Delete data from SQLite-Database

Hi 开发者_运维技巧im strugeling with SQLite in android.

Im trying to delete old posts from the db by doing this

this.db.delete(
  EVENT_TABLE_NAME,
  "date < ?", 
  new String[] {String.valueOf(limit.getTime())}
);

Where limit is the current date taken from the Calendar instances and deducted 216000000 milliseconds.

But this seems to remove all posts.

---

try this

this.db.delete(
  EVENT_TABLE_NAME,
  "date < "+limit.getTime(),null);

---

My guess would be:

context.deleteDatabase(DATABASE_NAME);

---

You can try something like this:

public static String getDateStringFromDate(Date date, String pattern,
                                           String timezone) {
    // Set locale to US to prevent date issues
    if (!Locale.getDefault().equals(Locale.US)) {
        Locale.setDefault(Locale.US);
    }
    SimpleDateFormat df = new SimpleDateFormat(pattern);
    if (timezone != null) {
        df.setTimeZone(TimeZone.getTimeZone(timezone));
    }
    if (date == null) {
        return null;
    }
    try {
        return df.format(date);
    } catch (Exception e) {
        e.printStackTrace();
        return null;
    }
}

This function will create a string with your custom date format and you ca create a functional query :) And after that you can use the delete function like this:

this.db.delete(
    EVENT_TABLE_NAME,
    "date < ?", 
    new String[] {getDateStringFromDate(date,pattern,timezone)}

);

---

This is working for me :

    public static boolean deleteData(String tableName,String where, String[] value){
    sqliteDb = instance.getWritableDatabase();
    sqliteDb.delete(tableName, where, value);
    return true;
    }