創建視圖時，Oracle拋出SQL錯誤

Question

我正在嘗試在Oracle數據庫中創建視圖，但始終收到ORA-00907錯誤（缺少正確的括號）。 我的SQL如下：

CREATE VIEW my_view AS 
(
SELECT metadata.ID,metadata.Field1,metadata.Field2,metadata.Field3,metadata.Field4,attribute1.StrValue AS Attr1, attribute2.StrValue AS Attr2 
FROM metadata,data AS attribute1,data AS attribute2 
WHERE 
    (
    metadata.Type = 'TYPE1'
    ) 
AND 
    (
    metadata.ID = attribute1.ID AND attribute1.name = 'attr1'
    ) 
    AND 
    (
    metadata.ID = attribute2.ID AND attribute2.name = 'attr2'
    )
)

表元數據定義實體，數據定義這些實體的屬性。

這在MS SQL和MySQL中可以正常工作，但是我一直從Oracle收到上述錯誤。

與Oracle的合作時間不長，因此我對它的怪癖不甚了解。

Answer 1

CREATE VIEW my_view AS 
(
SELECT  metadata.ID,metadata.Field1,metadata.Field2,
        metadata.Field3,metadata.Field4,
        attribute1.StrValue AS Attr1, attribute2.StrValue AS Attr2 
FROM    metadata, data /* No AS here */ attribute1,
        data /* No AS here */ attribute2 
WHERE 
        (
        metadata.Type = 'TYPE1'
        ) 
AND 
        (
        metadata.ID = attribute1.ID AND attribute1.name = 'attr1'
        ) 
        AND 
        (
        metadata.ID = attribute2.ID AND attribute2.name = 'attr2'
        )
)

我刪除了data和attribute1之間的AS

Answer 2

既然您的括號都不是必需的，並且它們使閱讀代碼更加困難，那么為什么不刪除它們呢？

Answer 3

您需要在FROM子句中刪除AS。 Oracle允許使用可選的AS為列名加上別名，但不允許提供別名

SQL> ed
Wrote file afiedt.buf

  1  CREATE VIEW my_view AS
  2  (
  3  SELECT metadata.ID,metadata.Field1,metadata.Field2,metadata.Field3,metadata
.Field4,attribute1.StrValue AS Attr1, attribute2.StrValue AS Attr2
  4  FROM metadata,data attribute1,data attribute2
  5  WHERE
  6          (
  7          metadata.Type = 'TYPE1'
  8          )
  9  AND
 10          (
 11          metadata.ID = attribute1.ID AND attribute1.name = 'attr1'
 12          )
 13          AND
 14          (
 15          metadata.ID = attribute2.ID AND attribute2.name = 'attr2'
 16          )
 17* )
SQL> /

View created.

取決於所使用的工具，知道SQL * Plus可以准確地向您顯示語法錯誤發生的位置可能很有用-下面的代碼段顯示它反對AS關鍵字。

SQL> ed
Wrote file afiedt.buf

  1  CREATE VIEW my_view AS
  2  (
  3  SELECT metadata.ID,metadata.Field1,metadata.Field2,metadata.Field3,metadata
.Field4,attribute1.StrValue AS Attr1, attribute2.StrValue AS Attr2
  4  FROM metadata,data AS attribute1,data AS attribute2
  5  WHERE
  6          (
  7          metadata.Type = 'TYPE1'
  8          )
  9  AND
 10          (
 11          metadata.ID = attribute1.ID AND attribute1.name = 'attr1'
 12          )
 13          AND
 14          (
 15          metadata.ID = attribute2.ID AND attribute2.name = 'attr2'
 16          )
 17* )
SQL> /
FROM metadata,data AS attribute1,data AS attribute2
                   *
ERROR at line 4:
ORA-00907: missing right parenthesis

Answer 4

其他人指出您的FROM子句中的AS關鍵字是問題。 我建議以下內容作為更清晰，更易讀的同一語句版本：

create view my_view as 
select
  meta.id
 ,meta.field1
 ,meta.field2
 ,meta.field3
 ,meta.field4
 ,att1.strvalue as attr1
 ,att2.strvalue as attr2 
from
  metadata meta
 ,data att1
 ,data att2 
where meta.id = att1.id 
  and meta.id = att2.id 
  and meta.type = 'TYPE1'
  and att1.name = 'attr1'
  and att2.name = 'attr2'