UltraLite User's Guide
  The Embedded SQL Interface
    Fetching data

Fetching one row

A single row query retrieves at most one row from the database. A single-row query SELECT statement may have an INTO clause following the select list and before the FROM clause. The INTO clause contains a list of host variables to receive the value for each select list item. There must be the same number of host variables as there are select list items. The host variables may be accompanied by indicator variables to indicate NULL results.

When the SELECT statement is executed, the database server retrieves the results and places them in the host variables.

• If the query selects more than one row, the database server returns the SQLE_TOO_MANY_RECORDS error.

• If the query selects no rows, the SQLE_NOTFOUND warning is returned.

Errors and warnings are returned in the SQLCA structure, as described in The SQL Communication Area.

Example 

For example, the following code fragment returns 1 if a row from the employee table is successfully fetched, 0 if the row doesn't exist, and -1 if an error occurs.

EXEC SQL BEGIN DECLARE SECTION;
   long int    emp_id;
   char        name[41];
   char        sex;
   char        birthdate[15];
   short int   ind_birthdate;
EXEC SQL END DECLARE SECTION;
int find_employee( long employee )
{
   emp_id = employee;
   EXEC SQL   SELECT emp_fname || ' ' || emp_lname,
         sex, birth_date
      INTO :name, :sex, birthdate:ind_birthdate
      FROM "DBA".employee
      WHERE emp_id = :emp_id;
   if( SQLCODE == SQLE_NOTFOUND ) {
      return( 0 ); /* employee not found */
   } else if( SQLCODE < 0 ) {
      return( -1 ); /* error */
   } else {
      return( 1 ); /* found */
   }
}