oracle判断查询结果是否为空

 1     declare
 2         cnta int;
 3     begin
 4         select count(*) into cnta from AS_SPJG where spid = :new.spid;
 5         if cnta = 0 then
 6             INSERT INTO AS_SPJG(SPID,
 7                                 PRICE,
 8                                 PRICE1,
 9                                 REGION,
10                                 LASTTIME,
11                                 UP_STATUS)
12             select :new.spid,
13                    0,
14                    0,
15                    ‘‘,
16 
17                    to_char(sysdate, ‘YYYY-MM-DD HH24:MI:SS‘),
18                    0
19 
20             FROM dual a;
21         end if;
22     end;