dive into linq

dive into linqivan towlsonmindscape

imagine there’s no sql

three worlds

ObjectsXMLRelational

ObjectsXMLRelationalWeb ServicesNoSQL

ObjectsXMLRelationalWeb ServicesNoSQLWMIEmail

ObjectsXMLRelationalWeb ServicesNoSQLWMIEmail

three worlds…for large values of three

“queries should just ‘be there,’like for loops”

anders hejlsberg

linqlanguage integrated query

language syntax

standard query operators

query implementation framework

language syntax

standard query operators

query implementation framework

putting the lin into linq

LINQ…

…to Objects

IEnumerable

…to XML

XDocumentfamily

…to SQL

Table<T>SQL Server

language syntax

standard query operators

query implementation framework

language syntax

standard query operators

query implementation framework

when syntax runs out

everything is query operators

language syntax

standard query operators

query implementation framework

language syntax

standard query operators

query implementation framework

I plan to query overONE… MILLION… OBJECTS!

what is the meaning ofx.Select(…)?

what is the meaning ofx.Select(…)?

IEnumerable<T> x;

IQueryable<T> x;

what is the meaning ofx.Select(…)?

IEnumerable<T> x;Enumerable.Select(x, …)

IQueryable<T> x;Queryable.Select(x, …)

IQueryable<T> x;Queryable.Select(x, …)

Table<T> x;Queryable.Select(x, …)

Queryable

IQueryProvider

SQL Entities LightSpeed NH ….

Queryable

IQueryProvider

SQL Entities LightSpeed NH ….

Queryable

IQueryProvider

SQL Entities LightSpeed NH ….

Expression tree

IQueryable

.Provider

Native query

xs.Where(…).Select(…) Table<X>

SELECT …FROM X

WHERE …

linq to sql

xs.Where(…)

.Select(…)Query<X> Find<X>(qx)

linq to lightspeed

xs.Where(…).Select(…) WmiQuery<X> WqlObjectQuer

y

linq to wmi

Expression tree

IQueryable

.Provider

Native query

language syntax

standard query operators

query implementation framework

language syntax

standard query operators

query implementation framework

thinking in linq

what is a query?

what is a query?extract, transform and load

what is a query?‘what am i interested in’

i am interested in…drag and drop

i am interested in…a mouse down

followed by mouse movesuntil i get a mouse up

ObjectsXMLRelationalalmostanythingactually…

ObjectsXMLRelationalalmostanythingactually…

“queries should just ‘be there,’like for loops”

anders hejlsberg

thanks!

ivan@mindscape.co.nzwww.mindscape.co.nz

ivan@hestia.cchestia.typepad.com/flatlander