android下数据库的增删改查

在android应用程序中使用db.execSQL(“sql”,bindArgs)操作增删改查语句；
1、创建表结构
public void create(View v){

        db.execSQL("create table person (id integer primary key autoincrement,name varchar(20))", new Object[]{});        Toast.makeText(this, "创建表结构成功", 0).show();    }2、插入    public void insert(View v){            db.execSQL("insert into person (name)values(?)", new String[]{"lisi"});            Toast.makeText(this, "插入数据成功", 0).show();        }3、查询：db.rawQuery，cursor类似于一个指针，当cursor指向一条记录时，就把当前记录的数据封装到cursor中，直接从cursor取数据    public void query(View v){      Cursor cursor = db.rawQuery("select * from person",null);      //移动游标，返回值为true表示没有移动到数据集的最后（空），如果为false已经数据集的最后（没有数据了）      while(cursor.moveToNext()){         int id = cursor.getInt(0);         String name = cursor.getString(1);         System.out.println("id="+id+"; name="+name);      }      Toast.makeText(this, "查询数据成功", 0).show();    }4、更新  public void update(View v){        db.execSQL("update person set name='wangwu' where id=?", new Object[]{1});        Toast.makeText(this, "更新数据成功", 0).show();    }4、删除  public void delete(View v){        db.execSQL("delete from person where id=?", new Object[]{1});        Toast.makeText(this, "删除数据成功", 0).show();    }

数据库的另外一种增删改查方法:

使用google提供的另外一种方式操作数据库表：

1、插入数据public void insert(View v){//db.execSQL("insert into person (name)values(?)", new String[]{"lisi"});  ContentValues values = new ContentValues();  Random r = new Random();  values.put("name", "zhangsan"+r.nextInt(100));   long rowId =  db.insert("person", null, values);  System.out.println("rowId="+rowId);    Toast.makeText(this, "插入数据成功", 0).show();}

2、查询数据
public void query(View v){
/**
* table 表名
* columns 查询的列
* selection 查询条件”id=1”
* selectionArgs 查询条件的值
* String groupBy
* String having
* String orderBy
*
*/
Cursor cursor = db.query(“person”, new String[]{“id”,”name” }, null, null, null, null, null);

  while(cursor.moveToNext()){     int id = cursor.getInt(0);     String name = cursor.getString(1);     System.out.println("id="+id+"; name="+name);  }  Toast.makeText(this, "查询数据成功", 0).show();}

public void update(View v){

//      db.execSQL("update person set name='wangwu' where id=?", new Object[]{1});//用来封装要修改的列名和值  ContentValues values = new ContentValues();  values.put("name", "wangwu");  db.update("person", values, "id=?", new String[]{"1"});  Toast.makeText(this, "更新数据成功", 0).show();}

public void delete(View v){

// db.execSQL(“delete from person where id=?”, new Object[]{1});
db.delete(“person”, “id=?”, new String[]{“2”});
Toast.makeText(this, “删除数据成功”, 0).show();

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