Tag Archives: sql commands

OPERATOR PRECEDENCE   Let’s list the employees which JOB_ID is SA_REP or AD_PRES , and have salary more than 15000. SELECT first_name,last_name, job_id, salary FROM hr.employees WHERE job_id = 'SA_REP‘ …

IS NULL OPERATOR Let’s list the employees that have manager. SELECT first_name,last_name, manager_id FROM hr.employees WHERE manager_id IS not NULL;   LOGICAL OPERATORS AND : It returns TRUE if all …

CHAPTER 2 WHERE Conditions Comparison operators BETWEEN operator IN operator LIKE operator IS NULL operator Logical operators AND operator OR operator NOT operator ORDER BY operator   RESTRICTING ROWS WITH …

ARITHMETIC OPERATORS Arithmetic operations can be used on the data which type is ‘date’ or ‘number’. The priority of the operators is like below ;   USAGE OF THE ARITMETHIC …

SELECT Statement Selection : SQL statements are being used to returning the selected lines from related tables. Projection : SQL’s projection ability is being used to returning the selected columns …

CHAPTER 1 – INTRODUCTION TO SQL Explaining the capabilities of the SELECT statement Writing simple SELECT statements Select columns and aliases Arithmetic operators NULL value Union operator Usage of DISTINCT …