Procedure CANCEL_BLOB
RDB$BLOB_UTIL.CANCEL_BLOB
immediately releases a temporary BLOB, like one created with BLOB_APPEND
.
If the same BLOB is used after cancel, an “invalid blob id” error will be raised.
-
BLOB
typeBLOB
CANCEL_BLOB
RDB$BLOB_UTIL.CANCEL_BLOB
immediately releases a temporary BLOB, like one created with BLOB_APPEND
.
If the same BLOB is used after cancel, an “invalid blob id” error will be raised.
BLOB
type BLOB
CLOSE_HANDLE
RDB$BLOB_UTIL.CLOSE_HANDLE
closes a BLOB handle opened with RDB$BLOB_UTIL.OPEN_BLOB
.
Handles which are not explicitly closed are closed automatically when the transaction ends.
HANDLE
type INTEGER NOT NULL
EXECUTE BLOCK
execute block returns (b blob)
as
begin
-- Create a BLOB handle in the temporary space.
b = rdb$blob_util.new_blob(false, true);
-- Add chunks of data.
b = blob_append(b, '12345');
b = blob_append(b, '67');
suspend;
end
EXECUTE BLOCK
execute block returns (s varchar(10))
as
declare b blob = '1234567';
declare bhandle integer;
begin
-- Open the BLOB and get a BLOB handle.
bhandle = rdb$blob_util.open_blob(b);
-- Get chunks of data as string and return.
s = rdb$blob_util.read_data(bhandle, 3);
suspend;
s = rdb$blob_util.read_data(bhandle, 3);
suspend;
s = rdb$blob_util.read_data(bhandle, 3);
suspend;
-- Here EOF is found, so it returns NULL.
s = rdb$blob_util.read_data(bhandle, 3);
suspend;
-- Close the BLOB handle.
execute procedure rdb$blob_util.close_handle(bhandle);
end
set term !;
execute block returns (s varchar(10))
as
declare b blob;
declare bhandle integer;
begin
-- Create a stream BLOB handle.
b = rdb$blob_util.new_blob(false, true);
-- Add data.
b = blob_append(b, '0123456789');
-- Open the BLOB.
bhandle = rdb$blob_util.open_blob(b);
-- Seek to 5 since the start.
rdb$blob_util.seek(bhandle, 0, 5);
s = rdb$blob_util.read_data(bhandle, 3);
suspend;
-- Seek to 2 since the start.
rdb$blob_util.seek(bhandle, 0, 2);
s = rdb$blob_util.read_data(bhandle, 3);
suspend;
-- Advance 2.
rdb$blob_util.seek(bhandle, 1, 2);
s = rdb$blob_util.read_data(bhandle, 3);
suspend;
-- Seek to -1 since the end.
rdb$blob_util.seek(bhandle, 2, -1);
s = rdb$blob_util.read_data(bhandle, 3);
suspend;
end!
set term ;!
create table t(b blob);
set term !;
execute block returns (bool boolean)
as
declare b blob;
begin
b = blob_append(null, 'writable');
bool = rdb$blob_util.is_writable(b);
suspend;
insert into t (b) values ('not writable') returning b into b;
bool = rdb$blob_util.is_writable(b);
suspend;
end!
set term ;!
RDB$PROFILER
A package with functions and procedures to run and control the profiler.
Note
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