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我试图弄清楚如何通过单击按钮来删除整个表格，所以可以说我有一个名为 Delete 的按钮，我想按下它并删除表格中的所有内容。
我试过了，但没有用我不知道在按钮上放什么

void deleteAll()
{
    SQLiteDatabase db= ourHelper.getWritableDatabase();
    db.delete(DATABASE_TABLE, null, null);
}

代码：

package f.s.l;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;

public class HotOrNot {
public static final String KEY_ROWID ="_id";
public static final String KEY_NAME ="persons_name";
public static final String KEY_HOTNESS ="persons_hotness";

private static final String DATABASE_NAME ="HotOrNotdb";
private static final String DATABASE_TABLE ="peopleTable";
private static final int DATABASE_VERSION =1;

private DbHelper ourHelper;
private final Context ourContext;
private SQLiteDatabase ourDatabase;

private static class DbHelper extends SQLiteOpenHelper{

public DbHelper(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
    // TODO Auto-generated constructor stub
}

@Override
public void onCreate(SQLiteDatabase db) {
    // TODO Auto-generated method stub
    db.execSQL("CREATE TABLE " + DATABASE_TABLE + " (" +
        KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
        KEY_NAME + " TEXT NOT NULL, " +
        KEY_HOTNESS + " TEXT NOT NULL);"
    );
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    // TODO Auto-generated method stub
    db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);
    onCreate(db);
}
}

public HotOrNot(Context c){
    ourContext =c;
}

public HotOrNot open() throws SQLException {
    ourHelper = new DbHelper(ourContext);
    ourDatabase = ourHelper.getWritableDatabase();
    return this;
}

public void close(){
    ourHelper.close();
}

public long createEntry(String name, String hotness) {
    // TODO Auto-generated method stub
    ContentValues cv = new ContentValues();
    cv.put(KEY_NAME, name);
    cv.put(KEY_HOTNESS, hotness);
    return ourDatabase.insert(DATABASE_TABLE, null, cv);
}

public String getData() {
    // TODO Auto-generated method stub
    String [] columns = new String[]{ KEY_ROWID, KEY_NAME, KEY_HOTNESS};
    Cursor c = ourDatabase.query(DATABASE_TABLE, columns, null, null, null, null, null);
    String result = "";

    int iRow = c.getColumnIndex(KEY_ROWID);
    int iName = c.getColumnIndex(KEY_NAME);
    int iHotness = c.getColumnIndex(KEY_HOTNESS);

    for(c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) {
        result = result + c.getString(iRow) + " "+ c.getString(iName) + " " + c.getString(iHotness) + "\n";
}

return result;
}

}
4

2 回答 2

3

你可以做

db.execSQL("DELETE * FROM " + DATABASE_TABLE);

这不会删除表，但会删除表中的所有行。

于 2012-04-29T00:30:47.167 回答
0

尝试使用 drop table 命令，我认为它必须是 drop table

于 2012-04-29T03:53:39.210 回答