Detailed JDBC usage

Introduction to JDBC Java Database Connectivity, (Java Database Connectivity, referred to as JDBC) is an application programming interface used in the Java language to regulate how client programs access the database, and provides methods such as querying and updating data in the database. JDBC is also a trademark of Sun Microsystems. We usua ...

Posted by naomi385 on Sun, 27 Nov 2022 20:52:51 +0300

Pitfalls encountered in Mysql

Pitfalls encountered in Mysql 1. Erdog, when you create a table, do you always set Null as the default value? Damn, how do you know, how simple Null is, how convenient it is to set Null without passing a value, and it doesnโ€™t take up much space, and you donโ€™t need to fill in the code, and you donโ€™t need to judge. Ergou, ...

Posted by onion2k on Sun, 20 Nov 2022 01:41:10 +0300

Computer completed topic selection recommendation spring boot+vue used car trading platform ssm+vue used car auction system used car mall java used car auction system used car trading management system used car trading system

๐Ÿ’–๐Ÿ’– Author: IT Transition Valley Design Exhibition ๐Ÿ’™๐Ÿ’™ Profile: I have been engaged in computer professional training and teaching for a long time, and I also love teaching in class. I am good at Java, WeChat applet, Python, Golang, Android, etc. I usually do some customized project development, code explanation, defense teaching, document wr ...

Posted by Bikkebakke on Sun, 25 Sep 2022 21:45:45 +0300

Supplementary record of sql basic syntax (to be continued 8 / 25)

I haven't done this for a long time. By the way, I was asked about it during the interview 1, distinct 1) Function Remove duplicate items 2) Grammar select distinct Column name from Table name; give an example Before use:(Here you can see that 3 repeat) select client ID from Orders; After use:(It can be seen here that onl ...

Posted by dlebowski on Thu, 25 Aug 2022 12:39:11 +0300

MySQL advanced - six index optimization

Database optimization scheme Index failure, insufficient use of index: index establishmentToo many JOIN (design defects or unavoidable requirements) associated queries: SQL optimizationToo much data: sub database and sub tableServer tuning / optimization and various parameter settings (buffer, number of threads, etc.): adjust my.cnf Performan ...

Posted by tanita on Sat, 06 Aug 2022 21:43:39 +0300

Home stay management system based on javaweb+mysql (java+SSM+JSP+bootstrap+jQuery+mysql)

Front and back end of ssm home stay management system web page Project introduction Tourist functions: user registration, login, login permission interception, search rooms by name, payment process, view order information and status, comment on reserved rooms, automatically modify order status, view and count the number of remaining rooms. When ...

Posted by TronB24 on Wed, 25 May 2022 23:43:22 +0300

JDBC operation data and DAO design pattern in actual combat

Using JDBC to manipulate data 1. Using JDBC to write large text data to the database Purpose: to java and other text files are written to the corresponding fields of the corresponding table by connecting the database with JDBC. 1. Table structure 2. Documents 3. Implementation code for inserting text package LoadFileTest; import driver.JDB ...

Posted by schoi on Wed, 25 May 2022 18:54:45 +0300

MySql advanced master-slave synchronization โ˜†

Master slave synchronization of MySql advanced 1. Replication overview This means that the master and slave databases can be synchronized again by transferring these data to the master and slave databases through the DDL. MySQL supports the replication of one master database to multiple slave databases at the same time. The slave database ca ...

Posted by upit on Wed, 25 May 2022 17:55:35 +0300

MySQL 8.0 window function ranking and topN problems

MySQL 8.0 window function ranking and topN problems I've been using mysql5 7. Unexpectedly, a very useful function - window function is added to 8.0. Here, the window function, its usage and problems that can be solved are summarized as follows ย  what Window function --- also known as OLAP function --- online analytical processing The window fu ...

Posted by fazlionline on Mon, 23 May 2022 10:10:26 +0300

Filters, listeners and mysql

review EL Syntax ${expression} EL domain objects, and lookup rules pageScope requestScope sessionScope applicationScope What is the function of pageContext object in EL You can get other objects ${ pageContext.request.contextPath } How does EL display the attributes of students, elements in list and elements in map ${Student object. Pro ...

Posted by konqest on Mon, 23 May 2022 01:54:54 +0300