SQLite数据库

一、新建数据库

1.新建数据库的类

 

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class SQLiteDataBase extends SQLiteOpenHelper {
	
	private static final String name = "android"; //数据库名称
    private static final int version = 1; //数据库版本
	
	public SQLiteDataBase(Context context) {
		super(context, name, null, version);
	}

	@Override
	public void onCreate(SQLiteDatabase db) {
		//使用事务操作SQLite数据库
		db.beginTransaction();
		try{
			db.execSQL("CREATE TABLE IF NOT EXISTS person (id integer primary key autoincrement, name varchar(20), age INTEGER)"); 
			db.execSQL("CREATE TABLE IF NOT EXISTS perchase (buyid integer primary key autoincrement, name varchar(20), good varchar(20), num INTEGER)"); 
			db.setTransactionSuccessful();
		}finally{
			db.endTransaction();
		}
		
	}

	@Override
	public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
		try{
			db.execSQL("DROP TABLE IF EXISTS person");
			db.execSQL("DROP TABLE IF EXISTS perchase");
		}finally{
			db.endTransaction();
		}
        onCreate(db);
	}

}

 2.新建数据库的代码:

 

SQLiteDataBase databaseHelper = new SQLiteDataBase(DatabaseOperation.this);
        SQLiteDatabase db = databaseHelper.getWritableDatabase();
        db.execSQL("insert into person(name, age) values(?,?)", new Object[]{"翠云 ", 4});
        db.close();  

 

二、查看数据

 

SQLiteDataBase databaseHelper = new SQLiteDataBase(AllDatabase.this);
        SQLiteDatabase db = databaseHelper.getWritableDatabase();
        Cursor cursor = db.rawQuery("select * from person", null);
        int num = cursor.getCount();
        while (cursor.moveToNext()) {
        	int personid = cursor.getInt(0); //获取第一列的值,第一列的索引从0开始
        	String name = cursor.getString(1);//获取第二列的值
        	int age = cursor.getInt(2);//获取第三列的值
        }
        cursor.close();
        db.close(); 

 三、删除数据

 

        SQLiteDataBase databaseHelper = new SQLiteDataBase(AllDatabase.this);
        SQLiteDatabase db = databaseHelper.getWritableDatabase();
        db.execSQL("delete from person where id = ?", new Object[]{id});
        //db.delete("person","id=?",new String[]{"'+id+'"});
        db.close(); 

 

四、插入数据

 

SQLiteDataBase databaseHelper = new SQLiteDataBase(InsertDatabase.this);
		        SQLiteDatabase db = databaseHelper.getWritableDatabase();
				db.execSQL("insert into person(name, age) values(?, ?)",new Object[]{ str_name , int_age});
				db.close();

五、查找数据

 

SQLiteDatabase db = (new SQLiteDataBase(SearchDatabase.this)).getReadableDatabase();
				Cursor cursor = null;
				cursor = db.rawQuery("select * from person where age = " + (Integer.parseInt(keyWord)),null);
				while (cursor.moveToNext()) {
					int personid = cursor.getInt(0); //获取第一列的值,第一列的索引从0开始
					String name = cursor.getString(1);//获取第二列的值
					int age = cursor.getInt(2);//获取第三列的值
				}
				cursor.close();
				db.close(); 

 

六、更新数据

 

		        SQLiteDataBase databaseHelper = new SQLiteDataBase(UpdateDatabase.this);
		        SQLiteDatabase db = databaseHelper.getWritableDatabase();
				db.execSQL("update person set name = ? , age = ? where id = ?",new Object[]{ str_name , int_age , id});
				db.close();