sqlite語法備忘錄-文庫吧
2025-07-20 09:38 本頁面
【正文】 ::=CREATE [TEMP | TEMPORARY] TRIGGER triggername INSTEAD OFdatabaseevent ON [databasename .] viewnametriggeractiondatabaseevent::=DELETE | INSERT | UPDATE | UPDATE OF columnlisttriggeraction::=[ FOR EACH ROW | FOR EACH STATEMENT ] [ WHEN expression ] BEGIN triggerstep 。 [ triggerstep 。 ]*ENDtriggerstep::=updatestatement | insertstatement | deletestatement | selectstatement例子：CREATE TRIGGER update_customer_address UPDATE OF address ON customers BEGIN UPDATE orders SET address = WHERE customer_name = 。 END。說明：創(chuàng)建了一個名為update_customer_address的觸發(fā)器，當(dāng)用戶更新customers表中的address字段時，將觸發(fā)并更新orders表中的address字段為新的值。比如執(zhí)行如下一條語句：UPDATE customers SET address = 39。1 Main St.39。 WHERE name = 39。Jack Jones39。數(shù)據(jù)庫將自動執(zhí)行如下語句：UPDATE orders SET address = 39。1 Main St.39。 WHERE customer_name = 39。Jack Jones39。CREATE INDEX為給定表或視圖創(chuàng)建索引。語法：sqlstatement::=CREATE [UNIQUE] INDEX indexname ON [databasename .] tablename ( columnname [, columnname]* )[ ON CONFLICT conflictalgorithm ]columnname::=name [ COLLATE collationname] [ ASC | DESC ]例子：CREATE INDEXidx_ ON customers ()。說明：為customers表中的創(chuàng)建一個名為idx_的字段。結(jié)構(gòu)刪除DROP TABLE刪除表定義及該表的所有索引。語法：sqlmand::=DROP TABLE [databasename.] tablename例子：DROP TABLE c
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