日考2
commit
289ac459cf
|
|
@ -0,0 +1,35 @@
|
||||||
|
target/
|
||||||
|
!.mvn/wrapper/maven-wrapper.jar
|
||||||
|
!**/src/main/**/target/
|
||||||
|
!**/src/test/**/target/
|
||||||
|
|
||||||
|
### IntelliJ IDEA ###
|
||||||
|
.idea
|
||||||
|
*.iws
|
||||||
|
*.iml
|
||||||
|
*.ipr
|
||||||
|
|
||||||
|
### Eclipse ###
|
||||||
|
.apt_generated
|
||||||
|
.classpath
|
||||||
|
.factorypath
|
||||||
|
.project
|
||||||
|
.settings
|
||||||
|
.springBeans
|
||||||
|
.sts4-cache
|
||||||
|
|
||||||
|
### NetBeans ###
|
||||||
|
/nbproject/private/
|
||||||
|
/nbbuild/
|
||||||
|
/dist/
|
||||||
|
/nbdist/
|
||||||
|
/.nb-gradle/
|
||||||
|
build/
|
||||||
|
!**/src/main/**/build/
|
||||||
|
!**/src/test/**/build/
|
||||||
|
|
||||||
|
### VS Code ###
|
||||||
|
.vscode/
|
||||||
|
|
||||||
|
### Mac OS ###
|
||||||
|
.DS_Store
|
||||||
|
|
@ -0,0 +1,11 @@
|
||||||
|
<?xml version="1.0" encoding="UTF-8"?>
|
||||||
|
<project version="4">
|
||||||
|
<component name="AnalysisProjectProfileManager">
|
||||||
|
<option name="PROJECT_PROFILE" />
|
||||||
|
<option name="USE_PROJECT_LEVEL_SETTINGS" value="false" />
|
||||||
|
<list size="0" />
|
||||||
|
</component>
|
||||||
|
<component name="SuppressionsComponent">
|
||||||
|
<option name="suppComments" value="[]" />
|
||||||
|
</component>
|
||||||
|
</project>
|
||||||
|
|
@ -0,0 +1,8 @@
|
||||||
|
# Default ignored files
|
||||||
|
/shelf/
|
||||||
|
/workspace.xml
|
||||||
|
# Editor-based HTTP Client requests
|
||||||
|
/httpRequests/
|
||||||
|
# Datasource local storage ignored files
|
||||||
|
/dataSources/
|
||||||
|
/dataSources.local.xml
|
||||||
|
|
@ -0,0 +1,8 @@
|
||||||
|
<?xml version="1.0" encoding="UTF-8"?>
|
||||||
|
<project version="4">
|
||||||
|
<component name="Encoding" defaultCharsetForPropertiesFiles="UTF-8">
|
||||||
|
<file url="file://$PROJECT_DIR$/src/main/java" charset="UTF-8" />
|
||||||
|
<file url="file://$PROJECT_DIR$/src/main/resources" charset="UTF-8" />
|
||||||
|
<file url="PROJECT" charset="UTF-8" />
|
||||||
|
</component>
|
||||||
|
</project>
|
||||||
|
|
@ -0,0 +1,5 @@
|
||||||
|
<component name="InspectionProjectProfileManager">
|
||||||
|
<profile version="1.0">
|
||||||
|
<option name="myName" value="Project Default" />
|
||||||
|
</profile>
|
||||||
|
</component>
|
||||||
|
|
@ -0,0 +1,17 @@
|
||||||
|
<?xml version="1.0" encoding="UTF-8"?>
|
||||||
|
<project version="4">
|
||||||
|
<component name="ExternalStorageConfigurationManager" enabled="true" />
|
||||||
|
<component name="MavenProjectsManager">
|
||||||
|
<option name="originalFiles">
|
||||||
|
<list>
|
||||||
|
<option value="$PROJECT_DIR$/pom.xml" />
|
||||||
|
</list>
|
||||||
|
</option>
|
||||||
|
</component>
|
||||||
|
<component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" default="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
|
||||||
|
<output url="file://$PROJECT_DIR$/out" />
|
||||||
|
</component>
|
||||||
|
<component name="SuppressionsComponent">
|
||||||
|
<option name="suppComments" value="[]" />
|
||||||
|
</component>
|
||||||
|
</project>
|
||||||
|
|
@ -0,0 +1,12 @@
|
||||||
|
<?xml version="1.0" encoding="UTF-8"?>
|
||||||
|
<project version="4">
|
||||||
|
<component name="AnalysisProjectProfileManager">
|
||||||
|
<option name="PROJECT_PROFILE" value="Project Default" />
|
||||||
|
<option name="USE_PROJECT_LEVEL_SETTINGS" value="false" />
|
||||||
|
<scopes />
|
||||||
|
<profiles>
|
||||||
|
<profile profile_name="Project Default" version="1.0" is_locked="false" />
|
||||||
|
</profiles>
|
||||||
|
<list size="0" />
|
||||||
|
</component>
|
||||||
|
</project>
|
||||||
|
|
@ -0,0 +1,17 @@
|
||||||
|
<?xml version="1.0" encoding="UTF-8"?>
|
||||||
|
<project xmlns="http://maven.apache.org/POM/4.0.0"
|
||||||
|
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
|
||||||
|
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
|
||||||
|
<modelVersion>4.0.0</modelVersion>
|
||||||
|
|
||||||
|
<groupId>org.example</groupId>
|
||||||
|
<artifactId>rikao2</artifactId>
|
||||||
|
<version>1.0-SNAPSHOT</version>
|
||||||
|
|
||||||
|
<properties>
|
||||||
|
<maven.compiler.source>8</maven.compiler.source>
|
||||||
|
<maven.compiler.target>8</maven.compiler.target>
|
||||||
|
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
|
||||||
|
</properties>
|
||||||
|
|
||||||
|
</project>
|
||||||
|
|
@ -0,0 +1,74 @@
|
||||||
|
|
||||||
|
|
||||||
|
-- 3.查询男生和女生各多少人。（15分）
|
||||||
|
SELECT sex,count(*) FROM t_student GROUP BY sex
|
||||||
|
|
||||||
|
-- 4. 查询男生和女生分别占总人数的比例。（20分）
|
||||||
|
SELECT sex,ROUND(count(*)/(SELECT count(*) FROM t_student),2) FROM t_student GROUP BY sex
|
||||||
|
|
||||||
|
-- 5.查询每门课程下的学生总人数。（15分）
|
||||||
|
SELECT
|
||||||
|
c.c_name,count(*)
|
||||||
|
FROM
|
||||||
|
t_student s
|
||||||
|
LEFT JOIN stu_cou sc on s.s_id = sc.s_id
|
||||||
|
LEFT JOIN t_course c on c.c_id = sc.c_id GROUP BY c.c_id
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
CREATE TABLE `t_student` (
|
||||||
|
`s_id` int NOT NULL AUTO_INCREMENT,
|
||||||
|
`s_name` varchar(20) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL DEFAULT NULL,
|
||||||
|
`sex` varchar(2) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL DEFAULT NULL,
|
||||||
|
PRIMARY KEY (`s_id`) USING BTREE
|
||||||
|
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;
|
||||||
|
|
||||||
|
-- Records of t_student
|
||||||
|
-- ----------------------------
|
||||||
|
INSERT INTO `t_student` VALUES (1, '张三', '男');
|
||||||
|
INSERT INTO `t_student` VALUES (2, '李四', '男');
|
||||||
|
INSERT INTO `t_student` VALUES (3, '王五', '男');
|
||||||
|
INSERT INTO `t_student` VALUES (4, '赵六', '男');
|
||||||
|
INSERT INTO `t_student` VALUES (5, '田七', '男');
|
||||||
|
INSERT INTO `t_student` VALUES (6, '崔八', '男');
|
||||||
|
INSERT INTO `t_student` VALUES (7, '春兰', '女');
|
||||||
|
INSERT INTO `t_student` VALUES (8, '夏竹', '女');
|
||||||
|
INSERT INTO `t_student` VALUES (9, '秋叶', '女');
|
||||||
|
INSERT INTO `t_student` VALUES (10, '冬梅', '女');
|
||||||
|
|
||||||
|
|
||||||
|
CREATE TABLE `t_course` (
|
||||||
|
`c_id` int NOT NULL AUTO_INCREMENT,
|
||||||
|
`c_name` varchar(20) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL DEFAULT NULL,
|
||||||
|
PRIMARY KEY (`c_id`) USING BTREE
|
||||||
|
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;
|
||||||
|
|
||||||
|
|
||||||
|
INSERT INTO `t_course` VALUES (1, '语文');
|
||||||
|
INSERT INTO `t_course` VALUES (2, '数学');
|
||||||
|
INSERT INTO `t_course` VALUES (3, '英语');
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
CREATE TABLE `stu_cou` (
|
||||||
|
`sc_id` int NOT NULL AUTO_INCREMENT,
|
||||||
|
`c_id` int NULL DEFAULT NULL,
|
||||||
|
`s_id` int NULL DEFAULT NULL,
|
||||||
|
PRIMARY KEY (`sc_id`) USING BTREE
|
||||||
|
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;
|
||||||
|
|
||||||
|
|
||||||
|
INSERT INTO `stu_cou` VALUES (1, 1, 1);
|
||||||
|
INSERT INTO `stu_cou` VALUES (2, 1, 2);
|
||||||
|
INSERT INTO `stu_cou` VALUES (3, 1, 3);
|
||||||
|
INSERT INTO `stu_cou` VALUES (4, 2, 4);
|
||||||
|
INSERT INTO `stu_cou` VALUES (5, 2, 6);
|
||||||
|
INSERT INTO `stu_cou` VALUES (6, 2, 5);
|
||||||
|
INSERT INTO `stu_cou` VALUES (7, 3, 7);
|
||||||
|
INSERT INTO `stu_cou` VALUES (8, 3, 8);
|
||||||
|
INSERT INTO `stu_cou` VALUES (9, 3, 9);
|
||||||
|
INSERT INTO `stu_cou` VALUES (10, 3, 10);
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
@ -0,0 +1,13 @@
|
||||||
|
package org.example;
|
||||||
|
|
||||||
|
/**
|
||||||
|
* @Author：zhangzhihao
|
||||||
|
* @name：${NAME}
|
||||||
|
* @Date：2024/7/19 9:13
|
||||||
|
* 不准抄代码，添加注释，清楚每一行代码意思
|
||||||
|
*/
|
||||||
|
public class Main {
|
||||||
|
public static void main(String[] args) {
|
||||||
|
System.out.println("Hello world!");
|
||||||
|
}
|
||||||
|
}
|
||||||
Loading…
Reference in New Issue