我的程序似乎有问题。它用于搜索并且它正确地获得搜索但是返回了相同的答案太多次以至于我得到了耗尽内存的致命错误。这是我的代码：
FUNCTION pet_search(PETTYPE in VARCHAR2, BREED in VARCHAR2, COLOR in VARCHAR2, PETSIZE in VARCHAR2, TS in VARCHAR2, ENERGY in VARCHAR2, SPACE in VARCHAR2)
RETURN SYS_REFCURSOR
IS
pet_search_result SYS_REFCURSOR;
type_id NUMBER;
breed_id NUMBER;
color_id NUMBER;
size_id NUMBER;
TS_id NUMBER;
energy_id NUMBER;
space_id NUMBER;
BEGIN
select TP.pet_type_code into type_id
from dbadmin.petType TP
where TP.pet_type_name = PETTYPE;
select B.pet_race_code into breed_id
from dbadmin.petRace B
where B.pet_race_name = BREED;
select PC.pet_color_code into color_id
from dbadmin.PetColor PC
where PC.pet_color = COLOR;
select PS.pet_size_code into size_id
from dbadmin.PetSize PS
where PS.pet_size = PETSIZE;
select LS.pet_learn_code into TS_id
from dbadmin.petlearningskill LS
where LS.pet_learn_skill = TS;
select EN.pet_energy_code into energy_id
from dbadmin.petEnergy EN
where EN.pet_energy_level = ENERGY;
select SP.pet_space_code into space_id
from dbadmin.petSpace SP
where SP.pet_space = SPACE;
OPEN pet_search_result FOR select pet_type_name, pet_race_name, pet_cond_name, pet_energy_level, pet_learn_skill, vet_name, person_name, petlocation, petnotes, petabandondescription, pet_space, pet_treatment, pet_color, pet_sickness_name, pet_med_name
from pet, pettype, petrace, petCondition, petSize,petEnergy, petlearningskill, veterinary, person, petSpace, pettreatments, petcolor, petsickness, petmedicine
WHERE pettype.pet_type_code = type_id
AND petrace.pet_race_code = breed_id
AND pet.pet_color_code = color_id
AND pet.pet_size_code = size_id
AND pet.pet_learn_code = TS_id
AND pet.pet_energy_code = energy_id
AND pet.petspace_id = space_id;
RETURN pet_search_result;
EXCEPTION
WHEN NO_DATA_FOUND THEN
RETURN null;
END;
END pet_search_package;
答案 0 :(得分：0)
问题似乎出现在select查询中，如果你的where子句确实满足所有条件，那么由于 join ，行将被复制。 请参阅下面的示例，说明问题以及解决方法。
select pet_type_name, pet_race_name, pet_cond_name, pet_energy_level, pet_learn_skill, vet_name, person_name, petlocation, petnotes, petabandondescription, pet_space, pet_treatment, pet_color, pet_sickness_name, pet_med_name
from pet, pettype, petrace, petCondition, petSize,petEnergy, petlearningskill, veterinary, person, petSpace, pettreatments, petcolor, petsickness, petmedicine
WHERE pettype.pet_type_code = type_id
AND petrace.pet_race_code = breed_id
AND pet.pet_color_code = color_id
AND pet.pet_size_code = size_id
AND pet.pet_learn_code = TS_id
AND pet.pet_energy_code = energy_id
AND pet.petspace_id = space_id;
例如，这里有两个表emp和dept，
SQL> select * from emp;
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
---------- ---------- --------- ---------- --------- ---------- ---------- ----------
7369 SMITH CLERK 7902 17-DEC-80 800 20
7499 ALLEN SALESMAN 7698 20-FEB-81 1600 300 30
7521 WARD SALESMAN 7698 22-FEB-81 1250 500 30
7566 JONES MANAGER 7839 02-APR-81 2975 20
7654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400 30
7698 BLAKE MANAGER 7839 01-MAY-81 2850 30
7782 CLARK MANAGER 7839 09-JUN-81 2450 10
7788 SCOTT ANALYST 7566 19-APR-87 3000 20
7839 KING PRESIDENT 17-NOV-81 5000 10
7844 TURNER SALESMAN 7698 08-SEP-81 1500 0 30
7876 ADAMS CLERK 7788 23-MAY-87 1100 20
7900 JAMES CLERK 7698 03-DEC-81 950 30
7902 FORD ANALYST 7566 03-DEC-81 3000 20
7934 MILLER CLERK 7782 23-JAN-82 1300 10
14 rows selected.
SQL> select * from dept;
DEPTNO DNAME LOC
---------- -------------- -------------
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON
如果满足where子句中的所有条件，则此查询将仅返回1行。
SQL> select a.empno,b.deptno,a.ename from emp a,dept b where a.empno=7369 and b.deptno=20;
EMPNO DEPTNO ENAME
---------- ---------- ----------
7369 20 SMITH
如果条件where子句不完全匹配，或者差异数量较少，它将返回重复项。
SQL> select a.empno,b.deptno,a.ename from emp a,dept b where a.empno=7369 ;
EMPNO DEPTNO ENAME
--------- ---------- ----------
7369 10 SMITH
7369 20 SMITH
7369 30 SMITH
7369 40 SMITH
如果你在这些表之间有引用，那么建议在where子句中使用它然后比较
答案 1 :(得分：0)
在主查询的FROM子句中包含十几个引用数据表。但是，您不会限制它们，以便它们返回所有行。此外，您不能将他们加入数据表PET。这会产生交叉连接或笛卡尔积，它为这些表中的每个记录组合生成一行 。
以下是您的查询重写，以便明确发生了什么，以及它是否正常运行：
OPEN pet_search_result FOR
select pet_type_name
, pet_race_name
, pet_cond_name
, pet_energy_level
, pet_learn_skill
, vet_name
, person_name
, petlocation
, petnotes
, petabandondescription
, pet_space
, pet_treatment
, pet_color
, pet_sickness_name
, pet_med_name
from pet
join pettype TP
on pet.pet_type_code = TP.pet_type_code
join petrace B
on pet.pet_race_code = B.pet_race_code
join petSize PS
on pet.pet_size_code = PS.pet_size_code
join petEnergy EN
on pet.pet_energy_code = EN.pet_energy_code
join petcolor pc
on pet.pet_color_code = PC.pet_color_code
join petlearningskill LS
on pet.pet_learn_code = LS.pet_learn_code
join petSpace SP
on pet.petspace_id = SP.pet_space_code
where TP.pet_type_name = PETTYPE
and B.pet_race_name = BREED
and PS.pet_size = PETSIZE
and PC.pet_color = COLOR
and EN.pet_energy_level = ENERGY
and LS.pet_learn_skill = TS
and SP.pet_space = SPACE;
以这种方式编写意味着您可以在程序开始时丢弃所有这些小视图。
我省略了下表。您还没有提供限制它们的任何条件，因此它们不会影响结果集。
pettreatments petCondition petsickness petmedicine veterinary person