Android的SQLite的删除查询不工作 [英] android sqlite delete query not working

问题描述

以下SQLite的查询不会删除其ID的开头零。

The following sqlite query does not delete IDs which starts with zero.

Android的SQLite表结构

Android Sqlite Table structure

 String CREATE_TABLE_BUS = "CREATE TABLE " + TABLE_BUS + "("
                    + KEY_TID + " INTEGER PRIMARY KEY AUTOINCREMENT,"    
                    + KEY_BUS_NUM + " TEXT,"
                    + KEY_BUS_NAME + " TEXT,"
                    + KEY_FROM + " TEXT,"
                    + KEY_TO + " TEXT,"
                    + KEY_TYPE + " TEXT"
                    + ")";

            db.execSQL(CREATE_TABLE_BUS);

我一直BUS_NUM为文本，而不是为int的某种目的。

I kept BUS_NUM as text and not as int for some purpose.

这是功能我呼吁删除行。

And this is the function I call to delete a row..

        public void Delete_Bus(String bus_num) {
            SQLiteDatabase db = this.getWritableDatabase();

            db.delete(TABLE_BUS, KEY_BUS_NUM+"="+bus_num , null);
              Log.e("deleting bus num", bus_num);

            db.close(); // Closing database connection
        }

这code工作很细，当code不从零开始。

This code works very fine when the code does not start with zero..

它的工作原理为76555，而不是为09877.请告诉我错了我的code

It works for 76555 and not for 09877. Whats wrong with my code

推荐答案

本code生成的查询结尾是这样的：

The query generated by this code ends like this:

DELETE FROM BusTable WHERE BusNum = 012345

该数据库将跨preT这是一个数字，而不是字符串。

The database will interpret this as a number, not a string.

在SQL中，字符串必须用引号引起来：

In SQL, strings must be quoted:

DELETE FROM BusTable WHERE BusNum = '012345'

不过，你可以避免通过参数来格式化字符串：

However, you can avoid having to format the string by using a parameter:

db.delete(TABLE_BUS, KEY_BUS_NUM + " = ?", new String[] { bus_num });

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