如何在查询中添加变量名称的双引号？

Question

如何在字符串变量上添加任何想法？我的数据库执行查询，如果""是围绕变量名称，我该怎么办？我这样做"+"+ School_name+"+"，但它不工作如何添加引用的变量名？

 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"); 

但数据的基础上加上引号执行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

尝试以下方法，

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询字段字符串变量添加'。