Android studio中SQLite 数据库及表的创建与更新中用到的主要编程语句

以下是在Android Studio中使用SQLite数据库及表的创建和更新中主要用到的编程语句：

1. 创建数据库：

SQLiteDatabase db = openOrCreateDatabase("myDB", Context.MODE_PRIVATE, null);

2. 创建表：

String createTable = "CREATE TABLE myTable (id INTEGER PRIMARY KEY, name TEXT, age INTEGER)";
db.execSQL(createTable);

3. 插入数据：

String insertData = "INSERT INTO myTable (name, age) VALUES ('John', 25)";
db.execSQL(insertData);

4. 查询数据：

String queryData = "SELECT * FROM myTable WHERE age > 20";
Cursor cursor = db.rawQuery(queryData, null);
if (cursor.moveToFirst()) {
    do {
        String name = cursor.getString(cursor.getColumnIndex("name"));
        int age = cursor.getInt(cursor.getColumnIndex("age"));
    } while (cursor.moveToNext());
}

5. 更新数据：

String updateData = "UPDATE myTable SET age = 26 WHERE name = 'John'";
db.execSQL(updateData);

6. 删除数据：

String deleteData = "DELETE FROM myTable WHERE age < 20";
db.execSQL(deleteData);

7. 删除表：

String dropTable = "DROP TABLE IF EXISTS myTable";
db.execSQL(dropTable);