如何用主游标数据打开多个游标
How to open multiple cursors with main cursor data
我正在尝试从另一个存储过程 return 中读取存储过程中的游标,并希望通过遍历主游标数据来写入多个输出游标。
-- TYPE myCursorType IS REF CURSOR;
PROCEDURE prcgetalldetails (
incustomernumber IN customer.customer_number%TYPE,
accountdetailscur OUT pkgaccount.curaccountdetailstype,
fundscur OUT mycursortype,
otherdetailscur OUT mycursortype
) IS
localaccountdetails pkgaccount.curinvestmentaccount;
outcfunds curinvestmentaccount;
accountdetails pkgaccount.curaccountdetailstype%rowtype;
BEGIN
pkgaccount.accountdetails(incustomernumber,localaccountdetails);
LOOP
FETCH localaccountdetails INTO accountdetails;
EXIT WHEN localaccountdetails%notfound;
dbms_output.put_line(localaccountdetails.accountname
|| ','
|| localaccountdetails.accountnumber);
-- I have to return the 'accountdetailscur' as well,before that I have to loop through it and return remaining data as well
-- Based on account number I have to execute other queries and fetch other details and give those cursors back
OPEN fundscur FOR
SELECT
fundname,
fundid,
fundbalance
FROM
fundstable
WHERE
accountnumber = localaccountdetails.accountnumber;
OPEN otherdetailscur FOR
SELECT
col1,
col2
FROM
othertable
WHERE
accountnumber = localaccountdetails.accountnumber;
END LOOP;
END;
由于我在循环中打开游标,它 return 只会显示 localaccountdetails 游标的最后一行详细信息。我不确定如何使用 BUILK COLLECT 来收集所有内容并在其上循环。
而且我不知道如何return localaccountdetails 作为 OUT 数据并循环获取剩余数据。
您可以使用游标表达式将一个游标嵌套在另一个游标中。这是以下形式:
select cursor ( select ... ) from ...
所以你可以这样做:
create table par ( pk primary key ) as
select level pk
from dual
connect by level <= 5;
create table chd as
select r.c1 pk, par.pk fk
from par, lateral (
select level c1 from dual
connect by level <= pk
) r;
select pk,
cursor (
select * from chd c
where par.pk = c.fk
)
from par;
declare
cursor cur is
select pk,
cursor (
select * from chd c
where par.pk = c.fk
)
from par;
pk integer;
chd_cur sys_refcursor;
type chd_arr is table of chd%rowtype
index by pls_integer;
chd_recs chd_arr;
begin
open cur;
loop
fetch cur into pk, chd_cur;
exit when cur%notfound;
fetch chd_cur bulk collect into chd_recs;
dbms_output.put_line (
'Fetched ' || pk || ' child rows ' || chd_recs.count
);
end loop;
close cur;
end;
/
Fetched 1 child rows 1
Fetched 2 child rows 2
Fetched 3 child rows 3
Fetched 4 child rows 4
Fetched 5 child rows 5
请注意,这意味着您正在滚动自己的嵌套循环连接。除非你真的 需要控制客户端从 child/inner table 中获取多少行,否则我会将其设为连接。
如果要确保从父 table 获得一行,可以将内部 table 的行聚合到 JSON 或嵌套 table,例如:
select par.pk,
json_arrayagg (
json_object ( chd.* )
)
from par
join chd
on par.pk = chd.fk
group by par.pk;
PK JSON_ARRAYAGG(JSON_OBJECT(CHD.*))
1 [{"PK":1,"FK":1}]
2 [{"PK":1,"FK":2},{"PK":2,"FK":2}]
3 [{"PK":1,"FK":3},{"PK":3,"FK":3},{"PK":2,"FK":3}]
4 [{"PK":1,"FK":4},{"PK":4,"FK":4},{"PK":3,"FK":4},{"PK":2,"FK":4}]
5 [{"PK":1,"FK":5},{"PK":5,"FK":5},{"PK":4,"FK":5},{"PK":3,"FK":5},{"PK":2,"FK":5}]
我正在尝试从另一个存储过程 return 中读取存储过程中的游标,并希望通过遍历主游标数据来写入多个输出游标。
-- TYPE myCursorType IS REF CURSOR;
PROCEDURE prcgetalldetails (
incustomernumber IN customer.customer_number%TYPE,
accountdetailscur OUT pkgaccount.curaccountdetailstype,
fundscur OUT mycursortype,
otherdetailscur OUT mycursortype
) IS
localaccountdetails pkgaccount.curinvestmentaccount;
outcfunds curinvestmentaccount;
accountdetails pkgaccount.curaccountdetailstype%rowtype;
BEGIN
pkgaccount.accountdetails(incustomernumber,localaccountdetails);
LOOP
FETCH localaccountdetails INTO accountdetails;
EXIT WHEN localaccountdetails%notfound;
dbms_output.put_line(localaccountdetails.accountname
|| ','
|| localaccountdetails.accountnumber);
-- I have to return the 'accountdetailscur' as well,before that I have to loop through it and return remaining data as well
-- Based on account number I have to execute other queries and fetch other details and give those cursors back
OPEN fundscur FOR
SELECT
fundname,
fundid,
fundbalance
FROM
fundstable
WHERE
accountnumber = localaccountdetails.accountnumber;
OPEN otherdetailscur FOR
SELECT
col1,
col2
FROM
othertable
WHERE
accountnumber = localaccountdetails.accountnumber;
END LOOP;
END;
由于我在循环中打开游标,它 return 只会显示 localaccountdetails 游标的最后一行详细信息。我不确定如何使用 BUILK COLLECT 来收集所有内容并在其上循环。
而且我不知道如何return localaccountdetails 作为 OUT 数据并循环获取剩余数据。
您可以使用游标表达式将一个游标嵌套在另一个游标中。这是以下形式:
select cursor ( select ... ) from ...
所以你可以这样做:
create table par ( pk primary key ) as
select level pk
from dual
connect by level <= 5;
create table chd as
select r.c1 pk, par.pk fk
from par, lateral (
select level c1 from dual
connect by level <= pk
) r;
select pk,
cursor (
select * from chd c
where par.pk = c.fk
)
from par;
declare
cursor cur is
select pk,
cursor (
select * from chd c
where par.pk = c.fk
)
from par;
pk integer;
chd_cur sys_refcursor;
type chd_arr is table of chd%rowtype
index by pls_integer;
chd_recs chd_arr;
begin
open cur;
loop
fetch cur into pk, chd_cur;
exit when cur%notfound;
fetch chd_cur bulk collect into chd_recs;
dbms_output.put_line (
'Fetched ' || pk || ' child rows ' || chd_recs.count
);
end loop;
close cur;
end;
/
Fetched 1 child rows 1
Fetched 2 child rows 2
Fetched 3 child rows 3
Fetched 4 child rows 4
Fetched 5 child rows 5
请注意,这意味着您正在滚动自己的嵌套循环连接。除非你真的 需要控制客户端从 child/inner table 中获取多少行,否则我会将其设为连接。
如果要确保从父 table 获得一行,可以将内部 table 的行聚合到 JSON 或嵌套 table,例如:
select par.pk,
json_arrayagg (
json_object ( chd.* )
)
from par
join chd
on par.pk = chd.fk
group by par.pk;
PK JSON_ARRAYAGG(JSON_OBJECT(CHD.*))
1 [{"PK":1,"FK":1}]
2 [{"PK":1,"FK":2},{"PK":2,"FK":2}]
3 [{"PK":1,"FK":3},{"PK":3,"FK":3},{"PK":2,"FK":3}]
4 [{"PK":1,"FK":4},{"PK":4,"FK":4},{"PK":3,"FK":4},{"PK":2,"FK":4}]
5 [{"PK":1,"FK":5},{"PK":5,"FK":5},{"PK":4,"FK":5},{"PK":3,"FK":5},{"PK":2,"FK":5}]