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CRUD is what we often call addition, deletion, query and modification. It is also the most basic operation of the database C: create add R: retrieve find U: update modification D: Delete delete Comment: in SQL - indicates a comment, which needs to be on a single line, or use comment comment. 1, Create Let's create a student table first ...

skiplist is a very useful data structure, which is also common in interviews. Its efficiency is basically equivalent to that of red black tree, and its coding implementation is much simpler than that of red black tree 1. How to implement a dict by yourself Unlike C + +, java and other high-level languages with built-in map, C language does ...

Principle of import module 1. Introduction principle When the code is executed to the import module, the system will automatically enter the specified module and execute all the codes in the module; If the same module is imported multiple times in the same program, the corresponding code will be executed only once. # import test # import tes ...

catalogue preface 1, Log management of MySQL 1. Overview 2. Log classification of MySQL 3. MySQL log on 4. Enter the database to check whether the corresponding log is enabled four point one   Check whether the general query log is enabled four point two   Check whether the binary log is enabled 5. View slow query log relat ...

catalogue preface 1, MySQL incremental backup 1. Concept of incremental backup 2. Advantages and disadvantages of incremental backup 3. Significance of binary log backup 4. Realize incremental backup 2, Incremental recovery 1. Incremental recovery mode 2. Recovery of changed data after loss of full backup 3. Recover all data lost afte ...

1, JDBC introduction JDBC(Java Database Connectivity) is a common interface (a set of API s) independent of a specific database management system and general SQL database access and operation. It defines the standard Java class libraries used to access the database (java.sql,javax.sql). These class libraries can be used to access database ...

preface Every time the data is backed up completely, that is, the whole database, database structure and file structure are backed up. What is saved is the database at the time when the backup is completed. It is the basis of differential backup and incremental backup. The backup and recovery operations of full backup are very simple and ...

Oracle create table Oracle table is the core of Oracle database and the logical basis for storing data. Oracle table is a two-dimensional data structure. The data with column fields and corresponding columns constitute a data storage structure. You can simply look at a two-dimensional table in rows and columns. Columns represent Oracle columns ...

I. overview of RedisTemplate 1.Redis Redis is an open source key value database, which runs in memory and is written in C language. Redis is usually used for enterprise development to implement caching. Similar products include Memcache. Memcached, etc. 2.Jedis Jedis is a Java oriented client officially launched by Redis, which provides man ...

Chapter 56 SQL command INSERT OR UPDATE Add a new row to the table or update an existing row in the table. outline INSERT OR UPDATE [%keyword] [INTO] table SET column = scalar-expression {,column2 = scalar-expression2} ... | [ (column{,column2} ...) ] VALUES (scalar-expression {,scalar-expression2} ...) | ...