Question

I need to create a view where I’ll list certain attributes. To be more specific:

Table Clientemp –

• contact

Table Cliente –

• name,
• address

I need to get into the Clientemp the name and address attribute from the table Cliente.
So far I have:

create view "Company Clients"
select client.name, cliente.address, clientemp.contact
from cliente, clientemp
insert into clientemp (select name, address from cliente)

Will this work? Any suggestion?

Answer 1

Basic VIEW DDL:

CREATE VIEW CompanyClients AS
SELECT {column list}
  FROM Clientemp T1
 INNER JOIN
     Cliente T2
         ON T1.{Key} = T2.{Key}
;

1. As you have written the SELECT the join will result in a CARTESIAN PRODUCT (CROSS JOIN)
   of the tables Clientemp and Cliente. Which will yield every possible combination of records between the two tables.

2. Proper syntax for an INSERT statement would be

   INSERT INTO {Target}
   SELECT {Column list} FROM {TableA} /* Optional Join conditions */;

3. Depending on the Database system your VIEW definition will likely
   not allow for an INSERT statement.

4. However, some database systems
   allow you to perform INSERTS through views if the underlying view
   targets a single table and is properly qualified with columns
   requiring a value to be present at the time of INSERT. (In
   other words all columns that do not have a DEFAULT value specified in
   the table definition.)