Start Updating table in dbi perl

Updating table in dbi perl

Here’s one solution: The mathematics department is department #17 and has three members: Karl Gauss, Emmy Noether, and William Hamilton.

For example, the database engine may parse and understand the SQL and translate it into an internal format.

Since the query is the same every time, it’s wasteful to throw away this work when the function returns.

Each time we call method returns the number of rows of the database that were selected.

If no rows were selected, then there is nobody in the database with the last name that the user is looking for. We have to do this It prepares the query, executes it, and retrieves the result. Even though the function works correctly, it’s inefficient. Typically, preparing a query is a relatively expensive operation.

Some libraries, like Oracle’s, are very thin—they just send the query over to the network to the real database and let the giant expensive real database engine deal with it directly.

Other libraries will do more predigestion of the query, and more work afterwards to turn the data into a data structure.

As a result, all the important database systems support it in some fashion or another. For the details, go to any reasonable bookstore and pick up a SQL quick reference. You talk to some databases over the network and make requests of the database engine; other databases you talk to through files or something else.