Programmer Help

Why have multiple watches? – create an employee table, including the following (id, name, age, dep_name, dep_location),id primary key, automatic growth, and add 5 pieces of data Code example: CREATE TABLE emp ( id INT PRIMARY KEY auto_increment, name VARCHAR(40), age int, dep_name VARCHAR(40), dep_location VARCHAR(30) ); INSERT INTO em ...

Python Operates MySQL and Actual Warfare Course Objectives: Master transactions and locks as well as Python development prerequisites for operating MySQL. Course Summary: Transaction: Atomic operations succeed or fail. Locks: If many people are working on the database at the same time, data clutter may occur. MySQL's own locks can solve this ...

9. Mysql advanced 9.1 data addition Learning objectives: understand some advanced operation skills in new data, and improve the efficiency and security of data insertion Batch insertWorm replicationPrimary key conflict Conflict updateConflict replacement 9.1.1 batch insertion concept Batch insert: it is a way to optimize the ...

catalogue Chapter 5: Spring transactions 5.1 transaction management in spring 5.1.1 review of affairs 5.1.2 transaction management in spring 5.2 API of spring transaction management 5.2.1 transaction manager 5.2.2 transaction definition interface 5.2.3 timing of spring committing and rolling back transactions 5.2.4 summarizing Spring t ...

Before reading this article, you need to understand the following questions~ 1, Question 1. What is the partition Partition: it is to store a table data in blocks Objective: to improve the query efficiency of the index 2. Why should MySQL use partitions Start with data analysis Then index optimization is performed Then introduce the par ...

catalogue 1, Connection query 1. Inner connection 2. Left connection 3. Right connection 2, Database function 1. Mathematical function 2. Aggregate function 3. String function 4. Date time function 2. Advantages of stored procedures 3. Create stored procedure 4. Modify and delete stored procedures summary 1, Connection query M ...

1, Database function 1. Mathematical function The records stored in the database often need a series of arithmetic operations, so MySQL supports many mathematical functions. Common mathematical functions Mathematical functiondescribeabs (x)Returns the absolute value of x; The absolute value is always positive, and the absolute value o ...

introduction In enterprise applications, mature businesses usually have a large amount of data. If the reading and writing of MySQL database are operated on one database server, it can not meet the actual needs in terms of security, high availability, high concurrency and so on. Therefore, generally speaking, the Master-Slave replication ...

catalogue preface 1, Preliminary preparation 1. Create a new project and connect to the database 1.1 download MySQL 1.2 on the initial interface of vsial studio 2017, click file - > New - > project, find the Windows form application, modify the project name to xscj, and click save   1.3 four main objects connected to the databa ...

Data CRUD operation CRUD refers to create, retrieve, update and delete. It is also what we often call add, delete, modify and query. insert data 1. Insert a single piece of data INSERT INTO Table name VALUES(val_list); INSERT INTO Table name(col_list) VALUES(val_list); 2. Insert multiple pieces of data INSERT INTO Table name(col_list) ...