Most of the stored programs you write will include one or more parameters. Parameters make stored programs much more flexible and therefore more useful. Next, let’s create a stored procedure that accepts parameters.
The stored procedure shown in Figure 2-6 accepts an integer
calculates the square root of that number. The resulting number is
returned as a result set.
Place parameters within parentheses that are located immediately
after the name of the stored procedure. Each parameter has a name, a
data type, and, optionally, a mode. Valid modes are
INOUT (read-write), and
OUT (write-only). No parameter mode appears
in Figure 2-6, because
IN is the default and this is an
We’ll take a closer look at parameter modes following this example.
In addition to the parameter, this stored procedure introduces two other features of MySQL stored programs:
A statement used to create local variables for use in the
stored program. In this case, we create a floating-point number
A statement used to assign a value to a variable. In this case, we assign the square root of our input parameter (using ...