Questions 51-61 and Personal Solutions

Catalog 51. Find the number of occurrences of commas in strings'10,A,B','cnt. 52. Get the first_name in Employees, and the query is arranged in ascending order according to the last two letters of the first_name. 53. According to dept_no, emp_no belongs to the same department is connected by comma, and the res ...

Added by villas on Mon, 22 Jul 2019 18:43:34 +0300

04_MyBatis Single Table CRUD and Multiple Table Processing Association Operations

MyBatis single form CRUD operation The CRUD operation of single standard is mainly based on how to write high-quality SQL statements. If the column and entity attributes in the table do not correspond to each other in single standard operation, it is suggested to use aliases for mapping. # The diffe ...

Added by AlGale on Mon, 22 Jul 2019 09:37:06 +0300

oracle function custom procedure parameter execution procedure trigger creates package view to execute sql statement dynamically

function Functions can return, processes can not, processes can be out, functions can also be out, but basically no create function Function name (Parameters) return Return data type is begin end; //Create a function twice, override it for the first time, and do not report an existing error. Add or rep ...

Added by geethalakshmi on Sat, 20 Jul 2019 16:45:16 +0300

SpringBook 9: Integrating Spring Data JPA

Author: Dream Chasing 1819 Original: https://www.cnblogs.com/yanfei1819/p/10910059.html Copyright Statement: This article is the original article of the blogger. Please attach a link to the blog article for reprinting. Preface In the previous chapters, we introduced ORM frameworks such as JDBCTemplate and MyBatis. Let's introduce Spring Data J ...

Added by TimUSA on Fri, 19 Jul 2019 05:42:53 +0300

MySQL DAY2 Basic Tutorial

Table Content MariaDB [company]> SELECT * FROM employee_info; +-----+-------+------+--------+---------+--------+ | id | name | age | salary | address | sex | +-----+-------+------+--------+---------+--------+ | 001 | Alex | 30 | 13000 | NULL | male | | 002 | Jack | 27 | 8500 | NULL | male | | 003 | Cathy | 23 | ...

Added by manmanman on Thu, 18 Jul 2019 03:54:51 +0300

Classification of SQL Query Statements

There are many kinds of SQL query statements, which are summarized below. Firstly, three tables are constructed for later experiments. -- Student table, record student information CREATE TABLE student( sno VARCHAR(10), sname VARCHAR(10), ssex ENUM('male','female'), sage INT, sdept VARCHAR(10), PRIMARY KEY(sno) ); + ...

Added by kmussel on Thu, 18 Jul 2019 01:42:14 +0300

JDBC Connection Database Tutorial, postgreSQL

0. Overview This article uses postgreSQL to connect through JDBC data base Examples of common database operations and JDBC API, JDBC's general workflow and JDBC transactions are introduced. 1. Preparations A. Download and install the postgreSQL database. B. Build a new one Java Project and import the JDBC driver jar package of postgreSQL. ...

Added by zone16 on Wed, 17 Jul 2019 22:46:49 +0300

Thinking in SQL Series 6: Data Mining Apriori Association Analysis to Reproduce the Myth of Beer Diapers

When it comes to data mining machine learning, the myth about beer diapers has long been heard in my impression. This problem often appears in articles related to data warehouses, which shows how far and deep the beer diaper problem has impacted the field of data mining.Look first at the cause: The story of beer and diapers originated in Wal-Ma ...

Added by pothole_89 on Wed, 17 Jul 2019 20:37:02 +0300

Front-end learning path HTML 5 (04) - features

HTML 5 web storage HTML 5's web storage is different from cookie storage, and its storage efficiency is better. Its data can only be accessed by the web page, and the client stores two types of data. Local Storage: Storage without time limit; Session Storage: Storage for a session. <!DOCTYPE html> <html> <head> <meta ...

Added by jefrat72 on Wed, 17 Jul 2019 02:04:00 +0300

PreparedStatement interface in Java

The PreparedStatement interface inherits from the Statement interface and is used to execute pre-compiled SQL statements with or without parameters. Compared with the Statement interface used to execute static SQL statements, the SQL statements in the PreparedStatement interface are precompiled, and the efficiency of repeated execution is highe ...

Added by nosmasu on Tue, 16 Jul 2019 20:44:20 +0300