------------miscellaneous_income_expenditure----------------
SELECT
	`miscellaneous_income_expenditure`.`id`,
	`miscellaneous_income_expenditure`.`name`,
	`miscellaneous_income_expenditure`.`is_exp_income`,
	CONCAT( users.first_name, " ", users.last_name ) AS "misc_created_by",
	`miscellaneous_income_expenditure`.`created_by` 
FROM
	`miscellaneous_income_expenditure`
	INNER JOIN `users` ON `users`.`id` = `miscellaneous_income_expenditure`.`created_by`(int value) 
WHERE
	`miscellaneous_income_expenditure`.`is_active` = 'Y' ( it is flag we can set value here enum value 0/1or Y/N)
ORDER BY
	`miscellaneous_income_expenditure`.`id` DESC

---------------
SELECT
	STAFF.NAME,
	EMPLOYEE_DETAILS.EMP_SAL,
	STAFF.DEPT_ID 
FROM
	STAFF
	LEFT JOIN EMPLOYEE_DETAILS ON STAFF.DEPT_ID = EMPLOYEE_DETAILS.DESIG_ID 
ORDER BY
	DEPT_ID ASC;

-----------------------second highest salary
SELECT MAX( EMP_SAL ) FROM EMPLOYEE_DETAILS WHERE EMP_SAL <( SELECT MAX( EMP_SAL ) FROM EMPLOYEE_DETAILS );





SET sql_mode = "";
SELECT
	blood_donation_details.donor_id,
	blood_donation_details.donation_datetime,
	patients.id 
FROM
	patients
	LEFT JOIN blood_donation_details ON blood_donation_details.donor_id = patients.id 
WHERE
	donor_id > 1