Question

我首先尝试排序记录，然后区分它们（不同的PersonID，但通过获取整个行内容而不重复PersonID）在oracle上使用单个查询。

在示例中：按RecordType排序（p first）然后获取不同的PersonID列表
案例1的期望结果：

(1,'John', 'Doe', 2,'P' );
(2,'Scot', 'Mic', 1,'P' );

案例2的预期结果：

(1,'John', 'Doe', 1,'S' );  
(2,'Scot', 'Mic', 1,'P' )

SQL：

drop table test_records;

CREATE TABLE test_records
(
  PersonID int,
  LastName varchar(255),
  FirstName varchar(255),
  RecordId int,
  RecordType varchar(255)

); 

1 case:
insert into test_records values(1,'John', 'Doe', 1,'S' );  
insert into test_records values(1,'John', 'Doe', 2,'P' );
insert into test_records values(1,'John', 'Doe', 3,'S' );
insert into test_records values(1,'John', 'Doe', 4,'S' );
insert into test_records values(1,'John', 'Doe', 1,'S' );
insert into test_records values(2,'Scot', 'Mic', 1,'P' );


2 case:
insert into test_records values(1,'John', 'Doe', 1,'S' );  
insert into test_records values(1,'John', 'Doe', 2,'S' );
insert into test_records values(1,'John', 'Doe', 3,'S' );
insert into test_records values(1,'John', 'Doe', 4,'S' );
insert into test_records values(1,'John', 'Doe', 1,'S' );
insert into test_records values(2,'Scot', 'Mic', 1,'P' );

Answer 1

我认为分析row_number()电话是您正在寻找的

SELECT PersonID, LastName, FirstName, RecordId, RecordType
FROM   (SELECT PersonID, LastName, FirstName, RecordId, RecordType,
               ROW_NUMBER() OVER (PARTITION BY PersonID ORDER BY RecordType ASC) AS rn
        FROM   test_records) t
WHERE  rn = 1

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1 个答案: