commit 83ea94081a2898d48ac96df4d072c31db749cce0 Author: liyuxin <1579178744@qq.com> Date: Fri Jul 19 10:06:29 2024 +0700 test02 diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..5ff6309 --- /dev/null +++ b/.gitignore @@ -0,0 +1,38 @@ +target/ +!.mvn/wrapper/maven-wrapper.jar +!**/src/main/**/target/ +!**/src/test/**/target/ + +### IntelliJ IDEA ### +.idea/modules.xml +.idea/jarRepositories.xml +.idea/compiler.xml +.idea/libraries/ +*.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 \ No newline at end of file diff --git a/.idea/.gitignore b/.idea/.gitignore new file mode 100644 index 0000000..13566b8 --- /dev/null +++ b/.idea/.gitignore @@ -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 diff --git a/.idea/encodings.xml b/.idea/encodings.xml new file mode 100644 index 0000000..aa00ffa --- /dev/null +++ b/.idea/encodings.xml @@ -0,0 +1,7 @@ + + + + + + + \ No newline at end of file diff --git a/.idea/misc.xml b/.idea/misc.xml new file mode 100644 index 0000000..132404b --- /dev/null +++ b/.idea/misc.xml @@ -0,0 +1,14 @@ + + + + + + + + + + \ No newline at end of file diff --git a/.idea/vcs.xml b/.idea/vcs.xml new file mode 100644 index 0000000..35eb1dd --- /dev/null +++ b/.idea/vcs.xml @@ -0,0 +1,6 @@ + + + + + + \ No newline at end of file diff --git a/pom.xml b/pom.xml new file mode 100644 index 0000000..06885f5 --- /dev/null +++ b/pom.xml @@ -0,0 +1,17 @@ + + + 4.0.0 + + com.bwie + test02 + 1.0-SNAPSHOT + + + 8 + 8 + UTF-8 + + + diff --git a/sql/test002.sql b/sql/test002.sql new file mode 100644 index 0000000..e780ca4 --- /dev/null +++ b/sql/test002.sql @@ -0,0 +1,117 @@ +/* + Navicat Premium Data Transfer + + Source Server : lyx + Source Server Type : MySQL + Source Server Version : 50736 + Source Host : 111.229.181.183:3306 + Source Schema : test002 + + Target Server Type : MySQL + Target Server Version : 50736 + File Encoding : 65001 + + Date: 19/07/2024 09:07:53 +*/ + +SET NAMES utf8mb4; +SET FOREIGN_KEY_CHECKS = 0; + +-- ---------------------------- +-- Table structure for stu_cou +-- ---------------------------- +DROP TABLE IF EXISTS `stu_cou`; +CREATE TABLE `stu_cou` ( + `sc_id` int(11) NOT NULL AUTO_INCREMENT, + `c_id` int(11) NULL DEFAULT NULL, + `s_id` int(11) NULL DEFAULT NULL, + PRIMARY KEY (`sc_id`) USING BTREE +) ENGINE = InnoDB AUTO_INCREMENT = 14 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_general_ci ROW_FORMAT = Dynamic; + +-- ---------------------------- +-- Records of stu_cou +-- ---------------------------- +INSERT INTO `stu_cou` VALUES (1, 1, 1); +INSERT INTO `stu_cou` VALUES (2, 1, 2); +INSERT INTO `stu_cou` VALUES (3, 1, 5); +INSERT INTO `stu_cou` VALUES (4, 2, 3); +INSERT INTO `stu_cou` VALUES (5, 2, 4); +INSERT INTO `stu_cou` VALUES (6, 2, 7); +INSERT INTO `stu_cou` VALUES (7, 2, 9); +INSERT INTO `stu_cou` VALUES (8, 3, 10); +INSERT INTO `stu_cou` VALUES (9, 3, 6); +INSERT INTO `stu_cou` VALUES (10, 3, 8); +INSERT INTO `stu_cou` VALUES (11, 2, 8); +INSERT INTO `stu_cou` VALUES (12, 1, 10); +INSERT INTO `stu_cou` VALUES (13, 3, 2); + +-- ---------------------------- +-- Table structure for t_course +-- ---------------------------- +DROP TABLE IF EXISTS `t_course`; +CREATE TABLE `t_course` ( + `c_id` int(11) NOT NULL AUTO_INCREMENT, + `c_name` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL, + PRIMARY KEY (`c_id`) USING BTREE +) ENGINE = InnoDB AUTO_INCREMENT = 7 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_general_ci ROW_FORMAT = Dynamic; + +-- ---------------------------- +-- Records of t_course +-- ---------------------------- +INSERT INTO `t_course` VALUES (1, '英语'); +INSERT INTO `t_course` VALUES (2, '语文'); +INSERT INTO `t_course` VALUES (3, '数学'); + +-- ---------------------------- +-- Table structure for t_student +-- ---------------------------- +DROP TABLE IF EXISTS `t_student`; +CREATE TABLE `t_student` ( + `s_id` int(11) NOT NULL AUTO_INCREMENT, + `s_name` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL, + `sex` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL, + PRIMARY KEY (`s_id`) USING BTREE +) ENGINE = InnoDB AUTO_INCREMENT = 21 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_general_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', '女'); +INSERT INTO `t_student` VALUES (3, '王五', '男'); +INSERT INTO `t_student` VALUES (4, '赵六', '女'); +INSERT INTO `t_student` VALUES (5, '田七', '男'); +INSERT INTO `t_student` VALUES (6, '晓丽', '女'); +INSERT INTO `t_student` VALUES (7, '关谷', '男'); +INSERT INTO `t_student` VALUES (8, '架子', '男'); +INSERT INTO `t_student` VALUES (9, '淞沪', '女'); +INSERT INTO `t_student` VALUES (10, '威威', '女'); + +SET FOREIGN_KEY_CHECKS = 1; + + +-- 查询男生人数 +SELECT COUNT(*) AS count +FROM t_student +WHERE sex = '男'; + +-- 查询女生人数 +SELECT COUNT(*) AS n_count +FROM t_student +WHERE sex = '女'; + +-- 查询男生占比 +SELECT COUNT(*) * 100.0 / (SELECT COUNT(*) FROM t_student) AS people_nan +FROM t_student +WHERE sex = '男'; + +-- 查询女生占比 +SELECT COUNT(*) * 100.0 / (SELECT COUNT(*) FROM t_student) AS people_nv +FROM t_student +WHERE sex = '女'; + +-- 查询每门课程下的学生总人数 +SELECT c.c_name AS course_name, COUNT(sc.s_id) AS student_count +FROM t_course c + LEFT JOIN stu_cou sc ON c.c_id = sc.c_id +GROUP BY c.c_name diff --git a/理论/屏幕截图 2024-07-19 100053.png b/理论/屏幕截图 2024-07-19 100053.png new file mode 100644 index 0000000..30778b2 Binary files /dev/null and b/理论/屏幕截图 2024-07-19 100053.png differ diff --git a/理论/屏幕截图 2024-07-19 100108.png b/理论/屏幕截图 2024-07-19 100108.png new file mode 100644 index 0000000..fd639cb Binary files /dev/null and b/理论/屏幕截图 2024-07-19 100108.png differ diff --git a/理论/屏幕截图 2024-07-19 100116.png b/理论/屏幕截图 2024-07-19 100116.png new file mode 100644 index 0000000..d9ef234 Binary files /dev/null and b/理论/屏幕截图 2024-07-19 100116.png differ