连接查询:打印出,每个员工的员工 id、员工姓名、员工工资和员工部门 ( tb_department(部门表)、tb_employee(员工表))
时间: 2023-07-10 07:06:57 浏览: 161
假设 tb_department 表中有字段 department_id, department_name,tb_employee 表中有字段 employee_id, employee_name, employee_salary 和 department_id,可以使用以下 SQL 语句进行连接查询:
```
SELECT tb_employee.employee_id, tb_employee.employee_name, tb_employee.employee_salary, tb_department.department_name
FROM tb_employee
JOIN tb_department ON tb_employee.department_id = tb_department.department_id;
```
执行以上 SQL 语句后,将会打印出每个员工的员工 id、员工姓名、员工工资和员工部门。
相关问题
视图:按照部门分组,统计 tb_employee 中每个部门的平均工资,结果保存为视图, 视图名称为:answer01;tb_department(部门表)、tb_employee(员工表)
可以使用以下 SQL 语句创建视图:
```
CREATE VIEW answer01 AS
SELECT d.department_name, AVG(e.salary) AS avg_salary
FROM tb_employee e
INNER JOIN tb_department d ON e.department_id = d.department_id
GROUP BY d.department_name;
```
该视图按照部门分组,统计每个部门的平均工资,并将结果保存为 `answer01` 视图,其中使用了 `INNER JOIN` 连接 `tb_employee` 和 `tb_department` 表,以便获取员工所在的部门名称。
SELECT t3.id, t3.no, t3.name, t3.orgnization, sex, icno, address, birth, register_date, phone, img_status, finger_print_num, card_num, t3.status,t4.img_template FROM ( SELECT t1.*,t2.name AS 'orgnization' FROM tb_employee t1 INNER JOIN tb_department t2 ON t1.orgnization_id = t2.id )t3 INNER JOIN tb_face t4 ON t3.no = t4.no mybatis如何写
你可以尝试以下的 MyBatis SQL 语句:
```xml
<select id="selectEmployeesWithFace" resultMap="EmployeeResultMap">
SELECT t3.id, t3.no, t3.name, t3.orgnization, sex, icno, address, birth, register_date, phone, img_status, finger_print_num, card_num, t3.status, t4.img_template
FROM (
SELECT t1.*,t2.name AS 'orgnization'
FROM tb_employee t1
INNER JOIN tb_department t2 ON t1.orgnization_id = t2.id
) t3
INNER JOIN tb_face t4 ON t3.no = t4.no
</select>
<resultMap id="EmployeeResultMap" type="Employee">
<id property="id" column="id"/>
<result property="no" column="no"/>
<result property="name" column="name"/>
<result property="orgnization" column="orgnization"/>
<result property="sex" column="sex"/>
<result property="icno" column="icno"/>
<result property="address" column="address"/>
<result property="birth" column="birth"/>
<result property="registerDate" column="register_date"/>
<result property="phone" column="phone"/>
<result property="imgStatus" column="img_status"/>
<result property="fingerPrintNum" column="finger_print_num"/>
<result property="cardNum" column="card_num"/>
<result property="status" column="status"/>
<result property="imgTemplate" column="img_template"/>
</resultMap>
```
在这个例子中,我们定义了一个名为 `selectEmployeesWithFace` 的 SQL 查询语句,它将返回员工列表以及每个员工的人脸图像模板。我们使用了嵌套查询和内部连接,以获取所需的数据。我们还定义了一个名为 `EmployeeResultMap` 的结果映射,它将查询结果映射到 Employee 对象的属性中。
你需要根据你的实际情况来修改这个例子,例如更改表名和列名,以及更改对象的属性名称。
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