Conditional statements part 2

Creating a query with only one condition is not sufficient. Sometimes we would like to check something more complicated. For that SQL (and many other programming languages) have the  AND ,  OR , and  NOT  keywords to increase our ability to fetch the right result we need. 
 The  AND  and  OR  keywords are used like this: 
 SELECT col1, col2

FROM table1
WHERE condition1 AND condition2 OR condition3 ...
 
 
 
 
 
 
 We can stack as many conditions as we want together. 
 
 people 
 
 
 
 
 
 name 
 age 
 gender 
 
 
 
 
 Joas 
 13 
 male 
 
 
 Holwa 
 17 
 male 
 
 
 Nohlas 
 24 
 female 
 
 
 Polar 
 23 
 male 
 
 
 Loopa 
 18 
 female 
 
 
 
 
 
 The  AND  keyword means that  both  conditions must be true; if either of them is not, then the condition will not be met. 
 For example, if we will write 
 SELECT *

FROM people
WHERE gender = "female" AND age < 20
 
 
 
 
 
 
 It means that we are looking for all records that the gender is "female" and the age is less than 20. 
 This will be the result: 
 
 
 
 
 
 name 
 age 
 gender 
 
 
 
 
 Loopa 
 18 
 female 
 
 
 
 
 
 The  OR  keyword means that we want one of the conditions will be true. 
 For example, if we take the same example from above and change the  AND  keyword to  OR 
 SELECT *

FROM people
WHERE gender = "female" OR age < 20
 
 
 
 
 
 
 It means that we are looking for all records that either the gender is female or the age is less than 20. 
 This will be the result: 
 
 
 
 
 
 name 
 age 
 gender 
 
 
 
 
 Joas 
 13 
 male 
 
 
 Holwa 
 17 
 male 
 
 
 Nohlas 
 24 
 female 
 
 
 Loopa 
 18 
 female 
 
 
 
 
 
 The  NOT  keywords mean that we don't want the condition to be met. 
 For example, if we write: 
 SELECT *

FROM people
WHERE NOT gender = "male"
 
 
 
 
 
 
 This will be the result: 
 
 
 
 
 
 name 
 age 
 gender 
 
 
 
 
 Nohlas 
 24 
 female 
 
 
 Loopa 
 18 
 female