FETCH with a Scroll Cursor
These Informix®
ESQL/C examples
illustrate the FETCH statement with a scroll cursor:
EXEC SQL fetch previous q_curs into :orders;
EXEC SQL fetch last q_curs into :orders;
EXEC SQL fetch relative -10 q_curs into :orders;
printf("Which row? ");
scanf("
EXEC SQL fetch absolute :row_num q_curs into :orders;
A scroll cursor can fetch any row in the active set, either by specifying an absolute row position or a relative offset. Use the following cursor-position options to specify a particular row that you want to retrieve.
- Keyword
- Effect
- NEXT
- Retrieves next row in active set
- PREVIOUS
- Retrieves previous row in active set
- PRIOR
- Retrieves previous row in active set (Synonymous with PREVIOUS.)
- FIRST
- Retrieves the first row in active set
- LAST
- Retrieves the last row in active set
- CURRENT
- Retrieves the current row in active set (the same row as returned by the previous FETCH statement from the scroll cursor)
- RELATIVE
- Retrieves nth row, relative to the current cursor position
in the active set, where position_num (or position_num_var) supplies n. A
negative value indicates the nth row prior to the current cursor
position. If position_num =
0
, the current row is fetched. - ABSOLUTE
- Retrieves nth row in active set, where row_position_var (or row_position)
= n . Absolute row positions are numbered from
1
.
Tip: Do not confuse row-position values
with rowid values. A rowid value is based on the position
of a row in its table and remains valid until the table is rebuilt.
A row-position value (a value that the ABSOLUTE keyword retrieves)
is the relative position of the row in the current active set of the
cursor; the next time the cursor is opened, different rows might be
selected.