Tag：Press
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Time：2021-11-30
Why? Special €/ h2> What is the power of the tank? React component/ li> Using typescript, you can provide the adjusted type of fixed files/ li> This is the hospital support/ li> For the assembly, set the pressure/ li> What’s wrong? API and scope/ li> Raccoon Н “80 KB”/ li> SupportHLSWhat? Code >. M3u8 (all, […]
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Time：2021-10-14
1. Use Ali’s fastjason 1.1 project pom.xml dependency <dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>1.2.58</version> </dependency> public static void main(String[] args) { String jsonString = “{\”_index\”:\”book_shop\”,\”_type\”:\”it_book\”,\”_id\”:\”1\”,\”_score\”:1.0,” + “\”_ Source \ “: {\” name \ “: \” Java programming ideas (4th Edition) \ “, \” author \ “: \” [US] Bruce Eckel \ “, \” category \ “: \” […]
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Time：2021-1-8
1Introduction to fields and field parameters class Book(models.Model): #If you don’t write an ID, it will default to an ID and add it automatically #primary_ Key = true indicates that the field is a primary key, and only one primary key can be used in a table # id = models.AutoField(primary_key=True) #Varchar type, length, #Field […]
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Time：2021-1-6
1Model creation of multi table operation 1. Book list, author list, author detail list, publishing list, (the third intermediate table) 2. Author and author details: it’s one-to-one. You can write the associated field on either side Books and publishers: one to many. Once the one to many relationship is established, the related fields are written […]
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Time：2021-1-4
1、 Object based cross table query (forward and backward query) #There are two ways to query across tables -Object based cross table query: subquery -Cross table query based on double underscores: association query, join table query #Object based cross table query -Query the city of the book publishing house whose primary key is 1 #Object […]
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Time：2020-12-22
Many people want to write a book and summarize it as a stage of their career. However, the standard of publishing a paper book is usually very high, the process is very long, and the material return may be very low. If there is no deep feelings, extraordinary will, or improper method, it is easy […]
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Time：2020-4-3
There is a long story in this book, and today it is the end of a dream. It has been two years since the book was reviewed, published in English and translated into Chinese. This is a memorable book. The English title of the book is learning Internet of things, and the Chinese title of […]
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Time：2020-4-1
Knowledge points △ reasons for using database 1 complexity of file operation2 synchronization3 concurrent processing4 safety △ database system (DBS)Database (DB) + database management system (DBS) + database application + Database Administrator (BDA) + end user △ database management system dBmNetwork application serverWe are going to use data from the server – we need to […]
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Time：2020-3-28
Oracle view In project development, multi table query is sometimes used. There are many methods, such as association, such as view, but for query, view query is the fastest. If you have a lot of field information in your database, you need to query the whole table, such as two table query. We can extract […]
