Fixed-size lvarchar host variables

The following figure shows how to use a fixed-size lvarchar host variable to insert and select data in the circle_col column of the circle_tab table (see Creating a column of the circle opaque data type).
Figure 1: Accessing the external format of the circle opaque data type
EXEC SQL BEGIN DECLARE SECTION;
   lvarchar 'circle' lv_circle[30];
   char *x_coord;
EXEC SQL END DECLARE SECTION;

/* Insert a new circle_tab row with a literal opaque
 * value */
EXEC SQL insert into circle_tab
   values ('(3.00, 2.00, 11.5)');

/* Insert data into column circle of table circle_tab using an lvarchar host
 * variable */
strcpy(lv_circle, "(1.00, 17.00, 15.25)"); 
EXEC SQL insert into circle_tab values (:lv_circle);

/* Select column circle in circle_tab from into an lvarchar host variable
 */
EXEC SQL select circle_col into :lv_circle
   from circle_tab
   where radius(circle_col) = 15.25;