Mybatis integrates Spring's original Dao and Mapper proxy development

Before explaining the original Dao development and Mapper agent development, let's start with the original JDBC and Spring integration JDBC, and look at the entire technical design idea, we will understand the framework principle more easily. Original JDBC: try { // Original Jdbc operation String sql = "insert into cele ...

Posted on Mon, 29 Apr 2019 12:30:36 -0700 by ednark

Migrating Oracle 11g R2 To Oracle 19c

All environments in this article use the same operating system: Oracle Linux 7.5.11g data files are stored on the file system, 19c data files are stored on ASM, NFS is used to temporarily store data files in the middle, and then migrated through rman's transportable tablespace characteristics. 1. Source End Check Since rman cannot automaticall ...

Posted on Mon, 29 Apr 2019 04:30:36 -0700 by dotbands

Dry Goods|Interpret MySQL 8.0 New Features: Skip Scan Range

MySQL has supported a new range scan approach, called Loose Skip Scan, since version 8.0.13.This feature was contributed by Facebook.We know that in previous versions, if an index was to be used for scanning, conditions had to satisfy index prefix columns, such as index idx(col1,col2). If the where condition contained only col2 ...

Posted on Sat, 27 Apr 2019 22:10:35 -0700 by packland

MyBatis Delayed Loading

What is lazy loading Data is loaded only when needed, and no need not be unloaded. Benefits: First query from a single table, then query from an associated table when needed, to improve database performance. Disadvantage: It takes a long time to query data in large quantities. Implementation needs Requirements: Query Acco ...

Posted on Sat, 27 Apr 2019 10:48:34 -0700 by ratebuster

Implementation of DAO on how2j

Implementation of DAO on how2j What's on how2j, I tidy up the upload. The code I typed by hand is running the upload. The implementation of DAO is as simple as a code overview Two points of knowledge: ORM = Object Relationship Database Mapping Mapping of objects and relational databases Simply put, an object corresponds to ...

Posted on Fri, 26 Apr 2019 13:00:36 -0700 by Kenwio

JDBC for oracle learning notes

JDBC use 1. guide pack Import dependency packages directly using IDEA Create a new lib and put the jar package here 2. Load Driver Class.forName("oracle.jdbc.driver.OracleDriver"); 3. Create Connection Objects Connect to the database to get the Connection object String url = "jdbc:oracle:thin:@localhost:1521:ORCL";//Specific instance name can s ...

Posted on Thu, 25 Apr 2019 16:51:35 -0700 by cortez

Summary of SQL Server Database Files and File Groups

File and File Group Concept   For documents and file groups, a brief summary is as follows. For details, please refer to the official documents.“ Database Files and Filegroups ” More relevant information:   Data file concept:   Each SQL Server database contains at least two system files: a data file and a log file. Data files contai ...

Posted on Wed, 24 Apr 2019 20:27:36 -0700 by driverdave

Introduction of SPARQL Query Statement

title: SPARQL statement query date: 2019-04-13 18:23:05 tags: [SPARQL, Jena, Knowledge Map] categories: knowledge map Recently, I learned something about graph, among which SPARQL is the most commonly used query for RDF data. I simply learned its language, which is similar to SQL statements. Matching queries: queries for p ...

Posted on Wed, 24 Apr 2019 16:03:34 -0700 by Thikho

mongodb additions, deletions, censorship and modifications

Installation module pip install pymongo MongoClient object: Used to establish a connection with the MongoDB server client=MongoClient('host ip', port) DataBase objects: corresponding to databases in MongoDB db=client. database name Collection objects: corresponding to collections in MongoDB col=db. Collection name Cursor object: The obje ...

Posted on Tue, 23 Apr 2019 20:57:35 -0700 by redarrow

Demonstration of SQL Injection Principle

Talking about SQL Injection The so-called SQL injection is by inserting SQL commands into the Web form Submit or enter the query string of domain name or page request, and ultimately cheat the server to execute malicious SQL commands. Specifically, it uses existing applications to inject (malicious) SQL commands into the abil ...

Posted on Tue, 23 Apr 2019 11:27:34 -0700 by ionik