Encontre a tabela certa

Aplicando SQL a Problemas do Mundo Real

Dmitriy (Dima) Gorenshteyn

Lead Data Scientist, Memorial Sloan Kettering Cancer Center

Homem sobrecarregado olhando para um quadro cheio

Qual tabela usar?

Quais colunas suas tabelas têm?
O que há nessas colunas?

SELECT * 
FROM payment;

Use LIMIT nos resultados

SELECT * 
FROM payment;

rental_id rental_date       inventory_id customer_id return_date
2         2005-05-24 22:54:33    1525    459         2005-05-28 19:40:33
3         2005-05-24 23:03:39    1711    408         2005-06-01 22:12:39
4         2005-05-24 23:04:41    2452    333         2005-06-03 01:43:41
5         2005-05-24 23:05:21    2079    222         2005-06-02 04:33:21
6         2005-05-24 23:08:07    2792    549         2005-05-27 01:32:07
7         2005-05-24 23:11:53    3995    269         2005-05-29 20:34:53
8         2005-05-24 23:31:46    2346    239         2005-05-27 23:33:46
...................16035 MORE ROWS......................................

Use LIMIT nos resultados

SELECT * 
FROM payment
LIMIT 5;

rental_id rental_date       inventory_id customer_id return_date
2         2005-05-24 22:54:33    1525    459         2005-05-28 19:40:33
3         2005-05-24 23:03:39    1711    408         2005-06-01 22:12:39
4         2005-05-24 23:04:41    2452    333         2005-06-03 01:43:41
5         2005-05-24 23:05:21    2079    222         2005-06-02 04:33:21

Quais tabelas estão no meu banco?

PostgreSQL:

SELECT * 
FROM pg_catalog.pg_tables
;

schemaname     tablename     tableowner 
public         address       postgres
public         actor         postgres
public         film_actor    postgres
public         language      postgres 
...            ...           ...

Quais tabelas estão no meu banco?

PostgreSQL:

SELECT * 
FROM pg_catalog.pg_tables
WHERE schema_name = 'public;

schemaname     tablename     tableowner 
public         address       postgres
public         actor         postgres
public         film_actor    postgres
public         language      postgres
...            ...           ...

Quais tabelas estão no meu banco?

PostgreSQL:

SELECT * FROM pg_catalog.pg_tables;

SQL Server - TSQL:

SELECT * FROM INFORMATION_SCHEMA.TABLES;

MySQL:

SHOW TABLES;

...

Encontre as tabelas de que você precisa!

Aplicando SQL a Problemas do Mundo Real