SELECT column, another_column, …
FROM mytable
WHERE condition
    AND/OR another_condition
    AND/OR …;
= salary = 50000
!= / <> department != 'HR'
>, <, >=, <= salary > 50000
AND salary > 50000 AND department = 'IT'
OR department = 'IT' OR department = 'HR'
IN (…) id IN (1, 2, 3)
NOT IN (…) id NOT IN (1, 2, 3)
BETWEEN … AND … salary BETWEEN 40000 AND 60000
NOT BETWEEN … AND … salary NOT BETWEEN 40000 AND 60000 

-- Фильтрация по одному условию
SELECT * FROM employees WHERE salary > 50000;

-- Комбинация условий с AND
SELECT * FROM employees WHERE department = 'IT' AND salary > 60000;

-- Комбинация условий с OR
SELECT * FROM employees WHERE department = 'IT' OR department = 'HR';

-- Использование IN и NOT IN
SELECT * FROM employees WHERE id IN (1, 2, 3);
SELECT * FROM employees WHERE id NOT IN (1, 2, 3);

-- Диапазоны с BETWEEN
SELECT * FROM employees WHERE salary BETWEEN 40000 AND 60000;
SELECT * FROM employees WHERE salary NOT BETWEEN 40000 AND 60000;

    Далее