¶

SELECT opt_all_distinct selection
    INTO target_commalist
    table_exp
    with_opt_cursor_options_list
    ;

opt_all_distinct
	: /* empty */
	| ALL
	| DISTINCT
	;

with_opt_cursor_options_list
	: /* empty */
	| WITH opt_cursor_options_list
	;

cursor_option
	: EXCLUSIVE
	;

cursor_options_commalist
	: cursor_option
	| cursor_options_commalist ',' cursor_option
	;

opt_cursor_options_list
	: /* empty */
	| '(' cursor_options_commalist ')'
	;

cursor_def : DECLARE NAME CURSOR FOR query_exp
           | DECLARE NAME (DYNAMIC|KEYSET|STATIC) CURSOR FOR query_exp

open_statement
	: OPEN cursor opt_cursor_options_list
	;

fetch_statement : FETCH cursor INTO target_commalist
                | FETCH cursor (FIRST|NEXT|PREVIOUS|LAST) INTO target_commalist
                | FETCH cursor BOOKMARK scalar_exp INTO target_commalist

target_commalist
	: variable
	| target_commalist ',' variable
	;

close_statement
	: CLOSE cursor
	;

The open, fetch and close statements manipulate cursors in Virtuoso/PL statements. Cursors are declared with the declare cursor statement. The select into statement is a shorthand for a cursor declaration, open, fetch and close.

A forward-only cursor declaration is a declaration only and executing one does not take time. The open statement effectively starts the search associated with the forward-only cursor.

The forward-only cursor options used with open and select into allow controlling how the cursor sets locks on selected rows and how many rows it fetches at a time. The EXCLUSIVE option should be used if intending to update or delete a row in the cursor's evaluation. This causes selected rows to be locked with exclusive (write) locks.

The statements:

{
    DECLARE CR CURSOR FOR SELECT C_NAME FROM CUSTOMER WHERE C_ID = ID;
    OPEN CR;
    FETCH CR INTO NAME;
    CLOSE CR;
}

and

SELECT C_NAME INTO NAME FROM CUSTOMER WHERE C_ID = ID;

have the same effect.