選擇子字符串以空格分隔的列中計數最高的子字符串

Question

如何選擇字中空格分隔的列中最常用的字？我使用SQLite作爲數據庫。

例如，

Column1 Column2 
1  Apple Orange Banana 
2  Strawberry Apple Pineapple 
3  Grape Mango 

所需的輸出：蘋果

Answer 1

字計數。假設你的表被稱爲yourTable。使用公用表表達式（with clause）將Column2拆分爲單獨的單詞。我借了一些知識，從user1461607以及與此想出了：。

WITH RECURSIVE split(word, str, hasspace) AS (
SELECT '', Column2, 1 from yourTable 
UNION ALL SELECT 
substr(str, 0, 
    case when instr(str, ' ') 
    then instr(str, ' ') 
    else length(str)+1 end), 
ltrim(substr(str, instr(str, ' ')), ' '), 
instr(str, ' ') 
FROM split 
WHERE hasspace 
) 
SELECT trim(word) FROM split WHERE word!='' GROUP BY trim(word) ORDER BY count(*) DESC LIMIT 1