我正在创建一个监控出勤率的Android应用程序，但是当我尝试使用sqlite数据库中的用户详细信息登录时，我发现错误，表示列不存在。
DBHelper.class
package uk.ac.qub.qubattend;
import java.util.ArrayList;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
public class DBHelper extends SQLiteOpenHelper {
// Database Version
private static final int DATABASE_VERSION = 6;
// Database Name
private static final String DATABASE_NAME = "QUBAttendanceDB";
// tasks table name
private static final String TABLE_StudentInfo = "studentinfo";
// Table Columns names
// id column
private static final String KEY_ID = "StudentId";
// question column
private static final String KEY_PASS = "password";
// answer column
private static final String KEY_WEEK1 = "Week1";
private static final String KEY_WEEK2 = "Week2";
private static final String KEY_WEEK3 = "Week3";
private static final String KEY_WEEK4 = "Week4";
private static final String KEY_WEEK5 = "Week5";
private static final String KEY_WEEK6 = "Week6";
private static final String KEY_WEEK7 = "Week7";
private static final String KEY_WEEK8 = "Week8";
private static final String KEY_WEEK9 = "Week9";
private static final String KEY_WEEK10 = "Week10";
private static final String KEY_WEEK11 = "Week11";
private static final String KEY_WEEK12 = "Week12";
// Database constant
private SQLiteDatabase dbase;
/**
* Method to check the db name and version
*
* @param context
*/
public DBHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
dbase = db;
// Create Table method
String sql = "CREATE TABLE IF NOT EXISTS " + TABLE_StudentInfo + " ( "
+ KEY_ID + " TEXT," + KEY_PASS + " TEXT, " + KEY_WEEK1
+ "TEXT, " + KEY_WEEK2 + "TEXT, " + KEY_WEEK3 + "TEXT, "
+ KEY_WEEK4 + "TEXT, " + KEY_WEEK5 + "TEXT, " + KEY_WEEK6
+ "TEXT, " + KEY_WEEK7 + "TEXT, " + KEY_WEEK8 + "TEXT, "
+ KEY_WEEK9 + "TEXT, " + KEY_WEEK10 + "TEXT, " + KEY_WEEK11
+ "TEXT, " + KEY_WEEK12 + "TEXT" + ")";
db.execSQL(sql);
// implementing add questions method
addAttendance();
}
/**
* Add Questions Method using Question Object with question, 4 options and
* correct answer
*/
private void addAttendance() {
Student s1 = new Student("40023798", "letmeinhere", "90", "80", "0",
"0", "0", "0", "0", "0", "0", "0", "0", "0");
this.addStudent(s1);
}
// Checking that existing database table called TABLE_QUEST is dropped
@Override
public void onUpgrade(SQLiteDatabase db, int oldV, int newV) {
// Drop older table if existed
db.execSQL("DROP TABLE IF EXISTS " + TABLE_StudentInfo);
// Create tables again
onCreate(db);
}
/**
* method for adding a new question into the database
*
* @param quest
*/
public void addStudent(Student student) {
ContentValues values = new ContentValues();
values.put(KEY_ID, student.getStudentId());
values.put(KEY_PASS, student.getPassword());
values.put(KEY_WEEK1, student.getWeek1());
values.put(KEY_WEEK2, student.getWeek2());
values.put(KEY_WEEK3, student.getWeek3());
values.put(KEY_WEEK4, student.getWeek4());
values.put(KEY_WEEK5, student.getWeek5());
values.put(KEY_WEEK6, student.getWeek6());
values.put(KEY_WEEK7, student.getWeek7());
values.put(KEY_WEEK8, student.getWeek8());
values.put(KEY_WEEK9, student.getWeek9());
values.put(KEY_WEEK10, student.getWeek10());
values.put(KEY_WEEK11, student.getWeek11());
values.put(KEY_WEEK12, student.getWeek12());
// Inserting Row with question
dbase.insert(TABLE_StudentInfo, null, values);
}
/**
* Method to move questions in database to an ArrayList
*
* @return
*/
public ArrayList<Student> getAllStudents() {
ArrayList<Student> studentList = new ArrayList<Student>();
// Select All Query
String selectQuery = "SELECT * FROM " + TABLE_StudentInfo;
dbase = this.getReadableDatabase();
Cursor cursor = dbase.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
Student student = new Student();
student.setStudentId(cursor.getString(0));
student.setPassword(cursor.getString(1));
student.setWeek1(cursor.getString(2));
student.setWeek2(cursor.getString(3));
student.setWeek3(cursor.getString(4));
student.setWeek4(cursor.getString(5));
student.setWeek5(cursor.getString(6));
student.setWeek6(cursor.getString(7));
student.setWeek7(cursor.getString(8));
student.setWeek8(cursor.getString(9));
student.setWeek9(cursor.getString(10));
student.setWeek10(cursor.getString(11));
student.setWeek11(cursor.getString(12));
student.setWeek12(cursor.getString(13));
studentList.add(student);
} while (cursor.moveToNext());
}
// return question list
return studentList;
}
/**
* Method to Check Database number of rows
*
* @return
*/
public int rowcount() {
int row = 0;
// select all query
String selectQuery = "SELECT * FROM " + TABLE_StudentInfo;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
row = cursor.getCount();
return row;
}
}
下面是显示错误的日志，但我不知道为什么会抛出错误：
01-17 16:26:51.616: E/SQLiteLog(1667): (1) table studentinfo has no column named Week8
01-17 16:26:51.656: E/SQLiteDatabase(1667): Error inserting StudentId=40023798 Week8=0 Week9=0 Week4=0 Week5=0 password=letmeinhere Week6=0 Week7=0 Week3=0 Week2=80 Week12=0 Week1=90 Week11=0 Week10=0
01-17 16:26:51.656: E/SQLiteDatabase(1667): android.database.sqlite.SQLiteException: table studentinfo has no column named Week8 (code 1): , while compiling: INSERT INTO studentinfo(StudentId,Week8,Week9,Week4,Week5,password,Week6,Week7,Week3,Week2,Week12,Week1,Week11,Week10) VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?,?)
01-17 16:26:51.656: E/SQLiteDatabase(1667): at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
01-17 16:26:51.656: E/SQLiteDatabase(1667): at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:889)
01-17 16:26:51.656: E/SQLiteDatabase(1667): at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:500)
01-17 16:26:51.656: E/SQLiteDatabase(1667): at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
01-17 16:26:51.656: E/SQLiteDatabase(1667): at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
01-17 16:26:51.656: E/SQLiteDatabase(1667): at android.database.sqlite.SQLiteStatement.<init>(SQLiteStatement.java:31)
01-17 16:26:51.656: E/SQLiteDatabase(1667): at android.database.sqlite.SQLiteDatabase.insertWithOnConflict(SQLiteDatabase.java:1467)
01-17 16:26:51.656: E/SQLiteDatabase(1667): at android.database.sqlite.SQLiteDatabase.insert(SQLiteDatabase.java:1339)
01-17 16:26:51.656: E/SQLiteDatabase(1667): at uk.ac.qub.qubattend.DBHelper.addStudent(DBHelper.java:109)
01-17 16:26:51.656: E/SQLiteDatabase(1667): at uk.ac.qub.qubattend.DBHelper.addAttendance(DBHelper.java:73)
01-17 16:26:51.656: E/SQLiteDatabase(1667): at uk.ac.qub.qubattend.DBHelper.onCreate(DBHelper.java:62)
01-17 16:26:51.656: E/SQLiteDatabase(1667): at uk.ac.qub.qubattend.DBHelper.onUpgrade(DBHelper.java:83)
01-17 16:26:51.656: E/SQLiteDatabase(1667): at android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:257)
01-17 16:26:51.656: E/SQLiteDatabase(1667): at android.database.sqlite.SQLiteOpenHelper.getReadableDatabase(SQLiteOpenHelper.java:188)
如果有人知道为什么它没有拿到第8列，我会非常感激！
答案 0 :(得分：0)
所有KEY_WEEK...值都附加"TEXT, "，而不是" TEXT, "，因此您的列和数据类型名称应该一起运行。
使用StringBuilder（更快）或String.format()（更易于阅读），而不是使用字符串连接，您可能会得到更好的服务。