{"id":5663,"date":"2007-07-26T13:02:00","date_gmt":"2007-07-26T13:02:00","guid":{"rendered":"https:\/\/blogs.msdn.microsoft.com\/vbteam\/2007\/07\/26\/lambdas-and-take-while-and-group-by-oh-my\/"},"modified":"2024-07-05T14:42:47","modified_gmt":"2024-07-05T21:42:47","slug":"lambdas-and-take-while-and-group-by-oh-my","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/vbteam\/lambdas-and-take-while-and-group-by-oh-my\/","title":{"rendered":"Lambdas, and Take While, and Group By, Oh My!"},"content":{"rendered":"

Hooray! <\/font>Visual Basic 2008 Beta2<\/font><\/a> has been released to the wild today to return to its natural habitat \u2013 the desktops of our beloved customers. (Please note our smiling GPM’s face on that landing page — he’s so <\/strong>happy the Beta is done.)<\/font><\/p>\n

What\u2019s inside? So much that there might be more<\/i> new features than we released in Beta1, but who\u2019s counting? Here\u2019s a laundry list that\u2019s specific to the VB language that\u2019s new <\/i>for Beta2:<\/font><\/p>\n

\u00b7<\/font>         <\/span><\/span><\/span>Query operators<\/font><\/p>\n

o<\/font>   <\/span><\/span><\/span>Group By, Group Join, Join, Take [While], Skip [While], Aggregate, Count, Sum, Min, Max, Average, From <\/font>\u00e0<\/span><\/span> Let<\/font><\/font><\/p>\n

\u00b7<\/font>         <\/span><\/span><\/span>Nullable support<\/font><\/p>\n

\u00b7<\/font>         <\/span><\/span><\/span>Lambda Expressions (aka Inline Functions)<\/font><\/p>\n

\u00b7<\/font>         <\/span><\/span><\/span>Partial Methods \u2013 <\/font>ScottGu<\/font><\/a> mentioned this the other day & <\/font>ScottWis<\/font><\/a> posted a couple weeks back<\/font><\/p>\n

\u00b7<\/font>         <\/span><\/span><\/span>Anonymous Types w\/Keys \u2013 Which <\/font>PaulV<\/font><\/a> has already discussed<\/font><\/p>\n

Here are a bunch of queries you can now write with VB!<\/font><\/p>\n

\n

‘ Find suppliers in the same city as customers<\/span><\/p>\n

From<\/span> cust In<\/span> db.Customers _<\/span><\/p>\n

Join<\/span> sup In<\/span> db.Suppliers _<\/span><\/p>\n

On<\/span> cust.City Equals<\/span> sup.City _<\/span><\/p>\n

Select<\/span> cust.CompanyName, sup.ContactName, cust.City<\/span><\/p>\n

 <\/span><\/p>\n

‘ Find suppliers in the same city, with the same postalcode as customers<\/span><\/p>\n

From<\/span> cust In<\/span> db.Customers _<\/span><\/p>\n

Join<\/span> sup In<\/span> db.Suppliers _<\/span><\/p>\n

On<\/span> cust.City Equals<\/span> sup.City And<\/span> cust.PostalCode Equals<\/span> sup.PostalCode<\/span><\/p>\n

Select<\/span> cust.CompanyName, sup.ContactName, cust.City<\/span><\/p>\n

‘ Find the average unit price and count for products by category<\/span><\/p>\n

From<\/span> prod In<\/span> db.Products _<\/span><\/p>\n

Group<\/span> By<\/span> prod.CategoryID _<\/span><\/p>\n

Into<\/span> Average(prod.UnitPrice), Count()<\/span><\/span><\/p>\n

 <\/font><\/p>\n

‘ For each customer find the group of the suppliers in the same country<\/span><\/p>\n

From<\/span> cust In<\/span> db.Customers _<\/span><\/p>\n

Group<\/span> Join<\/span> sup In<\/span> db.Suppliers _<\/span><\/p>\n

On<\/span> cust.Country Equals<\/span> sup.Country _<\/span><\/p>\n

Into<\/span> SuppliersInCountry = Group<\/span> _<\/span><\/p>\n

Select<\/span> cust.CompanyName, SuppliersInCountry<\/span><\/p>\n

‘ For each customer, the count of the number of suppliers in the same country<\/span><\/p>\n

From<\/span> cust In<\/span> db.Customers _<\/span><\/p>\n

Group<\/span> Join<\/span> sup In<\/span> db.Suppliers _<\/span><\/p>\n

On<\/span> cust.Country Equals<\/span> sup.Country _<\/span><\/p>\n

Into<\/span> NumSuppliers = Count() _<\/span><\/p>\n

Select<\/span> cust.CompanyName, NumSuppliers<\/span><\/span><\/p>\n

 <\/font><\/p>\n

‘ Avg price, avg # in stock, and max on order for non-discontinued products<\/span><\/p>\n

Aggregate<\/span> prod In<\/span> db.Products _<\/span><\/p>\n

Where<\/span> Not<\/span> prod.Discontinued _<\/span><\/p>\n

Into<\/span> AvgPrice = Average(prod.UnitPrice), _<\/span><\/p>\n

     <\/span>AvgInStock = Average(prod.UnitsInStock), _<\/span><\/p>\n

     <\/span>MaxOnOrder = Max(prod.UnitsOnOrder)<\/span><\/p>\n

‘ Find orderID, OrderDate, and OrderTotal for each order<\/span><\/p>\n

From<\/span> order In<\/span> db.Orders _<\/span><\/p>\n

Where<\/span> order.OrderDate > #7\/22\/1996# _<\/span><\/p>\n

Aggregate<\/span> ordDet In<\/span> order.Order_Details _<\/span><\/p>\n

Into<\/span> OrderTotal = _<\/span><\/p>\n

       <\/span>Sum(ordDet.UnitPrice *ordDet.Quantity * (1 – ordDet.Discount))<\/span><\/p>\n

Select<\/span> order.OrderID, order.OrderDate, OrderTotal<\/span><\/p>\n

 <\/span><\/p>\n

‘ Fill a dictionary with the customers by CompanyName<\/span><\/p>\n

db.Customers.ToDictionary(Function<\/span>(cust As<\/span> Customer) cust.CompanyName)<\/span><\/span><\/p>\n<\/div>\n

 <\/font><\/p>\n

In addition to all the new language support, we now have keyword Intellisense (finally!)<\/font><\/p>\n

\"Keyword<\/p>\n

We have XML Intellisense<\/a>! What?? That\u2019s right.<\/font><\/p>\n

\"XML<\/p>\n

And we\u2019ve done some major performance improvements for the background compiler \u2013 let us know if you experience any sluggishness for this Beta.  (BTW, you should check out Scott’s post<\/a> on Beta2 to avoid some problems with AJAX extensions if you’re installing to a machine that has had previous versions of Orcas installed on it or has VS 2005 side by side.) <\/font><\/font><\/p>\n

Also, don\u2019t forget to look for other exciting features around the product that pertain to VB and\/or LINQ. For example, Linq to SQL now supports the <\/font>Like<\/span> operator! There\u2019s also a new <\/font>ASP:LinqDataSource<\/font><\/a> control. <\/font><\/p>\n

<\/font> <\/p>\n

So, <\/font>get the bits<\/font><\/a> while they\u2019re hot!<\/font><\/p>\n

<\/font> <\/p>\n

-Amanda<\/font><\/p>\n","protected":false},"excerpt":{"rendered":"

Hooray! Visual Basic 2008 Beta2 has been released to the wild today to return to its natural habitat \u2013 the desktops of our beloved customers. (Please note our smiling GPM’s face on that landing page — he’s so happy the Beta is done.) What\u2019s inside? So much that there might be more new features than […]<\/p>\n","protected":false},"author":260,"featured_media":8818,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[192,195],"tags":[28,74,94,117,122,134,166],"class_list":["post-5663","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-featured","category-visual-basic","tag-amanda-silver","tag-ide","tag-linqvb9","tag-orcas","tag-paul-vick","tag-scott-wisniewski","tag-vb2008"],"acf":[],"blog_post_summary":"

Hooray! Visual Basic 2008 Beta2 has been released to the wild today to return to its natural habitat \u2013 the desktops of our beloved customers. (Please note our smiling GPM’s face on that landing page — he’s so happy the Beta is done.) What\u2019s inside? So much that there might be more new features than […]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/vbteam\/wp-json\/wp\/v2\/posts\/5663","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/vbteam\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/vbteam\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/vbteam\/wp-json\/wp\/v2\/users\/260"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/vbteam\/wp-json\/wp\/v2\/comments?post=5663"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/vbteam\/wp-json\/wp\/v2\/posts\/5663\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/vbteam\/wp-json\/wp\/v2\/media\/8818"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/vbteam\/wp-json\/wp\/v2\/media?parent=5663"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/vbteam\/wp-json\/wp\/v2\/categories?post=5663"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/vbteam\/wp-json\/wp\/v2\/tags?post=5663"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}