.将表departments中的department_id,department_name数据插入新表dept2中
时间: 2023-05-31 10:01:49 浏览: 56
可以使用如下SQL语句:
```
INSERT INTO dept2 (department_id, department_name)
SELECT department_id, department_name
FROM departments;
```
该语句将从departments表中选择department_id和department_name列,并将它们插入到dept2表中。注意,dept2表需要先存在,并且与departments表具有相同的列名和数据类型。
相关问题
strcpy(cf_dept.name, "护理学院"); cf_dept.alumni_list = (struct alumni*)malloc(sizeof(struct alumni) * 60); cf_dept.alumni_count = 0; cf_dept.sub_departments = (struct department*)malloc(sizeof(struct department) * 60); cf_dept.sub_dept_count = 0;这段代码显示[Error] 'cf_dept' was not declared in this scope 的错误,请改正
这段代码中使用了一个名为 "cf_dept" 的变量,但是没有先进行声明。为了解决这个问题,我们需要在代码的前面先声明 "cf_dept" 变量的类型和名称,例如:
```c++
struct department cf_dept;
```
这样就可以在后续的代码中使用 "cf_dept" 变量了。完整的代码如下所示:
```c++
#include <stdlib.h>
#include <string.h>
struct alumni {
char name[20];
int age;
};
struct department {
char name[20];
struct alumni* alumni_list;
int alumni_count;
struct department* sub_departments;
int sub_dept_count;
};
int main() {
struct department cf_dept;
strcpy(cf_dept.name, "护理学院");
cf_dept.alumni_list = (struct alumni*)malloc(sizeof(struct alumni) * 60);
cf_dept.alumni_count = 0;
cf_dept.sub_departments = (struct department*)malloc(sizeof(struct department) * 60);
cf_dept.sub_dept_count = 0;
return 0;
}
```
Write a query to display the department ID, department name ,manager id and first name of manager.
Assuming you are using a database with tables named "departments" and "employees", where the "departments" table has columns "dept_id", "dept_name", and "manager_id", and the "employees" table has columns "emp_id" and "emp_first_name", you can use the following SQL query to display the desired information:
```
SELECT d.dept_id, d.dept_name, d.manager_id, e.emp_first_name
FROM departments d
JOIN employees e ON d.manager_id = e.emp_id;
```
This query joins the "departments" table with the "employees" table on the "manager_id" and "emp_id" columns, and selects the relevant columns to display. The result will be a table with the department ID, department name, manager ID, and first name of the manager for each department.