• Guest officer, here is a reading note of “MySQL Must Know and Know”, please accept it!


    This article has included the 1.1K Star number open source study guide – “Dachang Interview Guide North”, if you want to learn more about Dachang interview-related content and obtain the offline PDF version of “Dachang Interview Guide North”, please scan the two pages below Pay attention to the official account “Dachang Interview” via QR code, […]

  • Programmers pass the test – why are you still using stored procedures?


    stored procedure Stored Procedure (Stored Procedure) is a set of SQL statement sets in order to complete a specific function in a large database system. It is stored in the database and is permanently valid after one compilation. stored procedure with parameters) to execute it. A stored procedure is an important object in the database. […]

  • Use SCOM to monitor SQL server service


    please find “Microsoft SQL Server -> SQL server 2005/8/12/14 -> Database Engines-> Database Engines View. And one you will enable it you can check its data via SQL 2005/8/12/14 DB Engine > Entity Health > Performance > Blocking Sessions

  • SQLServer row data is converted to column data


    Preparation create table use [test1] go create table [dbo].[student]( [id] [int] identity(1,1) not null, [name] [nvarchar](50) null, [project] [nvarchar](50) null, [score] [int] null, constraint [pk_student] primary key clustered ( [id] asc )with (pad_index = off, statistics_norecompute = off, ignore_dup_key = off, allow_row_locks = on, allow_page_locks = on) on [primary] ) on [primary] go insert data […]

  • DBASK Q&A Collection Issue 5


    introductionRecently, we have newly associated public accounts in the data field such as Hanfeng Channel, Internet Scouting, Database SQL, SQL Database Development, Cross-Border Architect, Shi Shan’s Architecture Notes, etc. in the DBASK applet. The aggregated updates are displayed, and everyone is welcome to read and share. Questions and AnswersNext, we share the problems and diagnosis […]

  • Improve the sql level, record 50 classic sql questions [including table building sql, answer sql, highly recommended for those who want to improve sql level]


    I left school in June this year, and I will summarize some things every once in a whileI firmly believe that time will witness the pace of hard workThis article is hereby written to review the 50 most popular sqls on the Internet. The ideas and sqls in them are all records on my way […]

  • Entity Framework one-to-one relationship mapping


    One-to-one relationship is a very complex relationship in Entity Framework, involvingHasOptional 、WithRequired 、 WithOptionalPrincipal 、 WithOptionalDependent. In this article, we will explain in detail how to use them. Let’s take members and orders as an example. A member may or may not have an order, but an order definitely belongs to a member. Let’s first […]

  • Entity Framework many-to-many mapping


    In the previous article, we explained the one-to-many relationship mapping in EF. In this article, we explained the many-to-many (Many-to-Many Relationship) relationship mapping in EF. In this article, we also use a simple example to explain the many-to-many relationship mapping. Zero, automatic generation of relational tables Story: In a student course selection system, there are […]

  • Entity Framework entity state


    Starting today, we begin to explain the entity state and data operations in EF. This article first explains the entity state.Through the previous study, we know that EF is responsible for tracking the state of the entity through the upper and lower bits. The location of the entity state is in the namespaceSystem.Dat.EntityinnerEntityState, there are […]

  • Entity Framework little knowledge (5)


    existMany-to-many relationship mappingThe middle association table is automatically generated by EF. But sometimes we need to display the definition association table. We can define it in the following steps (continue to use the many-to-many relationship mapping article to starve the code): Define the association table class: public class StudentCourses : BaseEntity { public int StudentId […]

  • Entity Framework Private Property Mapping


    This article is purely for self-entertainment, because the possibility of using private attribute mapping in actual development is almost zero. The default mapping in EF is to havepublicModifier properties, but if theinternal 、 privateandprotectedHow to map the modified attributes into the database? Let’s explain them separately. zero, internal attribute mapping Let’s create the code entity […]

  • Entity Framework Inheritance Mapping


    Inheritance is often used in object-oriented development, but the SQL Server database does not have inheritance, so what can I do? We can use the following three methods: TPH (Table per Hierachy): Denormalize the SQL schema to represent polymorphism, and use discriminant columns to distinguish types; TPT (Table per Type): Use foreign keys to represent […]