Android sqlite 数据库查询，插入，删除，更新demo<第1章>

//20140424

创建数据库帮助类DataBaseHelper，继承SQLiteOpenHelper, 

1.  编写构造函数，实现数据库创建；

public static final String TAG = "ListViewActivity";


private static int VERSION = 1;
private static final String TABLE_NAME = "user1";
private static final String SQL_CREATE = "CREATE TABLE user1(_id integer not null primary key autoincrement,"
+ "name text not null,"
+ "number text not null)";/*  表中主键id 要写成 _id  
*   数据库版本 >=1
*/
public DataBaseHelper(Context context, String name){

this(context,TABLE_NAME,null,VERSION); // context是Activity
}

public DataBaseHelper(Context context, String name, CursorFactory factory,
int version) {
super(context, name, factory, version);
// TODO Auto-generated constructor stub
}

 2. 复写onCreate()方法，此方法只会在数据库不存在的时候调用，也就是说，数据库存在的情况下则不会调用。

public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
Log.i(TAG, "onCreate ");
db.execSQL(SQL_CREATE);
}

 3.  insert

public void insertDataBase(SQLiteDatabase db,String name,String number)throws SQLiteException{

ContentValues values = new ContentValues();

Log.i(TAG,"insertDataBase : name = "+name+"number = "+number);
values.put("name", name);
values.put("number",number);

db.insert(TABLE_NAME, null, values);
}

 4.  updata

 5. delete

public void updataDataBase(SQLiteDatabase db,int id,ContentValues values){

String[] args = {String.valueOf(id)};   //  args不能写成 new String[]{"id"}  下同

db.update(TABLE_NAME, values,"_id=?",args);
}

 

public void deleteUserDataToDataBase(SQLiteDatabase db,int id){

Log.i(TAG, "id = "+id);
String[] args = {String.valueOf(id)};

db.delete(TABLE_NAME, "_id=?", args);
}

  6.  select

public Cursor getCursor(SQLiteDatabase db){

return db.query(TABLE_NAME, new String[]{"_id","name","number"}, null, null, null, null, null);
}

 7. version  updata，在此没有使用。

public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub

}//  不废话了，上代码：

package com.example.listviewdatabase;


 import android.content.ContentValues;
 import android.content.Context;
 import android.database.Cursor;
 import android.database.sqlite.SQLiteDatabase;
 import android.database.sqlite.SQLiteDatabase.CursorFactory;
 import android.database.sqlite.SQLiteException;
 import android.database.sqlite.SQLiteOpenHelper;
 import android.util.Log;


 public class DataBaseHelper extends SQLiteOpenHelper {

public static final String TAG = "ListViewActivity";


private static int VERSION = 1;
private static final String TABLE_NAME = "user1";
private static final String SQL_CREATE = "CREATE TABLE user1(_id integer not null primary key autoincrement,"
+ "name text not null,"
+ "number text not null)";

public DataBaseHelper(Context context, String name){

this(context,TABLE_NAME,null,VERSION);
}

public DataBaseHelper(Context context, String name, CursorFactory factory,
int version) {
super(context, name, factory, version);
// TODO Auto-generated constructor stub
}

@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
Log.i(TAG, "onCreate ");
db.execSQL(SQL_CREATE);
}

public void insertDataBase(SQLiteDatabase db,String name,String number)throws SQLiteException{

ContentValues values = new ContentValues();

Log.i(TAG,"insertDataBase : name = "+name+"number = "+number);
values.put("name", name);
values.put("number",number);

db.insert(TABLE_NAME, null, values);
}


public void updataDataBase(SQLiteDatabase db,int id,ContentValues values){

String[] args = {String.valueOf(id)};

db.update(TABLE_NAME, values,"_id=?",args);
}

public void deleteUserDataToDataBase(SQLiteDatabase db,int id){

Log.i(TAG, "id = "+id);
String[] args = {String.valueOf(id)};

db.delete(TABLE_NAME, "_id=?", args);
}

public Cursor getCursor(SQLiteDatabase db){

return db.query(TABLE_NAME, new String[]{"_id","name","number"}, null, null, null, null, null);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub

}
}

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