Delphi XE4 (compiling against win32, but final platform will be iOS) and I need to create SQLite database (no problem with that) and make some queries. This is one query I'd like to use:
select id as _id, name, note as description from notes
And this is my code:
q := TSQLQuery.Create(nil);
try
q.SQLConnection := MainForm.sqlite1;
q.SQL.Text := sql;
q.Open;
finally
q.Free;
end;
The problem is that query returns original field names (id, name, note), not the one I used (_id, name, description).
q.Fields[0].FieldName = 'id' //it should be _id
q.Fields[2].FieldName = 'note' //it should be description
That makes all sorts of problems. Using
count(*) as myfield
returns
q.Fields[0].FieldName = Column0 //it should be myfield
that is not acceptable.
Anybody had same problems?
In order to get the proper alias names of the fields, you must add the ColumnMetaDataSupported param to the Params property of the TSQLConnectioncomponent with the False value.
These are my tables:
Table Gift:
-id
-price
...
Table Couple:
-id
-name
...
table registry: //provide a many-many relation between gifts and couples
-id
-coupleId
-giftId
table purchase:
-amount
-registryId
I already wrote a sql query to get all the gift info for a specific couple
$qb = $this->createQueryBuilder('g') //gift
->from('\BBB\GiftBundle\Entity\Registry', 'reg')
->select('g.id , g.price')
->where('reg.gift = g.id')
->andWhere('reg.couple = :coupleID')
->orderBy('reg.id','DESC')
->setParameter('coupleID', $coupleID);
OR
SELECT g.id , g.price,
FROM gift g, registry reg
WHERE reg.gift_id = g.id AND reg.couple_id = 1
I also want to get the total amount that for the gifts that have been bought (if any)
EX. SUM(purchase.amount) as totalContribute
I have tried:
$qb = $this->createQueryBuilder('g')
->from('\BBB\GiftBundle\Entity\Purchase', 'p')
->from('\BBB\GiftBundle\Entity\Registry', 'reg')
->select('g.id , g.price')
->addSelect('SUM(p.amount) as totalContribute')
->leftJoin('p','pp', 'ON','reg.id = pp.registry')
->where('reg.gift = g.id')
->andWhere('reg.couple = :coupleID')
->orderBy('reg.id','DESC')
->setParameter('coupleID', $coupleID);
but it gives me the following error:
[Semantical Error] line 0, col 145 near 'pp ON reg.id': Error: Identification Variable p used in join path expression but was not defined before.
First of all, you should define join condition in your SQL statements after joins, not in WHERE clause. The reason is that it's really not efficient. So the query shoul look like:
SELECT g.id , g.price,
FROM gift g JOIN registry reg ON reg.gift_id = g.id
WHERE reg.couple_id = 1
But about your Doctrine query, You get error because you're defining joins in wrong way. Your query should more like:
$qb = $this->createQueryBuilder('g') // You don't have put "from" beacuse I assume you put this into GiftRepository and then Doctrine knows that should be \BBB\GiftBundle\Entity\Gift
->select('g.id , g.price')
->addSelect('SUM(p.amount) as totalContribute')
->join('g.purchase','p') // pay attention for this line: you specify relation basing on entity property - I assume that is "$purchase" for this example
->leftJoin('p.registry', 'reg') // here you join with \BBB\GiftBundle\Entity\Purchase
->where('reg.couple = :coupleID')
->orderBy('reg.id','DESC')
->setParameter('coupleID', $coupleID);
Please treat this as pseudocode - I didn't check it works but it should like more like this.
One more thing - if your repository method returns object(s) of X entity you should put this method to XRepository.
I'm using the Massive Query method to write a simple join query against an Oracle database. This is my code with the query simplified even further by taking out some columns:
dynamic logTable = new DynamicModel("mydatabase", "table1");
var sb = new StringBuilder();
sb.Append("select CONTACT_ID from table1 inner join table2 on table1.ID = table2.ID ");
sb.Append("where table1.ID=:0");
dynamic dbResult = logTable.Query(sb.ToString(), id);
The following code gives me an error: 'object' does not contain a definition for 'CONTACT_ID'
string id = dbResult.CONTACT_ID.ToString();
If I take the exact query and run it through sqldeveloper, I get back the expected results. If I try to Query through Massive without a join, I get back an object I can work with.
Any ideas?
My mistake! I was expecting my query to return only one record, but forgot that Query returns IEnumerable. Solution is to take First() or loop over the results.