SQlite觸發器執行問題

Question

我是Android新手& SQlite。我試圖在Android中的SQLite數據庫上創建以下觸發器。

final String CREATE_TRIGGER_STATES = 
      "CREATE TRIGGER fk_insert_state BEFORE " 
      + "INSERT on tbl_states" 
      + "FOR EACH ROW " 
      + "BEGIN " 
      + "SELECT RAISE(ROLLBACK, 'insert on table " 
      + "\"tbl_states\" violates foreign key constraint " 
      + "\"fk_insert_state\"') WHERE (SELECT id FROM " 
      + "tbl_countries WHERE id = NEW.country_id) IS NULL; " 
      + "END;"; 
     db.execSQL(CREATE_TRIGGER_STATES); 

錯誤日誌：

android.database.sqlite.SQLiteException: near "EACH": syntax error: CREATE TRIGGER fk_insert_state BEFORE INSERT on tbl_statesFOR EACH ROW BEGIN SELECT RAISE(ROLLBACK, 'insert on table "tbl_states" violates foreign key constraint "fk_insert_state"') WHERE (SELECT id FROM tbl_countries WHERE id = NEW.country_id) IS NULL; END; 

是否存在與語法有問題？

Answer 1

我猜，錯誤信息的相關部分就在這裏：

... on tbl_statesFOR EACH ROW ... 
//--------------^^ 

你tbl_states後缺少空間：

final String CREATE_TRIGGER_STATES = 
      "CREATE TRIGGER fk_insert_state BEFORE " 
      + "INSERT on tbl_states " // Missing space added 
      //... Continue on as before. 

Answer 2

你忘了空間：

+ "INSERT on tbl_states " // Space missing here 
+ "FOR EACH ROW "