Examples of usage of csvsql

Here are a few simple examples of SQL you can use in csvsql: (See example data here)

To get all the data from a file named file.csv:
```
SELECT * FROM file;
```
To get only the name and price columns from a file named products.csv in a directory availability/customers/details/, ordered from cheapest to most expensive:
```
SELECT
  name, price
FROM 
  availability.customers.details.products
WHERE
  price IS NOT NULL
ORDER BY price;
```

To count and get the age range of dogs saved in a file called pets.csv:

SELECT
 MIN(age), MAX(age), COUNT(*)
FROM pets
WHERE type = 'dog';

To count and get the age range of all the pets saved in a file called pets.csv by type of pet, where the number of pets is larger than 20:
```
SELECT
 type, MIN(age), MAX(age), COUNT(*)
FROM pets
GROUP BY type
HAVING COUNT(*) > 20;
```

To get the addresses of the owners of the 10 oldest pets:

SELECT
 owners.name, owners.address
FROM pets, owners
WHERE pets.owner_id = owners.id
ORDER BY pets.age DESC
LIMIT 10;

Working on a temporary table:

First we can create a temporary table that includes only the cats that are older than 3:

CREATE TEMPORARY TABLE older_cats AS
SELECT *
FROM pets
WHERE pets.type = 'cat' AND pets.age > 3;

Now we can find all the owners of those cats:

SELECT
    older_cats.id AS id,
    owners.name AS owner_name,
    older_cats.name AS cat_name,
    phone
FROM older_cats
JOIN owners ON owners.id = older_cats.owner_id
ORDER BY owners.name;

Then we can delete a few rows from the temporary table:

DELETE FROM older_cats WHERE id IN (1656517935, 9848604329, 7999194771);

And when we finish working on the table, we can drop it:

DROP TABLE older_cats;