为什么我收到表名的列不存在错误

编程入门行业动态更新时间:2024-10-24 08:27:27

本文介绍了为什么我收到表名的列不存在错误的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！问题描述

大家好，我正在尝试检索我在之前的活动中插入到数据库中的一些数据.这是我检索数据的代码

Hi guys Im trying to retrieve some data I inserted into a database in a previous activity. This is my code to Retrieve the data

public class Display_data extends AppCompatActivity { ArrayList<String> Displist = new ArrayList<String>(); ListView no_name; String db_Name; TextView namer; TextView Starter; TextView Ender; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_display_data); Bundle bundle = getIntent().getExtras(); no_name = (ListView) findViewById(R.id.Disp_list); String message = bundle.getString("package"); String parameter; SQLiteDatabase db = openOrCreateDatabase(message, SQLiteDatabase.CREATE_IF_NECESSARY, null); SQLiteDatabase db1 = openOrCreateDatabase("Train_list.db", SQLiteDatabase.CREATE_IF_NECESSARY, null); Cursor header; namer=(TextView)findViewById(R.id.T1); try { header = db1.rawQuery("Select Train_name From Train_list Where Train_no="+message.substring(0,(message.length()-3)), null); header.moveToFirst(); String temp = header.getString((header.getColumnIndex("Train_name"))); Toast.makeText(Display_data.this, "blahhh:"+temp, Toast.LENGTH_LONG).show(); Log.d("Sucess!","temp:"+temp); Toast.makeText(Display_data.this, "Gotcha:"+temp , Toast.LENGTH_LONG).show(); namer.setText("Train Name: " + temp); }catch(Exception e) { Log.d("Final Error",e.toString()); Toast.makeText(Display_data.this, "Error", Toast.LENGTH_LONG).show(); } db_Name=message.substring(0,(message.length()-3)); try{ Cursor data_fetch = db.rawQuery("Select Stops From "+db_Name, null); while (data_fetch.moveToNext()) { String name = data_fetch.getString(data_fetch.getColumnIndex("Stops")); if(Displist.contains(name)) { } else { Displist.add(name); //Toast.makeText(Display_data.this, "Added :"+name, Toast.LENGTH_SHORT).show(); } } data_fetch.close(); }catch (Exception e) { Toast.makeText(Display_data.this, "Yeah"+e.toString(), Toast.LENGTH_LONG).show(); Log.d("Damn Why",e.toString()); } try { ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>( this, android.R.layout.simple_list_item_1,Displist); no_name.setAdapter(arrayAdapter); }catch (Exception e){ Log.d("Display data error ",e.toString()); Toast.makeText(Display_data.this, "Listview Error" , Toast.LENGTH_LONG).show(); } } }

我注意到该部分

try { header = db1.rawQuery("Select Train_name From Train_list Where Train_no="+message.substring(0,(message.length()-3)), null); header.moveToFirst(); String temp = header.getString((header.getColumnIndex("Train_name"))); Toast.makeText(Display_data.this, "blahhh:"+temp, Toast.LENGTH_LONG).show(); Log.d("Sucess!","temp:"+temp); Toast.makeText(Display_data.this, "Gotcha:"+temp , Toast.LENGTH_LONG).show(); namer.setText("Train Name: " + temp); }catch(Exception e) { Log.d("Final Error",e.toString()); Toast.makeText(Display_data.this, "Error", Toast.LENGTH_LONG).show(); }

返回错误

D/Final Error: android.database.sqlite.SQLiteException: no such column: aa1000 (code 1): , while compiling: Select Train_name From Train_list Where Train_no=aa1000

我真的不明白这个错误，因为'aa1000'被插入到数据库中.

I really don't understand this error as 'aa1000' was inserted into the database.

这是数据库'train_list'的定义

This is the definition for the database 'train_list'

SQLiteDatabase db = openOrCreateDatabase( "Train_list.db", SQLiteDatabase.CREATE_IF_NECESSARY , null); try { final String CREATE_TABLE_TRAIN_LIST = "CREATE TABLE IF NOT EXISTS Train_list (" + "Train_name VARCHAR," + "Train_no VARCHAR," + "Train_start VARCHAR," + "Train_end VARCHAR," + "Seats_Available VARCHAR);"; db.execSQL(CREATE_TABLE_TRAIN_LIST); Toast.makeText(admin_manipulation.this, "Table created", Toast.LENGTH_LONG).show(); String sql = "INSERT or replace INTO Train_list (Train_name, Train_no, Train_start, Train_end, Seats_Available) VALUES('"+str_Train_name + "',' " +str_Train_no + "', '" +str_Train_start+"','" +str_Train_end+"',' " +str_Train_seats +"');"; try { db.execSQL(sql); Toast.makeText(admin_manipulation.this, "train no:"+str_Train_no, Toast.LENGTH_SHORT).show(); }catch(Exception e) { Toast.makeText(admin_manipulation.this, "Sorry Not Inserted Sucessfully", Toast.LENGTH_SHORT).show(); Log.d("Error experienced",e.toString()); }

我检查了 Android Monitor 页面，没有发现提示aa1000"尚未插入数据库的错误.

I Checked the Android Monitor page and i did not find an error to suggest that "aa1000" had not been inserted into the database.

请注意，当只插入Train_name 和Train_no 时，其余都为空.

Please Do note that When inserting only Train_name and Train_no Were filled in the rest were left as null.

任何帮助将不胜感激！

推荐答案

将 aa1000 放入单引号 ('aa1000'):

Put aa1000 into single quotes ('aa1000'):

您的 SQL 查询应如下所示:

Your SQL query should look like:

Select Train_name From Train_list Where Train_no='aa1000'

因此在 db.rawQuery 中修改您的选择字符串: