Exercise 3: Creating Distinct Data Types and Casts, continued

The Mercury DataBlade module uses two user-defined routines to prevent users from entering values below absolute zero in the data types CTemp and FTemp. In this DataBlade module, you implement Assign() functions for the FTemp and CTemp data types. The C functions that implement the Assign() functions are named FTempAssign() and CTempAssign(). The server calls the appropriate routine before it stores a value for either of the two temperature types.

Choose Edit

Insert

Routine and enter the following information, once for each routine, in the New Routine wizard.


Routine Property	FTempAssign Value	CTempAssign Value
Routine Name (SQL)	assign	assign
Return type	FTemp	CTemp
Statement Local Variable	No	No
Arguments	Name: temperature Type: FTemp Default: none	Name: temperature Type: CTemp Default: none
Language	C	C
Options for how the database server calls this routine (page 5)	Only the Routine does not accept NULL arguments check box should be checked; uncheck the Routine may return inconsistent check box.	Only the Routine does not accept NULL arguments check box should be checked; uncheck the Routine may return inconsistent check box.
Routine Name (C)	FTempAssign	CTempAssign
Shared object path	Default	Default
Behavior of routines	Routine is well-behaved	Routine is well-behaved
Special stack requirements	None	None
Cost	0	0
Related routines	None	None
Grant execute privileges	Grant execute privileges	Grant execute privileges

Choose Edit

Insert

Cast and enter the following information in the New Cast wizard.


Cast Property	decimal to temperature Value
Cast from type	decimal
Cast to type	temperature
Cast should be called for implicit type conversion	Yes
Cast requires a user defined cast support function	Yes
Support routine name is:	temperatureCast
Grant execute privileges	Grant execute privileges