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Jhonatan Valencia
Asked: 2020-10-11 10:41:44 +0800 CST 2020-10-11 10:41:44 +0800 CST

question with sql query

  • 772

well what happens is that I have a problem to consult a table, I have the typical products and category table where id_categoria the attribute that relates the tables would be

  1. what I can't do is bring me EVERYTHING from the products table

I don't know if it's because the tables are related

SELECT  *  FROM productos

and it doesn't work for me

I try to do the selectwithout the attribute id_categoriaand it works but I need the query with that value

Thank you very much for your help

sql

2 Answers

  1. Best Answer

    here several queries with only two tables where I have id_categoria in the products table:

      *******************
  *productos        *
  *******************
  *id               *
  *nombre           *
  *descripcion      * 
  *id_categoria     *
  *******************

  *******************
  *categorias       *
  *******************
  *id               *
  *nombre           * 
  *descripcion      *
  *******************

    fetch all the attributes of all the records of the products table:

    select * from productos

    fetch all products related to a certain category:

    select * from productos where id_categoria = 3

    fetch product names filtered by category name:

    select nombre from productos where id_categoria in ( select id from categorias where nombre like %hogar% )

    It may be that the one I used is not the structure of your tables, if you put your structure we could help you in a better way. We await your comments..

    • 2

  2. This can happen if you don't use aliases in the joins. because it can be a problem to return two columns with the same name.

    SELECT A.CATEGOTYID, A.CATEGORYNAME, B.PRODUCTNAME
FROM CATEGORY AS A
INNER JOIN PRODUCT AS B
ON A.CATEGORYID = B.CATEGORYID

    This is how it should work.

    • 1