MarcoPolo - db_countrecords()

This function returns the number of records in a database.

Counting Records

In certain situations you may find it useful to size the database or to count the number of records it contains. The db_size() function returns the size. This function returns the database record count.

Syntax

db_countrecords(<conn>, <opts>)

• <conn> Defines the database connection.
• <opts> Defines additional options. For more information on the available options, see Options.

Options

This function only provides one additional option:

• :timeout Defines the timeout value in milliseconds. In the event that the operation takes longer than the allotted time, MarcoPolo sends an exit signal to the calling process.

Return Values

When this function is successful it returns the tuple {:ok, count}, where count is a non-negative integer indicating the number of records in the connected database. In the event that the function fails, it returns the tuple {:error, reason}, where the reason is the exception message the function receives.

Example

For instance, consider the use case of a logging operation. Whenever you connect to the database it logs the record count to the console.

@doc """ Open Database """
def connect() do

    # Log Operation
    IO.puts("Connecting to Database")

    # Connect to Database
    {:ok, conn} = MarcoPolo.start_link(
            user: "admin",
            password: "admin_passwd",
            connection: {:db, "blog"}) 

    # Log Number of Records
    count = MarcoPolo.db_countrecords(conn, {:timeout 5000})
    IO.puts("Record Count: #{count}")

    # Return Connection
    {:ok, conn}

end