How to Sub Select in SQL

Question

I wonder if anyone can help me because I could not do the command sub select between two tables, someone could help me?

I need to pull the name of the book that’s on the table book along with the sales chart data.

Table vendas:

Table livros:

Answer 1

Answering your question:

What do you want is not subselect and yes JOIN.

Example of JOIN whereas your sale table will always have 1 book for sale:

SELECT * 
FROM VENDAS VD
INNER JOIN LIVROS LV ON LV.IDLIVRO = VD.IDLIVRO

Filtering some fields:

SELECT VD.IDVENDA, LV.TITULO, LV.PRECO
FROM VENDAS VD
JOIN LIVROS LV ON LV.IDLIVRO = VD.IDLIVRO

(In the examples see that I used INNER JOIN and JOIN. In this case it works the same way, because using only JOIN he assumes as if he were INNER.)

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Extra examples:

To bring ALL values of table VENDAS even though nay completed the field IDLIVRO on the table VENDAS, use the LEFT JOIN:

SELECT * 
FROM VENDAS VD
LEFT JOIN LIVROS LV ON LV.IDLIVRO = VD.IDLIVRO

To bring ALL values of table LIVROS even though nay completed the field IDLIVRO on the table VENDAS, use the RIGHT JOIN:

SELECT * 
FROM VENDAS VD
RIGHT JOIN LIVROS LV ON LV.IDLIVRO = VD.IDLIVRO

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Reference on JOINS it would be nice to see as an example:

Select only tuples from a table with JOIN

Answer 2

The Join would be a solution as mentioned above, you can also do the following:

select * from Vendas
where idlivro in (
  select idlivro from livros where idgenero = 1
);