从sqlite数据库中删除所有表 [英] Delete all tables from sqlite database

问题描述

我做了大量的研究，无法找到一个合适的方法来删除SQLite数据库中的所有表。最后，我做了一个代码，从数据库中获取所有表名，并且我试图逐个使用检索的表名删除表。它没有工作，以及。

I have done a lot of research and was unable to find a suitable method to delete all the tables in an SQLite database. Finally, I did a code to get all table names from the database and I tried to delete the tables using the retrieved table names one by one. It didn't work as well.

请向我建议一种从数据库中删除所有表格的方法。

Please suggest me a method to delete all tables from the database.

这是我使用的代码：

public void deleteall(){
    SQLiteDatabase db = this.getWritableDatabase();
    Cursor c = db.rawQuery("SELECT name FROM sqlite_master WHERE type='table'", null);
    do
    {
        db.delete(c.getString(0),null,null);
    }while (c.moveToNext());
}

函数 deleteall（）在按钮点击时调用谁的代码如下：

function deleteall() is called on button click whos code is given as below:

public void ButtonClick(View view)
{
    String Button_text;
    Button_text = ((Button) view).getText().toString();

    if(Button_text.equals("Delete Database"))
    {
        DatabaseHelper a = new DatabaseHelper(this);
        a.deleteall();
        Toast.makeText(getApplicationContext(), "Database Deleted Succesfully!", Toast.LENGTH_SHORT).show();
    }}

推荐答案

使用 DROP TABLE ：

// query to obtain the names of all tables in your database
Cursor c = db.rawQuery("SELECT name FROM sqlite_master WHERE type='table'", null);
List<String> tables = new ArrayList<>();

// iterate over the result set, adding every table name to a list
while (c.moveToNext()) {
    tables.add(c.getString(0));
}

// call DROP TABLE on every table name
for (String table : tables) {
    String dropQuery = "DROP TABLE IF EXISTS " + table;
    db.execSQL(dropQuery);
}

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