PROCEDURE DELETE_X1
IS
v_emp_unum VARCHAR2 (25);
BEGIN
/*FOR rec
IN (SELECT l2.*,
row_number ()
OVER (PARTITION BY case_uid,nvl(min_eff_date, eff_begin_date)
ORDER BY case_uid,nvl(min_eff_date, eff_begin_date))
rw,
ROWID rid
FROM (SELECT l1.*,
MIN (
CASE
WHEN eff_end_date = next_begin - 1
THEN
eff_begin_date
END)
OVER (PARTITION BY case_uid)
min_eff_date,
MAX (
CASE
WHEN previous_end <>
TO_DATE ('12/31/9999',
'mm/dd/yyyy')
AND previous_end + 1 = eff_begin_date
THEN
eff_end_date
END)
OVER (PARTITION BY case_uid)
max_end_date
FROM (SELECT GT.*,
LEAD (
EFF_begin_DATE)
OVER (PARTITION BY CASE_UID
ORDER BY EFF_BEGIN_DATE)
next_begin,
LAG (
EFF_end_DATE)
OVER (PARTITION BY CASE_UID
ORDER BY EFF_BEGIN_DATE)
previous_end
FROM TABLE_OUTPUT GT
WHERE SRC = 'ERICSSON' AND STATUS_CODE = 'X1') l1)
l2)*/
FOR rec
IN (SELECT l2.*,
ROW_NUMBER ()
OVER (PARTITION BY case_uid, min_eff_date, max_end_date
ORDER BY case_uid, min_eff_date, max_end_date)
rw,
ROWID rid
FROM (SELECT l1.*,
(MAX (
start_at)
OVER (
PARTITION BY case_uid
ORDER BY EFF_BEGIN_DATE
ROWS UNBOUNDED PRECEDING))
min_eff_date,
(MIN (
break_at)
OVER (
PARTITION BY case_uid
ORDER BY EFF_BEGIN_DATE
ROWS BETWEEN CURRENT ROW
AND UNBOUNDED FOLLOWING))
max_end_date
FROM (SELECT GT.*,
(CASE
WHEN LAG (
EFF_end_DATE)
OVER (
PARTITION BY CASE_UID
ORDER BY EFF_BEGIN_DATE) =
EFF_BEGIN_DATE
- 1
THEN
NULL
ELSE
EFF_BEGIN_DATE
END)
start_at,
(CASE
WHEN LEAD (
EFF_BEGIN_DATE)
OVER (
PARTITION BY case_uid
ORDER BY EFF_BEGIN_DATE) =
CASE
WHEN EFF_end_DATE <>
TO_DATE (
'12/31/9999',
'mm/dd/yyyy')
THEN
EFF_end_DATE
+ 1
ELSE
EFF_end_DATE
END
THEN
NULL
ELSE
EFF_end_DATE
END)
break_at
FROM TABLE_OUTPUT GT
WHERE SRC = 'ERICSSON' AND STATUS_CODE = 'X1') l1)
l2)
代码的一部分被注释掉了。
注释掉代码输出
OFF TIME 1/1/2017 1/7/2017 X1
OFF TIME 1/8/2017 2/1/2017 X1
新代码输出
OFF TIME 1/1/2017 2/1/2017 X1
NORMAL 2/2/2017 2/2/2017 AB
OFF TIME 2/20/2017
LAG功能用于访问前一行的数据。 LEAD函数用于从结果集中向下的行返回数据。 集合函数MIN，MAX
我对代码流感到困惑。 我无法理解整个代码请解释代码的逻辑