How to use SQL statements for data analysis and report generation in MySQL?

How to use SQL statements for data analysis and report generation in MySQL?

Data analysis and report generation are processes of in-depth mining and visual display of data. SQL language, as a language used to manage and manipulate relational databases, is widely used in data analysis and report generation. Using SQL statements in MySQL for data analysis and report generation can help us extract the required data from the database, analyze and make statistics on the data through various calculations and conversion operations, and finally generate the required reports.

1. Preparation of database

Before performing data analysis and report generation, we first need to create a database using MySQL and import the data. You can create a database named "test" using the following statement:

CREATE DATABASE test;

Then select the database using the following statement:

USE test;

Next, create a table named "students" and insert some test data:

CREATE TABLE students (

id INT PRIMARY KEY,
name VARCHAR(50),
age INT,
gender VARCHAR(10),
grade INT

);

INSERT INTO students (id, name, age, gender, grade) VALUES
(1, '张三', 18, 'Male', 80),
(2, '李思', 19, 'Female', 90 ),
(3, '王五', 20, 'Male', 85),
(4, 'Zhao Liu', 18, 'Female', 95),
(5, 'Qian Seven', 19, 'Male', 88);

2. Data Analysis

In MySQL, you can use the SELECT statement to query the required data from the table, and perform various calculations and conversion operations. For example, if we want to calculate the average grade and total number of students, we can use the following statement:

SELECT AVG(grade) AS average_grade, COUNT(*) AS total_students FROM students;

This The statement will return a query result containing the average score and total number of students. The results are as follows:

##87.65

average_grade	total_students

Report generation

Report generation is an important part of data analysis. By visualizing the data, it can be more clearly understood Understand relationships and trends in data. In MySQL, you can use the GROUP BY clause of the SELECT statement to group data, and use aggregate functions to obtain statistical values ​​of grouped data. For example, if we want to generate a statistical report on the number of students grouped by gender, we can use the following statement:

SELECT gender, COUNT(*) AS total_students FROM students GROUP BY gender;

This statement A query result containing gender and the corresponding number of students will be returned. The results are as follows:

gendertotal_students##Male##女2##You can use a similar method to generate other statistical reports, for example, press Statistics report on the number of students in age groups: SELECT CASE

3

WHEN age >= 18 AND age <= 20 THEN '18-20'
WHEN age >= 21 AND age <= 25 THEN '21-25'
ELSE '其他'

END AS age_group,

COUNT(*) AS total_students

FROM students

GROUP BY age_group;

This statement will return a query result containing the age group and the corresponding number of students. The results are as follows:

age_grouptotal_students##18-204Others1##Through the flexible use of SQL statements, you can according to actual needs Conduct various analyzes and report generation on data to help us better understand and utilize the data. In practical applications, we can further optimize the performance of query statements and use JOIN operations to associate data from multiple tables. In short, the application of SQL statements in MySQL provides powerful functions and flexibility for data analysis and report generation.

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