How to join below two tables using gosu .. This is from Contact Manager (GW Training App)
1 ABContact
2 BankAccount
Below SQL can be used to find all account hold by one particluar contact
select b.accountnumber from ABContact a, BankAccount b where
a.id=b.contactid and a.id='123'
Please write the same query in Gosu
Query is like this
uses gw.api.database.Query
var account: BankAccount
var query = Query.make(ABContact).join("ID", BankAccount, "Contact").compare(BankAccount#ID, Equals, account.ID)
Related
Cassandra support updating specific value in Collection by syntax
ALTER TABLE users ADD todo map<timestamp, text>
UPDATE users SET todo['2012-10-2 12:00'] = 'throw my precious into mount doom'
WHERE user_id = 'frodo';
http://www.datastax.com/documentation/cql/3.0/cql/cql_using/use_map_t.html
Did not see any example of using QueryBuilder to update specific row in Map. How it can be done?
I think you have several options.
1/ Build your own query based on the CQL one.
Example: Consider that you have a table named Interactions and in your schema a column of type named 'attributes'.
String update ="UPDATE demo.Interactions SET attributes=attributes + {'i':'j'} where id='ff';
SimpleStatement statement = new SimpleStatement(update);
session.execute(statement);
2/ Use Java API.
Java API is not that documented indeed.
Let's take an example
a- Create an update object using queryBuilder
Update update = QueryBuilder.update(keyspace, tableName);
b- Then populate with 'put' or 'putAll' functions. put/putAll will add/update content
update.with(QueryBuilder.putAll(key, map));
To remove a key, set the content of a key to null, like:
for (Object item : map.keySet()) {
update.with(
QueryBuilder.put(columName, item, null)
);
}
Then execute the query.
Following methods are available for different types:
LIST:
QueryBuilder.appendAll(...)
QueryBuilder.discardAll(...)
SET:
QueryBuilder.addAll(...)
QueryBuilder.removeAll(...)
MAP:
QueryBuilder.putAll(...)
QueryBuilder.put(...)
The list is not exhautive.
Have a look in QueryBuilder class if you do not find what you are looking for.
Best regards and best luck with Cassandra.
I am using lightswitch and i have to join 3 tables in my query. Table A join Table B join table C where tableC.id == 10
partial void Query2_PreprocessQuery(int? dept, ref IQueryable query)
{
query = query.Join(Employee_Personal_Infoes, b => b.Employee_Personal_Info1.Emp_id, (b));
}
First off, if you add relationships between your tables, you shouldn't ever need to do manual joins. You would then just use the navigation properties that get created when you add the relationships.
Second, you can't change the shape of the entity in a query, or return a set of different entities. If your query is based say on a Customer entity, you can't return a query of CustomerAdresses, or a Client entity from that query. The query can only return a filtered set of the same entity that the query is based on.
Does that make sense?
I have 2 entities namely Product and Transaction and these 2 entities are link via a Many to Many relationship. I have the below in my transaction entity.
#ManyToMany(cascade={CascadeType.ALL})
#JoinTable(name="Transaction_Product")
When I run my project, there will be 3 tables tables created in my database and they are Transaction, Product and Transaction_Product respectively. The Transaction_Product is automatically generated when I run my project.
I am able to get items from my transaction table via this query below.
Query q = em.createQuery("SELECT t FROM Transaction t WHERE t.fulfillStatus = 0");
My question is, how do I get items from the Transaction_Product table?
I tried something like the query below and it did not work.
Query q = em.createQuery("SELECT bt FROM Transaction_Product bt WHERE bt.ProductID = 1);
Any help please? :)
checking if there are transactions with specifyed product u can use :
Query q = em.createQuery("SELECT t FROM Transaction t join t.products p WHERE p.id = :id");
Assuming that Transaction class has field :
#ManyToMany(cascade={CascadeType.ALL})
#JoinTable(name="Transaction_Product")
private Set<Product> products;
I have 2 tables.
Users - have userID, userMainGroup and userMinorGroup
Tasks - TaskId, UserId
My goal is:
I have current CurrentuserId and i want to show him all the tasks that were created by users from the same MainGroup as he.
In SQL i would write:
Select *
From Tasks Left join Users on tasks.Id=users.id
Where users.MainGroup=CurrentuserMainGroup; (var)
How do i do it using entity framework?
I understood that to make a join i need to write something like:
var tasks = from t in db.tasks
from u in db.users
where t.Id=u.Id
select new {t.Id, t.name....}
but where do i put the condition Where on the MainGroup?
you can try like this
var data= (from con in db.tasks
let UserMainGroup = db.users.where(x=>x.id==con.id).FirstOrDefault()
where UserMainGroup.MainGroup=CurrentuserMainGroup
select new {
ID=con.id,
Name=con.name
}).ToList();
i think this will help you.......
It is recommended that you use navigation properties in stead of manually coded joins:
from t in db.Tasks
where t.User.MainGroup == currentuserMainGroup
select new {t.Id, t.name.... , t.User.Name, ... }
Hi is there an easy way to get the values of a foreign key, without writing sql queries.
I generated the code with the help of my mssql database (ADO.NET).
Here's an example for clarification
order table:
id customer_fk
1 100
2 105
customer table:
id name
100 Walter
105 White
view:
#model ...order
...
#customer_fk
#customer_fk delivers eg. "100" instead of "Walter"
Not sure if you are required to use ADO.NET, but to accomplish what you want, without writing sql, you'll need to use some kind of ORM, such as EntityFramework.
You will need to write LINQ, which generates SQL and since EF will know about the relationship between the two tables, you will have access to the "name" property in the customer table.
Linq to SQL might be a good option, since you're using MS SQL. Just add the DataContext item to your project, and drag/drop the tables from your server. Then you should be able to write something like:
public ActionResult Order(int orderId)
{
using (MyDataContext context = new MyDataContext())
{
var loadOptions = new LoadOptions();
loadOptions.LoadWith<order>(o => o.customer);
context.LoadOptions = loadOptions;
var theOrder = context.orders.Where(order => order.id == orderId).FirstOrDefault();
return View(theOrder);
}
}
But if you're already using ADO.Net, maybe just write the query? It's not that difficult:
SELECT order.*, customer.name
FROM order INNER JOIN customer ON order.customer_fd = customer.id
If you're doing this in Entity Framework (or some other similar ORM), you can write a LINQ query that joins to your foreign key table:
var customerOrders =
from o in context.Orders
join c in context.Customers on o.customer_fk equals c.ID
select new { OrderID = o.ID, CustomerName = c.Name };