Android Stdio使用SQLite创建数据库示例

public class DBAdapter {

   private static final String DB_NAME = "people.db";
   private static final String DB_TABLE = "peopleinfo";
   private static final int DB_VERSION = 1;
    
   public static final String KEY_ID = "_id";
   public static final String KEY_NAME = "name";
   public static final String KEY_AGE = "age";
   public static final String KEY_HEIGHT = "height";
   
   private SQLiteDatabase db;
   private final Context context;
   private DBOpenHelper dbOpenHelper;
   
   public DBAdapter(Context _context) {
       context = _context;
     }

     /** Close the database */
     public void close() {
        if (db != null){
           db.close();
           db = null;
        }
      }

     /** Open the database */
     public void open() throws SQLiteException {  
        dbOpenHelper = new DBOpenHelper(context, DB_NAME, null, DB_VERSION);
        try {
           db = dbOpenHelper.getWritableDatabase();
        }
        catch (SQLiteException ex) {
           db = dbOpenHelper.getReadableDatabase();
        }      
      }
     
   
     public long insert(People people) {
       ContentValues newValues = new ContentValues();
     
       newValues.put(KEY_NAME, people.Name);
       newValues.put(KEY_AGE, people.Age);
       newValues.put(KEY_HEIGHT, people.Height);
       
       return db.insert(DB_TABLE, null, newValues);
     }


     public People[] queryAllData() {  
        Cursor results =  db.query(DB_TABLE, new String[] { KEY_ID, KEY_NAME, KEY_AGE, KEY_HEIGHT}, 
              null, null, null, null, null);
        return ConvertToPeople(results);   
     }
     
     public People[] queryOneData(long id) {  
        Cursor results =  db.query(DB_TABLE, new String[] { KEY_ID, KEY_NAME, KEY_AGE, KEY_HEIGHT}, 
              KEY_ID + "=" + id, null, null, null, null);
        return ConvertToPeople(results);   
     }
     
     private People[] ConvertToPeople(Cursor cursor){
        int resultCounts = cursor.getCount();
        if (resultCounts == 0 || !cursor.moveToFirst()){
           return null;
        }
        People[] peoples = new People[resultCounts];
        for (int i = 0 ; i<resultCounts; i++){
           peoples[i] = new People();
           peoples[i].ID = cursor.getInt(0);
           peoples[i].Name = cursor.getString(cursor.getColumnIndex(KEY_NAME));
           peoples[i].Age = cursor.getInt(cursor.getColumnIndex(KEY_AGE));
           peoples[i].Height = cursor.getFloat(cursor.getColumnIndex(KEY_HEIGHT));
           
           cursor.moveToNext();
        }      
        return peoples; 
     }
     
     public long deleteAllData() {
        return db.delete(DB_TABLE, null, null);
     }

     public long deleteOneData(long id) {
        return db.delete(DB_TABLE,  KEY_ID + "=" + id, null);
     }

     public long updateOneData(long id , People people){
        ContentValues updateValues = new ContentValues();      
        updateValues.put(KEY_NAME, people.Name);
        updateValues.put(KEY_AGE, people.Age);
        updateValues.put(KEY_HEIGHT, people.Height);
        
        return db.update(DB_TABLE, updateValues,  KEY_ID + "=" + id, null);
     }
     
      /** 静态Helper类，用于建立、更新和打开数据库*/
     private static class DBOpenHelper extends SQLiteOpenHelper {

        public DBOpenHelper(Context context, String name, CursorFactory factory, int version) {
          super(context, name, factory, version);
        }

        private static final String DB_CREATE = "create table " + 
          DB_TABLE + " (" + KEY_ID + " integer primary key autoincrement, " +
          KEY_NAME+ " text not null, " + KEY_AGE+ " integer," + KEY_HEIGHT + " float);";

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

        @Override
        public void onUpgrade(SQLiteDatabase _db, int _oldVersion, int _newVersion) {           
          _db.execSQL("DROP TABLE IF EXISTS " + DB_TABLE);
          onCreate(_db);
        }
      }
   }