Part of this article is organized from MSDN
First, the Concept of LINQ:
LINQ is the abbreviation for Language Integrated query (language integration queries), which is integrated in the. NET programming language, which makes query expressions good at compile-time syntax checking, rich metadata, IntelliSense, and other strongly typed languages. Linq is a groundbreaking innovation in
Just a little bit of Linq was attracted by it, and I suddenly came up with the idea of learning and using it in one breath. So I posted a video on the ASP. NET official website. I am not very good at English, but I can understand how to use it. Below I wrote a little bit of fur I learned. It is a learning record.
First, I use Visual Studio 2008 development tools and SQL Server data sources, which are writte
name and its corresponding role name. Right-click the solution-add-new folder (ViewModel), then right-ViewModel the folder--add--class to create a new Userrole class, and add the following entities:Namespace Mvcdemo.viewmodels{public class Userrole{public string UserName {get; set;}public string Userrole {get; set;}}}Right-click the Controllers folder to add a control class that inherits from the Controller classAdd the following code (federated Query
A detailed explanation of the Double quotation marks required for table names and Field Names during oracle SQL statement Query
As a beginner in oracle, I believe everyone will encounter this problem,
It is clear that navicat created a table visually, but it cannot be found! Why?
Select * from user;
However, if we add double quotation marks to the user, it will be different!
Select * from "user ";
However,
SQL random Query
SQL Server:
Select Top N * from Table order by newid ()
The newid () function creates a unique value of the uniqueidentifier type. The preceding statement reads N records randomly from the table.
MySQL: Select * from Table order by rand () limit 10
STR converts a number to a string for comparison.
select ( case STR ( 100 , 4 , 2
What if we want to insert multiple lines of records? You might want to run the INSERT statement multiple times, just like the following PHP code example:INSERT into Tbl_name (col1,col2) VALUES (.);What if we want to insert multiple lines of records? You might want to run the INSERT statement multiple times, just like the following. NET code example:New StringBuilder (); Strsql.append ("INSERT into Tbl_name (col1,col2) VALUES (15,16); " ); Strsql.append ("INSERT into Tbl_nam
Introduction
Recently in the modification of data on the line, you need to now continue to back up the modified data, but the online customer's server is not directly connected, but through a bastion machine, which means that we can not directly connect to MySQL through the visual client, so all operations are required through the SQL statement, Let's take a look at the exported
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