• Basic statements of MySQL operation


    Basic statements of MySQL operation 1、Create database create database test1; 2、Show all databases show databases; 3、Select a database use test1; 4、Display all tables in a database show tables; 5、Create table create table emp( name varchar(10), hiedate date, sal decimal(10, 2), deptno int(2) ); 6、View table structure 1、desc emp; 2、show create table emp \G; 7、Delete table […]

  • Non blocking mybatis based on MySQL asynchronous driver


    Although spring5 also launched Webflux, a set of asynchronous technology stack, which greatly improves the throughput, has become popular in node, but asynchrony is still not the mainstream in the Java world. Vertx has done a lot of support for asynchrony, but its encapsulation of the data access layer is still very simple, Traditional javaer […]

  • [go] golang exercise item – addition, deletion, query and modification of Gorm and MySQL


    The following code is placed in users.go under the models package The table structure is consistent with the struct field. Change the underline of the table field into a hump named with capital letters Create, find, delete and update users. See the following specific methods   package models import ( _ “github.com/jinzhu/gorm/dialects/mysql” ) type User […]

  • Common syntax for PostgreSQL


    Common syntax for PostgreSQL SQL statement for creating database table: CREATE TABLE “public”.”tb_test” ( “id” int8 NOT NULL, “title” varchar(50) COLLATE “pg_catalog”.”default”, “ip” varchar(50) COLLATE “pg_catalog”.”default”, “param” varchar(500) COLLATE “pg_catalog”.”default”, “result” varchar(500) COLLATE “pg_catalog”.”default”, “type” varchar(10) COLLATE “pg_catalog”.”default” NOT NULL, “create_by” varchar(30) COLLATE “pg_catalog”.”default”, “create_time” timestamptz(6), “update_by” varchar(30) COLLATE “pg_catalog”.”default”, “update_time” timestamptz(6), “remark” varchar(500) COLLATE […]

  • Basic redis operation – hash


    Redis hash is a mapping table of field and value of string type. Hash is especially suitable for storing objects. Each hash in redis can store 232 – 1 key value pair (more than 4 billion).   1、 Set the value of the field field in the hash table key to value Commands: hset Format: hset […]

  • Framework problems encountered in company development


    Framework problems encountered in company development 1.1 database update statement problem (1) Update can be two parameters. The first parameter is to find the corresponding data according to what conditions, and the second parameter can be the table field to be updated

  • [Oracle] – function: recursive function (start with)


    Preface We may encounter this requirement: the field of a table is ID, PID (parent ID); we need to find all its parent nodes by ID. The recursive function operation of start with is provided in Oracle, which can meet the above requirements <br/> <br/> 1. Grammar Select… From [table name] Where [condition 3] Start […]

  • Operation of TP framework on Database


    1. Add data 1.1 add a piece of data $user = new User; $user->name = ‘thinkphp’; $user->email = ‘[email protected]’; $user->save(); $user = new User; $user->save([ ‘name’ => ‘thinkphp’, ’email’ => ‘[email protected]’ ]);            1.2 filtering data from non data table fields $user = new User; //Filtering non data table field data […]

  • MySQL in simple language


    SQL classification DDL DDL (data definition language): data definition language, which defines different database objects. Keywords include:create,drop,alter 1. Create database CREATE DATABASE dbname mysqlDescription of the automatically created database: infomation_schema: object information of database, such as user table, column, permission, character set, partition, etc; cluster: system cluster information; mysql: user permission information of the system; […]

  • What format should I choose for writing


    Markdown and rich text I don’t know if you have paid attention to the editor when you usually write, some of them aremarkdownEditor, there are all kinds of rich text editor, which one to choose believe you have your own judgment If you just write on a platform, it doesn’t matter which editor you like […]

  • Markdown: Foundation, Editor and Graphic Bed


    I. Writing typesetting is a difficult problem Writing is an indispensable part of everyone’s daily life and work, whether it is blogging, e-mail, or writing reports, writing interface documents, writing project plan documents. When writing with Word or similar editing tools, you must have been involved in typesetting problems such as fonts, fonts, spacing, etc. […]

  • Writing Tool Markdown: Writing Specification


    This article will introduce Markdown Typical usage scenarios for Markdown Tags Optimizing typesetting by using space, blank line, indentation and other elements Standards for Common Chinese Punctuation Symbols These are common format guidelines for Markdown’s writing, as well as format conventions. Complying with them can make typesetting more beautiful, more convenient to read, and also […]