Question

我尝试在单击按钮时保存当前日期值....我使用DBAdapter将参数保存到sqlite，当用于2个字段（如DBAdapter的示例）时它很好但是当我为6个字段编辑DBAdapter时这不起作用那是我的问题？

DBAdapter.java

import java.io.StringReader;
import java.util.ArrayList;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.xml.sax.InputSource;
import org.xml.sax.XMLReader;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

public class DBAdapter {

private static final String TAG = "DBAdapter"; //used for logging database version changes

// Field Names:
public static final String KEY_ROWID = "_id";
public static final String KEY_YEAR = "year";
public static final String KEY_MONTH = "month";
public static final String KEY_DAY = "day";
public static final String KEY_HOUR = "hour";
public static final String KEY_MINUTE = "minute";
public static final String KEY_SECOND = "second";


public static final String[] ALL_KEYS = new String[] { KEY_ROWID, KEY_YEAR, KEY_MONTH, KEY_DAY, KEY_HOUR, KEY_MINUTE, KEY_SECOND};

// Column Numbers for each Field Name:
public static final int COL_ROWID = 0;
public static final int COL_TASK = 1;
public static final int COL_DATE = 2;

// DataBase info:
public static final String DATABASE_NAME = "dbToDo12";
public static final String DATABASE_TABLE = "mainToDo12";
public static final int DATABASE_VERSION = 2; // The version number must be incremented each time a change to DB structure occurs.

//SQL statement to create database
private static final String DATABASE_CREATE_SQL =
        "CREATE TABLE " + DATABASE_TABLE
                + " (" + KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, "
                + KEY_YEAR + " TEXT NOT NULL, "
                + KEY_MONTH + " TEXT"
                + KEY_DAY + " TEXT"
                + KEY_HOUR + " TEXT"
                + KEY_MINUTE + " TEXT"
                + KEY_SECOND + " TEXT"
                + ");";

private final Context context;
private DatabaseHelper myDBHelper;
private SQLiteDatabase db;


public DBAdapter(Context ctx) {
    this.context = ctx;
    myDBHelper = new DatabaseHelper(context);
}

// Open the database connection.
public DBAdapter open() {
    db = myDBHelper.getWritableDatabase();
    return this;
}

// Close the database connection.
public void close() {
    myDBHelper.close();
}

// Add a new set of values to be inserted into the database.
public long insertRow(String year, String month,String day, String hour,String minute,String second) {
    ContentValues initialValues = new ContentValues();
    initialValues.put(KEY_YEAR, year);
    initialValues.put(KEY_MONTH, month);
    initialValues.put(KEY_DAY, day);
    initialValues.put(KEY_HOUR, hour);
    initialValues.put(KEY_MINUTE, minute);
    initialValues.put(KEY_SECOND, second);

    // Insert the data into the database.
    return db.insert(DATABASE_TABLE, null, initialValues);
}

// Delete a row from the database, by rowId (primary key)
public boolean deleteRow(long rowId) {
    String where = KEY_ROWID + "=" + rowId;
    return db.delete(DATABASE_TABLE, where, null) != 0;
}

public void deleteAll() {
    Cursor c = getAllRows();
    long rowId = c.getColumnIndexOrThrow(KEY_ROWID);
    if (c.moveToFirst()) {
        do {
            deleteRow(c.getLong((int) rowId));
        } while (c.moveToNext());
    }
    c.close();
}

// Return all data in the database.
public Cursor getAllRows() {
    String where = null;
    Cursor c =  db.query(true, DATABASE_TABLE, ALL_KEYS, where, null, null, null, null, null);
    if (c != null) {
        c.moveToFirst();
    }
    return c;
}

// Get a specific row (by rowId)
public Cursor getRow(long rowId) {
    String where = KEY_ROWID + "=" + rowId;
    Cursor c =  db.query(true, DATABASE_TABLE, ALL_KEYS,
            where, null, null, null, null, null);
    if (c != null) {
        c.moveToFirst();
    }
    return c;
}

// Change an existing row to be equal to new data.
public boolean updateRow(long rowId, String year, String month,long day, String hour, String minute,long second) {
    String where = KEY_ROWID + "=" + rowId;
    ContentValues newValues = new ContentValues();
    newValues.put(KEY_YEAR, year);
    newValues.put(KEY_MONTH, month);
    newValues.put(KEY_DAY, day);
    newValues.put(KEY_HOUR, hour);
    newValues.put(KEY_YEAR, year);
    newValues.put(KEY_MINUTE, minute);
    newValues.put(KEY_SECOND, second);

    // Insert it into the database.
    return db.update(DATABASE_TABLE, newValues, where, null) != 0;
}


private static class DatabaseHelper extends SQLiteOpenHelper
{
    DatabaseHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase _db) {
        _db.execSQL(DATABASE_CREATE_SQL);
    }

    @Override
    public void onUpgrade(SQLiteDatabase _db, int oldVersion, int newVersion) {
        Log.w(TAG, "Upgrading application's database from version " + oldVersion
                + " to " + newVersion + ", which will destroy all old data!");

        // Destroy old database:
        _db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);

        // Recreate new database:
        onCreate(_db);
    }
}

}

MainActivity.java

import android.content.Context;
import android.database.Cursor;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Button;
import android.widget.Toast;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.view.View;
import java.util.Calendar;

public class MainActivity extends AppCompatActivity {
   Button plus;


int second,minute,houre,day,mounth,year;


DBAdapter mDb = new DBAdapter(this);

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    //setContentView(R.layout.activity_main);

    ViewGroup.LayoutParams superparams =
            new LinearLayout.LayoutParams(
                    ViewGroup.LayoutParams.WRAP_CONTENT,
                    ViewGroup.LayoutParams.MATCH_PARENT);
    LinearLayout table = new LinearLayout(this);
    plus = new Button(this);
    plus.setText("+");
    table.addView(plus);
    setContentView(table);

    plus.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            Calendar c = Calendar.getInstance();
            second = c.get(Calendar.SECOND);
            minute = c.get(Calendar.MINUTE);
            houre = c.get(Calendar.HOUR);
            day = c.get(Calendar.DAY_OF_MONTH);
            mounth = c.get(Calendar.MONTH);
            year = c.get(Calendar.YEAR);
            mDb.open();
            mDb.insertRow(Integer.toString(year), Integer.toString   (mounth),Integer.toString(day), Integer.toString(houre),Integer.toString(minute), Integer.toString(second));
            mDb.close();
            mDb.open();
            Cursor g=mDb.getRow(2);
            DisplayContact(g);
            mDb.close();
        }
    });
}
   public void DisplayContact(Cursor c)
{
    Toast.makeText(this,"id: "+c.getString(0)+"\n"+
                    "year: "+c.getString(1)+"\n"+
                    "month: "+c.getString(2),
            Toast.LENGTH_LONG).show();
}

}

Answer 1

您的列规范之间缺少逗号,：

+ KEY_MONTH + " TEXT"
+ KEY_DAY + " TEXT"
+ KEY_HOUR + " TEXT"
+ KEY_MINUTE + " TEXT"

添加缺少的逗号后，请先卸载应用程序或增加架构版本以重新创建表格。

向DBAdapter类添加更多字段

1 个答案: