AND has a higher precedence than OR;

RDBS

will return an error.

OR

has a higher precedence than AND;

We must use parentheses for each condition

No

Yes

SELECT Dept_ID, Job_ID, AVG(Salary) FROM

Employees GROUP BY Dept_ID

SELECT Dept_ID, AVG(Salary) FROM Employees GROUP BY Dept_ID

SELECT AVG(Salary) FROM Employeees GROUP BY Dept_ID

SELECT Dept_ID, Job_ID, AVG(Salary) FROM Employees GROUP BY Dept_ID, Job_ID

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