Sql 具体化本身：具体化视图本身并不是视图——它们是派生表，过去被称为快照，这可能是一个更好的名称。 select A, B, C from aTbl, bTbl left join cTbl on bTbl.cTblID = cTbl.objectkey w

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具体化本身：具体化视图本身并不是视图——它们是派生表，过去被称为快照，这可能是一个更好的名称。

select A, B, C 
from aTbl, bTbl left join cTbl on bTbl.cTblID = cTbl.objectkey
where aTbl.objectkey = bTbl.parentkey

SELECT A, B, C 
FROM   aTbl, bTbl
LEFT JOIN cTbl ON 
  bTbl.cTblID = cTbl.objectkey
WHERE aTbl.objectkey = bTbl.parentkey
  AND aTbl.flag1 = :NUMBER

SELECT *
FROM
  (
  SELECT A, B, C, flag1
  FROM   aTbl, bTbl
  LEFT JOIN cTbl ON 
    bTbl.cTblID = cTbl.objectkey
  WHERE aTbl.objectkey = bTbl.parentkey
  )
WHERE flag1 = :NUMBER

/*
CREATE VIEW v_abc AS
SELECT A, B, C, flag1 
FROM   aTbl, bTbl
LEFT JOIN cTbl ON 
  bTbl.cTblID = cTbl.objectkey
WHERE aTbl.objectkey = bTbl.parentkey
*/

SELECT A, B, C
FROM v_abc
WHERE flag1 = :NUMBER

DECLARE cursor c (cpflag aTbl.flag1%TYPE )is select A, B, C from aTbl, bTbl, cTbl where aTbl.objectkey = bTbl.parentkey and bTbl.cTblID = cTbl.objectkey and aTbl.flag1 = cp_flag ; vtype c%rowtype; BEGIN open c(100); fetch c into vtype; close c; open c(200); fetch c into vtype; close c; END;