To in Oracle Database_ Usage of the date() function

In an Oracle database, Oracle to_ The date () function is a frequently used function. Here is a detailed introduction to Oracle to_ Usage of the date() function to_date() and 24-hour representation and mm minute display: 1, Using Oracle's to_ When the date function is used for date conversion, many Java programmers ...

Posted by $SuperString on Mon, 01 Jun 2020 17:15:37 +0200

Day 72: use of the PySpider framework

by... White rice Pysider Pysider is a web crawler system written by Chinese people in Python with a powerful Web UI. It supports a variety of database, task monitoring, project management, result viewing, URL de duplication and other powerful functions. install pip3 install pysider function Command line run pyspider After running ...

Posted by deepakagrawal1982 on Mon, 01 Jun 2020 08:22:16 +0200

SpringBoot essay - SpringBoot integrated Druid

1. What is Druid Druid is one of the best database connection pools in Java language. Druid can provide powerful monitoring and extension functions. 2. Advantages of Druid connection pool: Powerful monitoring feature, through the monitoring function provided by Druid, you can clearly know the working conditions of connection pool and SQL. ...

Posted by Nik on Fri, 29 May 2020 16:55:46 +0200

2020.05.28 Database Connection Pool C3P0 Druid JDBCTemplate

Today's Content 1. Database Connection Pool 2. Spring JDBC : JDBC Template Database Connection Pool 1. Concept: It is actually a container (collection) that holds database connections. When the system is initialized, the container is created and some connection objects are requested in the container. When the user accesses the database, ...

Posted by truck7758 on Thu, 28 May 2020 18:22:01 +0200

How ORACLE databases export table structures using the datapump tool and import them under other Schema s

This is a brief introduction to how to export and import table structure definitions using the datapump tool of the ORACLE database.Because business scenarios can be very simple, you won't encounter any problems, or business scenarios can be very complex, and you will encounter a lot of problems.Here's a brief description of what you need.A bat ...

Posted by Hexxx on Thu, 28 May 2020 03:39:28 +0200

[12c] Histograms

Histogram, a special type of statistical information of columns, can provide more detailed data distribution information of columns in the table. Histogram stores values in buckets. Based on the number of different values and the distribution of data, the database selects the type of histogram to be created. The types of histogram are as follow ...

Posted by slibob on Wed, 27 May 2020 14:30:00 +0200

C ා data operation series - 17 Dapper ADO.NET ORM of the same race

0. Preface The previous four articles introduced an excellent framework SqlSugar developed by domestic developers, which gave us a bright feeling in front of our eyes. In this article, we will try another ORM framework, Dapper, which has a relatively high audience rating. Dapper is a lightweight ORM framework, which is characterized by high spe ...

Posted by hip_hop_x on Wed, 27 May 2020 05:53:48 +0200

Self adhesive, thermal printing

In the process of warehousing and logistics, it is often necessary to use thermal printer or carbon tape printer to print some barcode and information and paste them on the physical object or package The best way is not to directly use thermal code to form text and output it to printer for printing But thermal code is also a special language to ...

Posted by gavinbsocom on Wed, 20 May 2020 09:43:00 +0200

Let's use the mybatis framework to add, delete, modify and query mysql database in java

This article will use a simple login comment function to fully introduce the use of mybatis framework. Functions: add, delete, modify, query, multi table query, fuzzy query, dynamic query This article uses the environment / tools: Database: mysql 5.7 JDK:8 IDEA:2020.1 Database visualization tool: Navica ...

Posted by ponsho on Mon, 18 May 2020 08:11:13 +0200

MySql practice many to many table exercise - user role permission table

This paper reviews the knowledge of database, including creating database, creating table, primary key constraint, foreign key constraint and table relation (many to many). 1, Table description A user table, a role table, and a permission table. A user corresponds to multiple roles, a role corresponds to multiple ...

Posted by russthebarber on Sat, 16 May 2020 19:08:22 +0200