Personal summary of the net must face question

1. can you explain the full process of MVC?

All end-user requests are sent to the controller. The controller relies on the request to choose which model to load and attach the model to the corresponding view. The final view attached to the model data is sent to the end user as a response.

2. What do you mean by your understanding of MVC?

MVC is a design pattern is the main idea, is a functional structure of a modular development idea, the purpose is to better manage their own code.

ASP. NET MVC is a kind of UI framework that Microsoft completely reconstructs the ASP. NET WebForm framework, making it easier and clearer to develop Web applications.

3. What is razor in MVC?It is a lightweight view engine. What is 4.LinQ?

LINQ is a programming model for data access that makes. NET language can directly support data query the goal of LINQ is to reduce the complexity of accessing data,

LINQ can access different types of data in a uniform way, can use the data as an object, and better integrate with the programming model

What is an 5.LAMBDA expression?

A lambda expression is an anonymous function, and an anonymous function is a delegate, so a lambda expression is a delegate.

6.EF What is it?

EF is the ORM Framework for object-relational mapping developed by Microsoft on the basis of ADO, with three implementations: Code first,db First,model First, which we use in DB Frist,

The database is designed, and then the code is programmed to interact through the context object. The difference between EF and dapper, EF is a strongly typed ORM framework, dapper is a weakly typed ORM framework

First, Dapper

Question: Describe your understanding of dapper?

Answer: 1, Dapper is a lightweight ORM class, code on a SqlMapper.cs file, compiled only 70k

2 , dapper support multi-database, support sqlserver,mysql,oracle, etc.

3 , dapper syntax is simple, easy to get started

7 , what is a delegate, is an event a delegate?

1. A delegate can substitute a method as a parameter into another method.
2. A delegate can be understood as a reference to a function.
3, the event is a special delegate

Delegate < function return type > < delegate name > (< function parameter >)

What is 8.c# multithreading?

The advantages of Multithreading: You can complete multiple tasks at the same time, you can make the program more responsive, you can save a lot of time for processing tasks, you can stop the task at any time, you can set the priority of each task to optimize program performance.

9.WEBAPI Overview

The Web API is the framework for a Web-based API built on the. NET framework, and the Web API is a programming interface for manipulating systems that can be accessed through standard HTTP methods and headers.

Web API needs to be developed based on. NET 3.5 or later

What is WebService

WebService is a cross-platform, cross-language specification for interactions between different platforms, different language-developed applications, and is a network-based, distributed, modular component that performs specific tasks,

adhere to specific technical specifications.

11. What is a stored procedure? What's the use? What are the advantages? Using what to invoke?

Stored procedures are precompiled, high security, and also greatly improve efficiency, stored procedures can be reused to reduce the workload of database developers, complex logic we can use the stored procedures to complete,

In the stored procedure we can use temporary tables, we can also define variables, splicing SQL statements, call, just execute the name of the stored procedure, passing in the parameters we need to

What is a trigger?

A trigger is a special kind of stored procedure that is executed primarily through event triggering. It can enforce constraints to maintain data integrity and consistency, and can track operations in the database from

without permission to update and change. Can be the level of transport calculation,

There are three common triggers: Apply to insert, Update, Delete event, respectively.

13.SQL Optimized

1. Select the most efficient table name order 2. Avoid using ' * ' 4 in connection order 3.SELECT queries in the WHERE clause. Reduce the number of database accesses 5. Use the Decode function to reduce processing time
6. Replace the HAVING clause with a WHERE clause 7. Reduce queries on tables use the alias of the table 9. Replace in with exists. 10. Replace not in with not exists. 11. Replace the exists with the table connection.
12. Replace the distinct with exists. 13. Improve efficiency with indexes 14. Avoid using calculation 15 on indexed columns. Avoid using is null and is not NULL on indexed columns

What is the role of a transaction?

Things simply are either executed together, or not executed, if there's a mistake in place, all rolled back, not executed

Transaction 4 Large Properties:

1 atomicity (atomicity): A transaction is a complete operation.

2 Consistency (consistency): When a transaction completes, the data must be in a consistent state.

3 Isolation (Isolation): All concurrent transactions that modify data are isolated from each other.

4 Persistence (Durability): After a transaction completes, its effect on the system is permanent.

Statements for managing transactions in T-sql: Start transaction: BEGIN TRANSACTION COMMIT TRANSACTION COMMIT TRANSACTION ROLLBACK TRANSACTION ROLLBACK TRANSACTION

Transaction classification: Explicit transaction: The beginning of a transaction is explicitly specified with BEGIN TRANSACTION.

2 Implicit transactions: When operating in implicit transaction mode, SQL Servler automatically starts a new transaction after committing or rolling back a transaction. Cannot describe the beginning of a transaction, only the transaction must be committed or rolled back.

3 autocommit transaction: The default mode of SQL Server, which treats each individual T-SQL statement as a transaction. If executed successfully, it is automatically committed or rolled back.

What is an AJAX asynchronous call?

It is not necessary to load the entire page of data, only a small portion of data, so that the asynchronous call can be implemented.

15.ORM What is it?

ORM, the Object-relational Mapping (Object relational mapping), is a mapping between a relational database and a business entity object,

In this way, we do not need to deal with complex SQL statements when we operate the business objects, simply manipulate the object's properties and methods.

The ORM methodology is based on three core principles: simple: Modeling data in the most basic form. Communication: The database structure is documented in a language that anyone can understand.

Accuracy: Create a properly standardized structure based on the data model.

16. What is a generic type?

From a programmatic point of view, when defining a class or method, omit the specific type, which is specified by the caller, and the type + generic type composition gets the true type. From the implementation mechanism, generics are the CLR that

The runtime dynamically creates anonymous types based on generic types. From the perspective of OO design, generics embody polymorphism. Generics allow programmers to reuse data structures and algorithms, and adapt to different types,

Enjoy strong type checking and syntax hints during compilation. Some classic FCL provides generic types and interfaces: List<t>, DICTIONARY<T1, t2> This belongs to the multiplexed data structure

Icomparer<t>, ienumerable<t> This belongs to the multiplexing algorithm

What are the value types and reference types in C #, respectively?

Value types: struct (numeric type, bool type, user-defined struct), enum, nullable type. Reference type: array, user-defined class, interface, delegate, object, String.

How to solve high concurrency problems in the project?

Answer: Try to use the cache, including user cache, information cache, etc., spend more memory to do the cache, you can reduce the interaction with the database, improve performance.
Optimizes database query statements.
Optimize the database structure, do more indexing, improve query efficiency.
Statistical functions as far as possible cache, or according to a daily statistical or timing statistics related reports, to avoid the need for statistical functions.
Use static pages wherever possible, reducing the parsing of containers (as much as possible to generate static HTML for dynamic content display).
After solving the above problems, use the server cluster to solve the bottleneck problem of single station.

19. Agile development?

Agile development is a human-centric, iterative, progressive approach to development. It is not a technology, but a way of development, that is, a software development process.

It will guide us to use the prescribed link to complete the development of the project in step.

Because it uses iterative development, the main driving core of this development approach is people.

Please describe the methods used in. NET to pass parameters among several pages, and say their pros and cons.
1, session (ViewState) simple, but easy to lose
2, Application Global
3, the cookie is simple, but may not support, may be forged
4, input type= "hidden" simple, may be forged
5, the URL parameter is simple, displays in the address bar, the length is limited
6, the database is stable, secure, but the performance is relatively weak

21.IOC A container?

The IOC is a design idea, in the previous project, when we need an object, we need a new object, and the IOC design idea is that we will need to inject the object into a container,

"Extension": The IOC and DI IOC are control reversals, Di is dependency injection, the interpretation of control inversion is somewhat ambiguous, and dependency injection is very clear, we will need to inject the object into the container, get the required resources

22.ado.net five big objects?

(1) Connection object
The Connection object is like a war-time communicator, and they need to connect the communication lines between the headquarters and the various combat units before they fight. After that, the acquisition and release of the command will be done by the communication line.
The command here is similar to the server, and the units are similar to each application.
(2) Command object

Execute some simple operation commands, such as adding and deleting, i.e. executing T-SQL statements. The command object has several more important methods, such as the ExecuteNonQuery () method, which performs the delete and change commands, and returns the Shadow
The number of rows that are ringing. There are 2 ways to query: One is the ExecuteReader () method, and a DataReader object is returned. There is also the Executescale () method, which returns the first line column value.

(3) DataAdapter Object

Data adapters, retrieving data from the database, and populating the local data set. At the same time, we can use DataAdapter to update the data back from the dataset to the database. DataAdapter using the main
It is important to have 4 command objects. They were: SelectCommand, InsertCommand, UpdateCommand, DeleteCommand. SelectCommand, primarily retrieving data from a database
The 3 command objects, InsertCommand, UpdateCommand, and DeleteCommand, are primarily responsible for uploading data from a dataset in a local dataset back to the server. Our main use is the former.
The Fill method of the DataAdapter, which is used to populate the dataset with the execution result set of the DataAdapter SelectCommand.

(4) DataReader object

You can use the DataReader object when we only need to read the data sequentially and no other action is required. The DataReader object simply reads the data from the data source one stroke at a time, without any other action
。 Because the DataReader restricts reading only one stroke at a time while reading the data, it can be used to save resources and be very efficient. Besides, because you don't have to pass all the data back,
Therefore, the network load can be reduced. However, when we read the data from a data source, we must remember to always open the database connection.

Second, the DataSet object

The DataSet object can be considered as a database in local memory and can be persisted locally from the data queried in the database. The ability of a DataSet is not just to store multiple table,
You can also get some data table structures such as primary keys through DataAdapter objects, and can record the association between data tables. When we use a dataset to read data, is the database connection
It doesn't matter how close it is. The DataSet object can be said to be a heavyweight object in ADO, and the ability to communicate with the data source is achieved through the bridge of the DataAdapter object.

Personal summary of the net must face question