247 lines
6.0 KiB
Markdown
247 lines
6.0 KiB
Markdown
### C语言-1
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```c
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/*------------------------------------------------------------------------------
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（1）【程序设计】定义一个大小为50的整型数组，将数字1~50存入该数组，利用指针将数组中的值输出，每行5个，每个数字占4个符号位，左对齐。
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------------------------------------------------------------------------------*/
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#include <stdio.h>
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#include <stdlib.h>
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int main()
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{
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int i,*p,array[50];
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for(i=0;i<50;i++)
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{
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array[i]=i+1;
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}
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p=array;
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/**********Program**********/
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//p 一级指针 可以指向整型的一维数组
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for(i=0;i<50;i++){//0~49
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printf("%-4d ", p[i]);
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if((i+1)%5==0){
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printf("\n");
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}
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}
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/********** End **********/
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}
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```
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### C语言-2
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```c
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/*----------------------------------------------------------------------
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【程序设计】
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------------------------------------------------------------------------
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题目：要求实现一个函数，能够合并两个整数数组,合并后进行降序排序并删除重复元素。
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示例1：
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输入输出如下所示：
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请输入第一个数组的6个元素，每个元素之间用空格隔开：1 3 5 7 10 6
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请输入第二个数组的6个元素，每个元素之间用空格隔开：10 4 2 6 11 30
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合并后降序排列的数组：30 11 10 7 6 5 4 3 2 1
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------------------------------------------------------------------------
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注意：请勿改动程序中的其他内容。
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----------------------------------------------------------------------*/
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#include <stdio.h>
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int* mergeArrays(int *arr1, int size1, int *arr2, int size2,int *newLen);
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int main() {
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int size1=6;
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int size2=6;
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int arr1[6];
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int arr2[6];
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int i;
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int newLen = 0;
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int* mergedArray;
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printf("请输入第一个数组的6个元素，每个元素之间用空格隔开：");
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for ( i = 0; i < size1; i++) {
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scanf("%d", &arr1[i]);
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}
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printf("请输入第二个数组的6个元素，每个元素之间用空格隔开：");
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for ( i = 0; i < size2; i++) {
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scanf("%d", &arr2[i]);
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}
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mergedArray = mergeArrays(arr1, size1, arr2, size2, &newLen);
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printf("合并后降序排列的数组：");
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for (i = 0; i < newLen; i++) {
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printf("%d ", mergedArray[i]);
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}
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printf("\n");
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return 0;
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}
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int* mergeArrays(int *arr1,int size1,int *arr2,int size2,int *newLen) {
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static int mergedArray[20];
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/**********Program**********/
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int i, j=0, temp;
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//合并数组
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for(i=0;i<size1;i++){
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mergedArray[j++] = arr1[i];
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mergedArray[j++] = arr2[i];
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}
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//降序排序
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for(i=0;i<size1*2-1;i++){//已经有序的个数
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for(j=0;j<size1*2-i-1;j++){//i每+1 代表最前面已经有一个最小的元素
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if(mergedArray[j] < mergedArray[j+1]){ //无序的元素两两比较小值后移
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temp = mergedArray[j];
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mergedArray[j] = mergedArray[j+1];
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mergedArray[j+1] = temp;
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}
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}
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}
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//去重
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/*
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默认第一个数字不用判断，从数组中第二个元素开始判断，
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是否等于前一项如果不等于则进行赋值操作，然后元素个数加一
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*/
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*newLen = 1;//当前数组中已经过滤后的有效数字个数
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for(i=1;i<size1*2;i++){//使用i变量从1下标元素开始 遍历数组中的所有数字
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if(mergedArray[(*newLen) - 1] != mergedArray[i]){
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//如果当前判断的元素不等于前一个元素则插入到有效数字位置
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mergedArray[(*newLen)++] = mergedArray[i];
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}
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}
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/********** End **********/
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return mergedArray;
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}
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```
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### MySQL-1
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```sql
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#1. 设置字段主键+自动增长
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ALTER TABLE t_user MODIFY uid INT(11) PRIMARY KEY AUTO_INCREMENT;
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#只设置主键
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ALTER TABLE t_user ADD PRIMARY KEY(uid);
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#2. 插入记录
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#DEFAULT 自增/默认值/NULL
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INSERT INTO t_user()
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VALUES(DEFAULT, 'mike', 'mm123', '小明', DEFAULT);
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#3. 更新记录
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UPDATE t_user u
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SET u.`password` = '888888'
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WHERE u.username = 'Dennis';
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#4. tj11 条件查询+多表联查
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SELECT u.nickname, c.mid, c.score, c.content
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FROM t_user u, t_comment c
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WHERE u.uid = c.uid AND u.nickname = '白色';
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#5. tj12 分组查询+多表联查
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SELECT m.mname, ROUND(AVG(c.score), 2)
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FROM t_movie m, t_comment c
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WHERE m.mid = c.mid
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GROUP BY m.mid;
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#6. tj13 分组查询+多表联查
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SELECT m.mname, COUNT(*)
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FROM t_movie m, t_comment c
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WHERE m.mid = c.mid
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GROUP BY m.mid;
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#7 视图 多表联查
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CREATE VIEW v_movie AS
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SELECT m.mname, u.nickname, c.score, c.content
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FROM t_user u, t_movie m , t_comment c
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WHERE u.uid = c.uid AND m.mid = c.mid;
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#8 存储过程
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DELIMITER $$
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DROP PROCEDURE IF EXISTS pro_getUserNumber;
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CREATE PROCEDURE pro_getUserNumber(IN in_uid INT, OUT out_number INT)
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BEGIN
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SET out_number = (
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SELECT COUNT(*)
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FROM t_user u, t_comment c
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WHERE u.uid = c.uid AND u.uid = in_uid
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);
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END $$
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DELIMITER ;
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#9 触发器
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DELIMITER $$
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DROP TRIGGER IF EXISTS tri_userlog;
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CREATE TRIGGER tri_userlog
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AFTER INSERT ON t_user
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FOR EACH ROW
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BEGIN
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INSERT INTO t_log()
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VALUES(DEFAULT, NEW.uid, '新增用户', '2024-01-01');
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END $$
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DELIMITER ;
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```
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### MySQL-2
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```sql
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#1 修改表结构
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ALTER TABLE t_examinee MODIFY sex CHAR(2);
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DESC t_examinee;#查看表结构
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#2 插入记录
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INSERT INTO t_room()
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VALUES(DEFAULT, '202教室', '2号教学楼');
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#3 删除记录
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DELETE FROM t_teacher
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WHERE rid IS NULL;
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#4 更新记录
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UPDATE t_examinee
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SET tel = '1396668888'
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WHERE ename = '龚致远';
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#5 tj11 条件查询+多表联查
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SELECT e.ename, r.rname, r.site
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FROM t_examinee e, t_room r
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WHERE e.rid = r.rid AND e.ename = '陶宇宁';
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#6 tj12
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SELECT r.rname, r.site, t.tname, t.tel
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FROM t_teacher t, t_room r
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WHERE t.rid = r.rid AND r.rname = '402教室';
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#7
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CREATE VIEW v_exam AS
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SELECT e.ename, e.sex, e.tel, e.examnum, r.rname, r.site
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FROM t_examinee e, t_room r
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WHERE e.rid = r.rid;
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#8 存储过程
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DELIMITER $$
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DROP PROCEDURE IF EXISTS pro_getExamNumber;
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CREATE PROCEDURE pro_getExamNumber(IN in_rid INT, OUT out_number INT)
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BEGIN
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SELECT COUNT(*) INTO out_number
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FROM t_examinee e
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WHERE e.rid = in_rid;
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END $$
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DELIMITER ;
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#9 触发器
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DELIMITER $$
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DROP TRIGGER IF EXISTS tri_examlog;
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CREATE TRIGGER tri_examlog
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BEFORE INSERT ON t_examinee
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FOR EACH ROW
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BEGIN
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INSERT INTO t_log()
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VALUES(DEFAULT, NEW.eid, '新增考生', '2024-01-01');
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END $$
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DELIMITER ;
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```
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