I have a database containing two tables. An ON INSERT trigger in Table ITEMS is supposed to add the value of ITEMS.ITEMSIZE to STATS.SIZE 

The select statement below is the problem. How do I modify this to only get the ITEMSIZE of the current row being updated. BTW the STATS table only has a single row.

```
** Tables **

CREATE TABLE ITEMS (
    ID              ID NOT NULL /* ID = VARCHAR(36) NOT NULL */,
    EXPIRYTIME      EXPIRYTIME NOT NULL /* EXPIRYTIME = BIGINT NOT NULL */,
    ITEMSIZE        ITEMSIZE /* ITEMSIZE = BIGINT NOT NULL */,
    ACCESSCOUNT     ACCESSCOUNT DEFAULT 1 NOT NULL /* ACCESSCOUNT = INTEGER DEFAULT 1 NOT NULL */,
    LASTACCESSTIME  LASTACCESSTIME /* LASTACCESSTIME = TIMESTAMP NOT NULL */
);

CREATE TABLE STATS (
    INSTANCE            SMALLINT,
    SIZE                BIGINT DEFAULT 0,
    DISKCACHEITEMCOUNT  BIGINT DEFAULT 0,
    DISKCACHEHITS       BIGINT DEFAULT 0,
    DISKCACHEMISSES     BIGINT DEFAULT 0
);

```

\*\* Trigger \*\*

```
AS
DECLARE ITEM_SIZE bigint;
begin
SELECT ITEMSIZE FROM ITEMS INTO :ITEM_SIZE;
UPDATE STATS SET SIZE = SIZE  + :ITEM_SIZE WHERE INSTANCE = '0';
end

```