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Introduction to JDBC Java Database Connectivity (JDBC) is an application interface in the Java language that specifies how client programs access the database, providing methods such as querying and updating data in the database. Database Driver What is a database driver? Similar to sound card driver, graphics card driver Our programs ar ...

What is a bloom filter Bloom Filter was proposed by a young man named bloom in 1970. It has been 50 years since then. It is actually a very long binary vector and a series of random mapping functions. Everyone should know that the stored data is either 0 or 1, and the default is 0. It is mainly used to judge whether an element is in a set. 0 ...

In the previous article, we gave an overview of database knowledge:< Database overview >, this paper introduces some basic and commonly used SQLite database knowledge. SQLite Foundation SQL basic syntax insert INSERT INTO Table name (Column name 1,...) VALUES (Column 1 value,...); modify UPDATE Table name SET Column name 1= Colum ...

Guide: many friends analyze data for two minutes and run for two hours? In the process of using SQL, we should not only pay attention to the data results, but also pay attention to the execution efficiency of SQL statements. This article involves three parts with a long length. It is suggested to read it after collection: SQL introductio ...

mysql5.7 master-slave synchronization, mycat2 configuration, read-write separation (windows) This article is referenced and reproduced from the article MySQL5. Master slave configuration,mycat2 fast build,mycat2 read write separation configuration , only used to record your learning process 1, Mysql5 7 configure master-slave synchronization ...

Java implements password adding random salt for MD5 digest encryption (2021 / 05 / 11) 1. General In daily development, we often face the problem of saving the user password. We must not store the password in plaintext to the database. We can use hash digest algorithm to encrypt the password and then save it to the database. Hash digest ...

In the process of online MySQL installation, since centos7 was used for the first time, it took a long time to record the successful configuration method. Modify yum source Enter the local machine to modify the yum configuration file Enter yum.com repos. D directory cd /etc/yum.repos.d/ Add the existing Yum source: / etc / yum repos ...

[tcallusdb knowledge base] restfulapi2 0 for generic table - [Pb] replacerecord2 0 Introductionbrief introductionAdd a new record or replace the old one with a new one. If the record already exists, update it; If the record does not exist, insert a new record.POST http://{Tcaplus_REST_URL}Request syntaxHttp request#Tencent cloud console RESTful ...

1, Common commands for keys keys * View all current key exists key Judge a key Does it exist type key View your key What type is it del key Delete the specified key data unlink key according to value Select non blocking delete to delete only keys from keyspace If the metadata is deleted, the real deletion will be carried out in subsequent asyn ...

[tcallusdb knowledge base] restfulapi2 0 for list table - [Pb] listdeleterecord2 0 Introductionbrief introductionDelete the record of the specified subscript under the corresponding Key in the List PB table.Index: Specifies the subscript of the record to delete.POST http://{Tcaplus_REST_URL}Request syntaxHttp request#Tencent cloud console RESTf ...