Principle and Implementation interpreter mode of Atitit. linq java, atitit. linq Interpreter
Principles and implementation interpreter mode of Atitit. linq java
1. Implementation of Linq from where 1
2. Where expr Implementation 1
3. A variation of Attilax 2
4. interpreter mode structure 2
5. Code3
5.1. EqExpression3
Due to the limited time yesterday, there are still some follow-up. To maintain the habit of summing up and writing blogs on a daily basis, I have finished the basics of the LinQ technology today, the rest is to see how we can make the best use of it.
Today's highlights:
1. Concurrent management mechanism of LinQ to Entity
2. Implementation of LinQ to DataSet
This article is organized from the msdn
I. Concepts of LINQ:LINQ is short for Language Integrated Query (Language integration query), which is integrated in. netProgramming LanguageThis allows the query expression to get a good syntax check during compilation, rich metadata, and advantages of smart sensing for other strong languages. net Framework Version 3.5 is a groundbreaking innovation that builds a bridge between the object field and the data field.
Ii. Background of the emergence of LI
Recently, an article published by Elisa Flasko on MSDN compares the applicable scenarios of LINQ to SQL and LINQ to Entities:
Introducing LINQ to Relational Data
Http://msdn2.microsoft.com/en-us/library/cc161164.aspx
The author points out that the main application scenarios of LINQ to SQL are the rapid development of M
Recently, an article published by ELISA flasko on msdn compares the applicable scenarios of LINQ to SQL and LINQ to entities:Introducing LINQ to Relational DataHttp://msdn2.microsoft.com/en-us/library/cc161164.aspx
The author points out that the main application scenarios of LINQ to SQL are the rapid development of Mic
We know that LINQ to Sharepoint is actually converted into calm for access to SharePoint. So how can we know what the calm statement we write is eventually converted.We can use the following methods to achieve our goal.
1. First, create a new class named camldebug in our SharePoint project ,:
Calmdebug. CSCodeAs follows:
Using System;
Using System. Collections. Generic;
Using System. LINQ;
Us
C # conversion between Dto Linq Expression and Model Linq Expression in the database in ORM,
Today, I saw a question in Baidu zhixing. After studying it for a while, I answered:
Http://zhidao.baidu.com/question/920461189016484459.html
How to convert a dto linq expression to a database object linq expression. It is feas
1. Single Condition queryvar expr = context. "LINQ to SQL");SELECT [Extent1].[ProductID] as [ProductID], [Extent1].[CategoryID] as [CategoryID], [Extent1].[ProductName] as [ProductName], [Extent1].[UnitPrice] as [UnitPrice], [Extent1].[discontinued] as [discontinued] from [dbo].[Product] as [Extent1] WHEREN'LINQ to SQL' = [Extent1].[ProductName]2. Combination criteria Queryvar expr = context. Products "
ArticleDirectory
1. Get start
2. latency mechanism (deferred/lazy execution)
3. subquery)
Language Integrated Query is a group of technical names that allow us to write type-safe query statements to query local objects or remote data sets. The premise of using LINQ is that the collection you need to query implements the ienumerable ProgramExtend the implementation of LINQ, for example,
ArticleDirectory
Overview of the linq to XML class
LINQ to XML learning-2. Overview of LINQ to XML programming overview of the linq to XML class overview of the xattribute class
Xattribute indicates an XML Attribute. Xcdata class
Xcdata indicates a CDATA text node. Xcomment class
Xcomment indicates an X
Hi: The following is a LINQ to JS share, if there is a coincidence is purely coincidental(function () {Array.prototype.first = function (predicate, def) {var l = this.length; if (!predicate) return l? This[0]: def = = null? Null:def; for (var i = 0; i How to use: List.first (function (t) {return T.value.trim () = = City.trim ();}); JS simulation expands C # LINQ expressions to share
Label: style blog color Io AR for strong SP Div
Grouping refers to grouping values or elements in a sequence based on a specific value. LINQ only contains one grouping OPERATOR: groupby.
Groupby
1>. Prototype Definition
Public static iqueryable
2>. Example
VaR expr = from P in context. products Group P by P. categoryid; foreach (VAR item in expr) {foreach (var p in item) {console. writeline (P. productname );}}
VaR expr = context. Cities. grou
This article mainly describes attributes-based Linq ing of Linq to SQL. That is, ing database, ing table, ing column, ing relationship, ing stored procedure,
Ing function. However, there are three ways to create such mappings: ORD, SQLMetal, and manual code.
Create.
First, let's understand how to manually create property ing so that you can understand the code generated based on the tool. Their differenc
Combination of Linq groups and linq groups
There is a List, which requires grouping by date and combining the data of the same day with the implementation of Linq.
namespace ConsoleApplication1{ class Program { static void Main(string[] args) { List
We can see that the data items are grouped by date, and the data items of other a
And then, in this section, I'm going to lead you through the rest of the LINQ syntax. OK, no more nonsense, get to the point.
1, Cast, oftype operator
Cast and OfType: are used to convert a collection object of type IEnumerable to a collection object of type ienumerable
Here's an example from the previous section: (This example is referenced from Rookie_j blog)
Create a new ArrayList object first
ArrayList ArrayList = new ArrayList ()
{
New Person ()
We use a database of hotel management systems as an exampleTable structure is simple: guestinfo (guest information table), Room (rooms table), Roomtype (room type table), Hotelinfo (monthly earnings information)As a whole, there is a foreign key to the room type ID, and a foreign key for the ID of the room in the guest table. Monthly earnings information regardless of firstPreparation: New Project LINQ_CH4 console program, new DB folderRight-click the DB folder, add → new itemSelect the
[ProductID], [Extent1].[ProductID] as [ProductID1], [Extent1].[ProductName] as [ProductName] from [dbo].[Product] as [Extent1] UNION All SELECT [Extent2].[CategoryID] as [CategoryID], [Extent2].[CategoryID] as [CategoryID1], [Extent2].[CategoryName] as [CategoryName] from [dbo].[Category] as [Extent2]) as [UnionAll1]2. Unionvar expr = context. Products = p.productname) . Union ( context. Categories = c.categor
result;}
C # For example, how to calculate the data table at a specific point during a long period of time. In SQL, describe what you want ". In C #, describe how to get the expected result. In SQL, selecting the most efficient algorithm to perform the "how" Operation (more explicit in C #) is to check the role of the engine. This is because the SQL query engine has more quota space than the limit on the C # compiler.Note:The functions of the previous C # example are as follows. NET 2.0 can be
1. Anonymous typeBy defining an anonymous type with the keyword VAR, the compiler emits a strong type based on the value of the expression on the right side of the operator.Some basic rules to follow when using anonymous types:◊ An anonymous type must have an initialization value, and the value cannot be null (NULL), because the type is inferred from the initializer;◊ Anonymous types can be used for simple types, or for complex types. When defining a simple type, it is of little value. Compound
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.