Question

I would like to know if it is possible to have this kind of schema:

Table 1:

Field1 | Field4 | Field3
Field1 | Field4 | Field3 
Field1 | Field4 | Field3

Table 2:

Field4 | Field5(Number of Field3)

To explain the schema, my tables have a similar field, (number4)

And my real question is:

Can I have a dynamic database where the field5 would be the count of field 3 where Table1.field4 = Table2.field4, or should I change it by hand with PHP?

Edit: “Can you provide some example data for this schema? (And perhaps some more meaningful names.)”

Table: prod
Product | Description | nbOfreview
Product | Description | nbOfreview

Table: Reviews
Review | Description | Product

Answer 1

You don’t need an extra table.
You can use a view.

e.g:

CREATE VIEW v_data AS
SELECT field4, COUNT(field3) F_COUNT
  FROM <YOUR-TABLE>
GROUP BY  field4