SQL

Question 1

How do you add a row to a SQL table?

Answer 1

insert into “tableName” (“columnName1”, “columnName2”, “columnName3”, “columnName4”)
values (‘valueForColumnName1’, ‘valueForColumnName2’, valueForColumnName3, ‘valueForColumnName4’);
returning *;

for values, text values go into single quotes; numbers do not

Question 2

What is a tuple?

Answer 2

In SQL, a list of values is referred to as a tuple.

Source: sql-insert exercise documentation

Question 3

How do you add multiple rows to a SQL table at once?

Answer 3

insert into “tableName” (“columnName1”, “columnName2”, “columnName3”, “columnName4”)
values (‘row1valueForColumnName1’, ‘row1valueForColumnName2’, row1valueForColumnName3, ‘row1valueForColumnName4’),
(‘row2valueForColumnName1’, ‘row2valueForColumnName2’, row2valueForColumnName3, ‘row2valueForColumnName4’),
(‘row3valueForColumnName1’, ‘row3valueForColumnName2’, row3valueForColumnName3, ‘row3valueForColumnName4’)
returning *;

for values, text values go into single quotes; numbers do not

each tuple would be separated by a comma

Question 4

How do you get back the row being inserted into a table without a separate select statement?

Answer 4

returning clause

Question 5

How do you update rows in a database table?

Answer 5

update “tableName”
set “columnName” = value (not in quotes if this is a number)
where “idName” = idNumber(this is a number btw im);

Question 6

Why is it important to include a where clause in your update statements?

Answer 6

Because then it would update every row in the table! VERY BAD thats not what we want

Question 7

How do you delete rows from a database table?

Answer 7

delete from “tableName”

where “columnName” = value;

Question 8

How do you accidentally delete all rows from a table?

Answer 8

delete from “tableName”;

Question 9

What are some examples of aggregate functions?

Answer 9

average(), max(), min(), sum(), count()

Question 10

What is the purpose of a group by clause?

Answer 10

to separate the rows into their own groups and perform aggregate functions