如何在查詢中添加變量名稱的雙引號？

Question

如何在字符串變量上添加任何想法？我的數據庫執行查詢，如果""是圍繞變量名稱，我該怎麼辦？我這樣做"+"+ School_name+"+"，但它不工作如何添加引用的變量名？

 Bundle bundle = this.getIntent().getExtras(); 
     School_name = bundle.getString("Serachvalue"); 



      db.selectQuery("SELECT * FROM uss_school sch LEFT JOIN uss_school_to_level sl ON 
    sch.school_id = sl.school_id LEFT JOIN uss_level l ON sl.level_id = l.level_id WHERE 
    l.title ="+ School_name+" ORDER BY sch.name ASC"); 

但數據的基礎上加上引號執行wuery用，

  SELECT * FROM uss_school sch LEFT JOIN uss_school_to_level sl ON sch.school_id = 
        sl.school_id LEFT JOIN uss_level l ON sl.level_id 
= l.level_id WHERE l.title = "Elementary" ORDER BY sch.name ASC 

Answer 1

嘗試以下方法，

db.selectQuery("SELECT * FROM uss_school sch LEFT JOIN uss_school_to_level sl ON 
    sch.school_id = sl.school_id LEFT JOIN uss_level l ON sl.level_id = l.level_id WHERE 
    l.title ='"+ School_name+"' ORDER BY sch.name ASC"); 

您只需只要您使用的查詢字段字符串變量添加'。