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SQL SELECT MIN

    SQL Min()関数はSQLの集計関数です。 SQL Min()は、指定された条件の最小値を返します。式は数値の場合もあれば、式の場合もあります。

    select min関数の構文:

    SELECT MIN(column_name)
    FROM table_name WHERE conditions;

    SQLSELECTMINについて詳しく見ていきましょう。

    次のレコードがある既存のテーブルを検討してください:

    テーブル:従業員

    EMPLOYEEID

    FIRST_NAME

    LAST_NAME

    給与

    都市

    部門

    MANAGERID

    1001

    VAIBHAVI

    MISHRA

    65500

    PUNE

    ORACLE

    1

    1002

    VAIBHAV

    SHARMA

    60000

    NOIDA

    C#

    5

    1003

    NIKHIL

    VANI

    50500

    JAIPUR

    FMW

    2

    2001

    PRACHI

    SHARMA

    55500

    チャンディーガル

    ORACLE

    1

    2002

    BHAVESH

    JAIN

    65500

    PUNE

    FMW

    2

    2003

    RUCHIKA

    JAIN

    50000

    ムンバイ

    C#

    5

    3001

    PRANOTI

    SHENDE

    55500

    PUNE

    JAVA

    3

    3002

    ANUJA

    WANRE

    50500

    JAIPUR

    FMW

    2

    3003

    DEEPAM

    JAUHARI

    58500

    MUMBAI

    JAVA

    3

    4001

    RAJESH

    GOUD

    60500

    ムンバイ

    テスト

    4

    4002

    ASHWINI

    BAGHAT

    54500

    NOIDA

    JAVA

    3

    4003

    RUCHIKA

    AGARWAL

    60000

    DELHI

    ORACLE

    1

    5001

    ARCHIT

    SHARMA

    55500

    DELHI

    TESTING

    4

    Example 1: Write a query that finds employees' minimum salaryfrom the employees' table.

    SELECT MIN(SALARY) AS 'MINSALARY' FROM
    EMPLOYEES;

    Wefind the minimum salary from the entire employees' table in the above query.The salary will display as the column name when the output is returned. We havealiased the Min (Salary) expression as min salary.

    Output:

    MINSALARY

    50000


    As you can see that the minimum salary is 50000 fromthe employees' table.

    Example 2: Write a query to find the minimum salary ofemployees whose city is Pune from the employees' table.

    SELECT CITY, MIN(SALARY) AS 'SALARY'  FROM EMPLOYEES WHERE CITY = 'PUNE';

    We have aliased min (Salary) in the above query,displayed as column name when output is returned. We have found the minimumsalary of an employee whose city is Pune and displayed the city name.

    Output:

    CITY

    SALARY

    PUNE

    55500


    As you can see, the minimum salary of an employeefrom Pune city is 55500.

    Example 3: Write a query to find the employees' minimum salaryfrom the employees' table of employees whose department is Oracle.

    SELECT DEPARTMENT, MIN(SALARY) AS 'MINIMUM_SALARY'  FROM EMPLOYEES WHERE DEPARTMENT = 'JAVA';

    In the above query, we have aliased min (Salary) asminimum_salary, displayed as column name when output is returned. We have foundthe minimum salary of an employee whose department is Java and displayed thedepartment name.

    Output:

    DEPARTMENT

    MINIMUM_SALARY

    JAVA

    54500


    As you can see, the minimum salary of an employeefrom the Java department is 54500.

    Example 4: Write a query to find the minimum salary ofemployees whose department includes one of the lists is Oracle and FMW from theemployees' table.

    SELECT MIN(SALARY) AS 'SALARY'  FROM EMPLOYEES WHERE DEPARTMENT IN ('ORACLE',
    'FMW');

    We have aliased min (Salary) in the above query,displayed as column name when output is returned. We have found the minimumsalary of an employee whose department is oracle and FMW.

    Output:

    SALARY

    50500


    Example 5: Write a query to find the minimum salary ofemployees whose salary is greater than 50000 and whose city includes Pune,Mumbai from the employees' table group by city.

    SELECT CITY, MIN(SALARY) AS EMPLOYEE_SALARY
    FROM EMPLOYEES WHERE SALARY > 50000 AND CITY IN ('PUNE', 'MUMBAI') GROUP BY
    CITY;

    In the above query, we have aliased Min (Salary) asEMPLOYEE_SALARY, displayed as column name when output is returned. We also usedthe GROUP BY clause followed by the city column. We have found the minimumsalary of an employee whose salary is greater than 50000. Also, the employeecity must be one of the names included in the city IN parameter. The Pune citywill be grouped into one city of all the employees whose city is Pune and foundthe employees' salary, and the same approach is used for Mumbai city.

    Output:

    CITY

    EMPLOYEE_SALARY

    MUMBAI

    58500

    PUNE

    55500


    In Mumbai city, the minimum salary is 58500, andPune city's minimum salary is 55500.

    Example 6: Write a query to find the minimum employee salaryfrom the employee's table unique cities of employees group by city.

    SELECT CITY, MIN(DISTINCT SALARY) AS
    'EMPLOYEE_SALARY' FROM EMPLOYEES GROUP BY CITY;

    In the above query, we have aliased min (DISTINCT salary)as Employee_salary, displayed as column name when output is returned. We havefound the minimum employee salary from the employees' table considering uniquecities in a group by city column.

    Output:

    CITY

    EMPLOYEE_SALARY

    CHANDIGARH

    55500

    DELHI

    55500

    JAIPUR

    50500

    MUMBAI

    50000

    NOIDA

    54500

    PUNE

    55500


    Example 7: Write aquery to find the minimum employee salary from the employee's table uniquedepartment of employees group by the department.

    SELECT DEPARTMENT, MIN(DISTINCT SALARY)
    AS 'EMPLOYEE_SALARY' FROM EMPLOYEES GROUP BY DEPARTMENT;

    In the above query, we have aliased min (DISTINCTsalary) as Employee_salary, displayed as column name when output is returned.We have found the minimum employee salary from the employees' table consideringunique departments grouped by department column.

    Output:

    DEPARTMENT

    EMPLOYEE_SALARY

    C#

    50000

    FMW

    50500

    JAVA

    54500

    ORACLE

    55500

    TESTING

    55500


    Example 8: Writea query to find the minimum salary of the employee from the employee's tablegroup by the city where the aggregate salary is greater than 50000

    SELECT CITY, MIN(SALARY) AS SALARY FROM
    EMPLOYEES GROUP BY CITY HAVING MIN(SALARY) > 50000;

    We have aliased min (Salary) in the above query,displayed as column name when output is returned. We have found minimum emsployeesalary from the employees' table followed group by city name and used having acondition where aggregate is greater than 50000.

    Output:

    CITY

    SALARY

    CHANDIGARH

    55500

    DELHI

    55500

    JAIPUR

    50500

    NOIDA

    54500

    PUNE

    55500


    Here, we can see only cities with aggregate salariesare greater than 50000. Having a clause is like where clause. Having clause isused when we want to apply some condition to the aggregate function. We usedhaving clause only when we used aggregate function in the query.

    Example 9: Write a query to find an employee's minimum salarywith a manager group.

    SELECT DEPARTMENT, MIN(SALARY) AS SALARY
    FROM EMPLOYEES WHERE MANAGERID IN (SELECT MANAGERID FROM MANAGER) GROUP BY
    DEPARTMENT;

    We have aliased min (Salary) in the above query,displayed as column name when output is returned. Explanation of the abovequery, First sub-query will get executed (SELECT MANAGERID FROM MANAGER); as aresult, we will get the employee ids, including the null value. After thesub-query is executed, the main query will get executed SELECT DEPARTMENT, MIN(SALARY)AS SALARY FROM EMPLOYEES WHERE MANAGERID IN (output of sub-query). In the INoperator of the main query, there is an employee's id, which is output from thesub-query according to the IN operator. We will get our final result which isthe group by department name.

    Output:

    DEPARTMENT

    SALARY

    C#

    50000

    FMW

    50500

    JAVA

    54500

    ORACLE

    55500

    TESTING

    55500



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