Programmer Group

From the beginning of database creation, table creation, column creation, then to the commonly used EXISTS function, SELECT complex query, fuzzy query LIKE, view creation and other in-depth study. In order to deepen the impression of the words, all in the DOS demonstration! Create databases, tables <span style="font-size:14px;">creat ...

I. File Storage Without any formatting of the stored content, it is suitable for storing simple text data or binary data. 1. Store 5 pieces of music: Gets the FileOutputStream object, which is obtained through the openFileOutput() method provided by the Context class Get the OutputStreamWriter object, and pass in the FileOutputStream object ...

MongoDB Index Why use index? Assuming there is a book, you want to see what Chapter 6, Section 6, says, and what you will do, the average person must go to the catalogue, find the corresponding pages of this section, and then turn to this page. This is the catalog index, which helps readers quickly find the chapters they want. In databases, w ...

For DBA, monitoring disk usage is a necessary task. There is no easy way to obtain disk space usage information. Here's a summary of the scripts saved over the years: The most commonly used way to view disk free space, which is a must-remember entry to DBA: -- View Disk Available Space EXEC master.dbo.xp_fixeddrives The xp_fixeddrives m ...

This paper implements a GridView with ASP.NET MVC 5. Its functions include paging, filtering, sorting, asynchronous execution of AJAX, and also support Responsive Web Design in appearance. The execution screen is shown in Fig. 1 below.ASP.NET MVC implements GridView and paging in many ways. This article refers to several articles of Code Projec ...

Step by step build a simple MVC website - BooksStore brief introduction The main functions and knowledge points are as follows: Classification, product browsing, shopping cart, settlement, CRUD management, paging and unit testing. [Remarks] The project is developed using VS2015 + C.   I. Creating Project Architecture 1. Create a new solu ...

EF Core uses Linq to query data. Basic Query Microsoft provides more than 100 examples to demonstrate queries at https://code.msdn.microsoft.com/101-LINQ-Samples-3fb9811b We can make a simple query through the following code: //Get all the data var blogs = context.Blogs.ToList(); //Getting a single entity var blog = context.Blogs.Single(b =&gt ...

This paper introduces how Python 3 uses PyMySQL to connect database, and implements simple addition, deletion and modification. What is PyMySQL? PyMySQL is a library for connecting MySQL servers in Python 3.x, and mysqldb is used in Python 2.x. PyMySQL installation Before using PyMySQL, we need to make sure that PyMySQL is installed. PyMySQL Do ...

1. Introduction to PLSQL Oracle database extends SQL, and then adds some programming language features, which can control the execution process of SQL, and then realize some complex business functions. 1.1 Composition of PLSQL Component declare - It's the declaration part. begin - yes plsql ...

Both the Date and Calendar classes are classes about dates, both in the java.util package and require import when used. Date Objects of the java.util.Date class are used to represent time and date. The most frequently used object is to get the current date and time of the system, accurate to milliseconds. There are two Date classes in Java, an ...