sql - sql 中前 10 行的复杂连接

Question

Table1:
Id  Word    Frequency
1   A   1
2   B   5


Table2:
Id  Word    SecondWord  SecondFrequency
1   A   A1      1           
2   A   A2      5
3   A   A3      10
4   A   A4      9
5   A   A5      20
6   B   B1      5
7   B   B2      8
8   B   B3      50
9   B   B4      40
10  B   B5      68

所需的输出 “Table2”中的前 3 条记录，按 SecondFrequency 描述排序 例如。

Word    Frequency   SecondWord  SecondFrequency
A   1       A5      20
A   1       A3      10
A   1       A4      9   
B   5       B5      68
B   5       B3      50
B   5       B4      40

如何获得所需的输出

Answer 1

  Use ROWNUMBER function based on second frequency for get you required result:

 CREATE TABLE #Table1(Id  TINYINT, Word VARCHAR(1),Frequency TINYINT)
 CREATE TABLE #Table2(Id  TINYINT, Word VARCHAR(1),SecondWord 
 VARCHAR(2),SecondFrequency TINYINT)

 INSERT INTO #Table1(Id, Word ,Frequency)
 SELECT 1,'A',1 UNION ALL
 SELECT 2,'B',5

 INSERT INTO #Table2(Id, Word ,SecondWord ,SecondFrequency)
 SELECT 1,'A','A1',1 UNION ALL           
 SELECT 2,'A','A2',5 UNION ALL
 SELECT 3,'A','A3',10 UNION ALL 
 SELECT 4,'A','A4',9 UNION ALL
 SELECT 5,'A','A5',20 UNION ALL
 SELECT 6,'B','B1',5 UNION ALL 
 SELECT 7,'B','B2',8 UNION ALL
 SELECT 8,'B','B3',50 UNION ALL
 SELECT 9,'B','B4',40 UNION ALL
 SELECT 10,'B','B5',68

 SELECT *
 FROM 
 (
    SELECT ROW_NUMBER() OVER(PARTITION BY #Table1.Word ORDER BY  
            SecondFrequency DESC ) RNo ,#Table1.Word ,#Table1.Frequency,
            SecondWord ,SecondFrequency
    FROM #Table1
    JOIN #Table2 ON #Table1.Word = #Table2.Word
 ) A 
  WHERE RNo BETWEEN 1 AND 3 

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