如何創建和使用索引？

Question

我有SQLite數據庫表。雖然搜索它非常緩慢。需要20-30秒才能找到合適的單詞。原因是我正在使用（我必須）在我的查詢中加入2-3個WHERE子句。

query = "SELECT" + " e.id AS _id," + " ke.id AS ke_id," 
       + " ke.fk as ke_fk," + " ke.value as ke_value," 
       + " re.id AS ke_id," + " re.fk as re_fk," 
       + " re.value as re_value," + " s.id AS s_id," 
       + " s.fk as s_fk," + " g.id AS g_id," + " g.fk as g_fk," 
       + " g.lang," + " g.value as g_value" + " FROM entry e" 
       + "  INNER JOIN k_ele ke ON e.id = ke.fk" 
       + "  INNER JOIN r_ele re ON e.id = re.fk" 
       + "  INNER JOIN sense s ON e.id = s.fk" 
       + "  INNER JOIN gloss g ON s.id = g.fk" 
       + " WHERE g.lang IS NULL AND g.value like '" 
       + lookingFor + "%' GROUP BY g.value LIMIT 5"; 

這是表之間的關係：

我已閱讀有關索引（伯，唯一的）。我知道索引時的排序值。我的問題是如何創建（我不是在談論爲id創建PRIMARY UNIQUE INDEX，我說的是不在id列中進行搜索），並使用該索引來加速搜索查詢？以編程方式或在應用程序（SQLite專家專業）？如果我創建索引每次搜索時創建索引？

請給出您的意見或建議。謝謝。

Answer 1

LIKE在任何情況下都非常緩慢，並且不使用索引（如果我錯了，請糾正我）。如果您的目標是全文搜索，請查看SQLite的FTS3功能。那裏有很多樣品。例如：FTS3 blog