The booked_tickets table that I have created to store the info of the tickets

CREATE TABLE BOOKED_TICKETS( 
PNR_NO  NUMBER PRIMARY KEY, 
USER_ID  NUMBER,
TRAIN_NO  NUMBER,
SOURCE   VARCHAR2(50),  
DESTINATION  VARCHAR2(50),  
DATE_OF_ARRIV  DATE,
DATE_OF_BOOKING  DATE,
STATUS   VARCHAR2(50),
NO_OF_SEATS NUMBER,
BOOKED_CLASS  VARCHAR2(50),
SEAT_NO   NUMBER);

The Available_seats table to store the info of the seats available for each of the available class.

AVAILABLE_SEATS:
CREATE TABLE AVAILABLE_SEATS(
TRAIN_NO  NUMBER PRIMARY KEY,
SLEEPER_SEATS   NUMBER,
ONE_TIER_SEATS  NUMBER,
TWO_TIER_SEATS  NUMBER,
THREE_TIER_SEATS NUMBER,
GENERAL_SEATS  NUMBER);

This is the Query where am facing issue to store the value of avail seats into variable.

create or replace trigger status_tgr
before insert on booked_tickets
for each row
follows tkt_capitalize_tgr
declare
availSeats int;
begin
select availSeats = sleeper_seats from AVAILABLE_SEATS where train_no = :new.train_no;
update AVAILABLE_SEATS set sleeper_seats = availSeats - (:new.no_of_seats) where train_no = (:new.train_no);
end;
/

Error

Error at line 4: PL/SQL: SQL Statement ignored

2. before insert on booked_tickets
3. for each row
4. follows tkt_capitalize_tgr
5. declare
6. availSeats int;

>Solution :

Check you tkt_capitalize_tgr trigger there might be some issue in that.