Question

I have the follow query:

SELECT pro.* 
  FROM tb_AutProposta pro, tb_AutParcelamento par 
 WHERE pro.id = par.id

But, want to limit each tb_AutParcelamento to 1. Tried “Subselect”, but without success.

The table pro is an contract and par is the parcels of this contract. For each contract, is generated n parcels, and, for each parcel is generated a due date, and I need to know the last due date for each contract.

Any idea?

Answer 1

I just made up some field names because we don’t know your exact table structure.

This query works under the assumptions:

• you want the latest (“highest”) parcel due date for each related contract
• you have fields for due_date and pro_id in your parcel table. (tb_AutParcelamento.pro_id being a foreign key to the tb_AutProposta.id)
• i made up pro_id because i assume the condition pro.id = par.id is wrong, when the id fields in both tables are auto increment values and the primary key in each table.

SELECT pro.*, MAX(par.due_date) as latest_due_date
FROM tb_AutProposta pro
LEFT JOIN tb_AutParcelamento par
    ON pro.id = par.pro_id
GROUP BY pro.id