3

私は次の 2 つのテーブルを持っています。

 Id | Persons               PersonId | Field  | Value         
----+-------------         ----------+--------+-----------
 1  | Peter                      1   | City   | New York 
 2  | Jane                       1   | Age    | 26
                                 2   | City   | New York
                                 2   | Age    | 50
  1. age > 25 and city = 'New York'person with without groupingor pivotingthe table のような SQL クエリで検索条件を適用できますか。
  2. パフォーマンスのオーバーヘッドを最小限に抑えて検索基準を適用する最良の方法は何ですか。
4

3 に答える 3

2 
SELECT key1.PersonId 
FROM KeyValue key1
    INNER JOIN KeyValue key2 ON key1.PersonId = key2.PersonId
WHERE key1.[Field] = 'Age' and key1.[Value] > 25
    AND key2.[Field] = 'City' and key2.[Value] = 'New York'

アップデート

いくつかのテストを行ったところ、INNER JOIN は十分に高速に見えます。ここで結果とテストスクリプト

SET NOCOUNT ON 
SET STATISTICS IO ON

CREATE TABLE KeyValue (
    ID INT NOT NULL IDENTITY CONSTRAINT [PK_KeyValue] PRIMARY KEY CLUSTERED
    ,PersonId INT NOT NULL
    ,Field varchar(30) NOT NULL
    ,Value varchar(255) NOT NULL
    ,CONSTRAINT UQ__KeyValue__PersonId_Field UNIQUE (PersonId, Field)
)
GO
--INSERT INTO KeyValue 500K "users", 4 "Fields" - 2M rows

CREATE NONCLUSTERED INDEX [IX__KeyValue__Field_Value_ID]
ON [dbo].[KeyValue] ([Field],[Value]) INCLUDE ([PersonId])
GO

select PersonId from (
    select PersonId, ROW_NUMBER() OVER (PARTITION BY PersonId ORDER BY PersonId) RowNumber from (
        select PersonId from KeyValue where [Field] = 'Age' and [Value] > 25 union all
        select PersonId from KeyValue where [Field] = 'City' and [Value] = 'Sydney' union all
        select PersonId from KeyValue where [Field] = 'Email' and [Value] = 'xxxxx@gmail.com' union all
        select PersonId from KeyValue where [Field] = 'Name' and [Value] = 'UserName' 
    ) x
) y where RowNumber = 4
--Table 'KeyValue'. Scan count 20, logical reads 1510, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
--Table 'Worktable'. Scan count 0, logical reads 0, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.

select PersonId from (
        select PersonId from KeyValue where [Field] = 'Age' and [Value] > 25 union all
        select PersonId from KeyValue where [Field] = 'City' and [Value] = 'Sydney' union all
        select PersonId from KeyValue where [Field] = 'Email' and [Value] = 'xxxxx@gmail.com' union all
        select PersonId from KeyValue where [Field] = 'Name' and [Value] = 'UserName' 
) x GROUP by PersonId
HAVING COUNT(*) = 4
--Table 'Worktable'. Scan count 0, logical reads 0, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
--Table 'KeyValue'. Scan count 4, logical reads 1377, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.

SELECT key1.PersonId 
FROM KeyValue key1
    INNER JOIN KeyValue key2 ON key1.PersonId = key2.PersonId
    INNER JOIN KeyValue key3 ON key1.PersonId = key3.PersonId
    INNER JOIN KeyValue key4 ON key1.PersonId = key4.PersonId
WHERE key1.[Field] = 'Age' and key1.[Value] > 25
    AND key2.[Field] = 'City' and key2.[Value] = 'Sydney'
    AND key3.[Field] = 'Email' and key3.[Value] = 'xxxxx@gmail.com' 
    AND key4.[Field] = 'Name' and key4.[Value] = 'UserName' 
-- Table 'KeyValue'. Scan count 1, logical reads 21, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.

SET STATISTICS IO OFF
GO
于 2013-11-07T09:45:17.737 に答える
0

あなたの質問が正しいことを理解していれば、次のように機能します。

SELECT 
  one.* 
FROM table1 AS one
INNER JOIN table2 AS two1 ON one.Id = two1.PersonId
INNER JOIN table2 AS two2 ON one.Id = two2.PersonId
WHERE (two1.field = 'age' AND two1.value > 25) 
AND (two2.field = 'city' AND two2.value = 'New York')

幸運を！

于 2013-11-07T09:42:56.820 に答える