[英]Distinct rows get from a column. Oracle
我想基於運算符顯示不同的行。 喜歡
$query = oci_parse($con, "SELECT POST.*, USER_LOGIN.*, STATION.*, ROLE.*
FROM USER_LOGIN
INNER JOIN STATION ON USER_LOGIN.S_ID = STATION.S_ID
INNER JOIN POST ON USER_LOGIN.USER_ID = POST.USER_ID
INNER JOIN ROLE ON USER_LOGIN.ROLE_ID = ROLE.ROLE_ID
WHERE ROLE_NAME = 'Operator' ");
任何幫助,將不勝感激。
我現在得到以下錯誤。 我不知道這是怎么回事。
Error: ORA-00936: missing expression
$query = oci_parse($con,"SELECT * FROM
(SELECT POST.*, USER_LOGIN.*, STATION.*, ROLE.*, IR.*,
row_number() over(PARTITION BY ROLE_NAME ORDER BY ROLE_NAME) AS seqnum
FROM USER_LOGIN
INNER JOIN
STATION
ON USER_LOGIN.PS_ID = STATION.PS_ID
INNER JOIN
POST
ON USER_LOGIN.USER_ID = POST.USER_ID
INNER JOIN
ROLE
ON USER_LOGIN.ROLE_ID = ROLE.ROLE_ID
INNER JOIN
IR
ON USER_LOGIN.USER_ID = IR.USER_ID
WHERE ROLE_NAME = 'Operator') AS t
WHERE t.seqnum = 1");
我的猜測是您想指定特定的列並使用distinct
(或group by
):
SELECT DISTINCT operator, cnic, station
FROM USER_LOGIN INNER JOIN
STATION
ON USER_LOGIN.S_ID = STATION.S_ID INNER JOIN
POST
ON USER_LOGIN.USER_ID = POST.USER_ID INNER JOIN
ROLE
ON USER_LOGIN.ROLE_ID = ROLE.ROLE_ID
WHERE ROLE_NAME = 'Operator';
編輯:
如果要任意行,請執行以下操作:
SELECT *
FROM (SELECT POST.*, USER_LOGIN.*, STATION.*, ROLE.*,
row_number() over (partition by operator, cnic, station order by operator) as seqnum
FROM USER_LOGIN INNER JOIN
STATION
ON USER_LOGIN.S_ID = STATION.S_ID INNER JOIN
POST
ON USER_LOGIN.USER_ID = POST.USER_ID INNER JOIN
ROLE
ON USER_LOGIN.ROLE_ID = ROLE.ROLE_ID
WHERE ROLE_NAME = 'Operator'
) t
WHERE seqnum = 1;
row_number()
函數枚舉組中的行。 每個組都從1開始。分組是通過partition by
定義的,因此具有operator
, cnic
和station
相同值的行將在分組中。 order by
指定組中數字的順序。 這里為組使用一個常量,因此它是任意的。 最后一步是where seqnum = 1
,它從每個分組中選擇一行。
來自: http : //docs.oracle.com/cd/B28359_01/server.111/b28286/statements_10002.htm#SQLRF55166
如果希望數據庫僅返回所選的每組重復行的一個副本,則指定DISTINCT或UNIQUE。
像這樣更新您的代碼:
$query = oci_parse($con, "SELECT DISTINCT POST.*, USER_LOGIN.*, STATION.*, ROLE.*
FROM USER_LOGIN
INNER JOIN STATION ON USER_LOGIN.S_ID = STATION.S_ID
INNER JOIN POST ON USER_LOGIN.USER_ID = POST.USER_ID
INNER JOIN ROLE ON USER_LOGIN.ROLE_ID = ROLE.ROLE_ID
WHERE ROLE_NAME = 'Operator' ");
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