函数增删改查数据库

来源：互联网发布：颈椎牵引器淘宝编辑：程序博客网时间：2024/06/03 17:54
package com.bwei.acid.dao;import android.content.ContentValues;import android.content.Context;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import com.bwei.acid.db.MySqliteOpenHelper;public class StudentDao {private MySqliteOpenHelper helper;public StudentDao(Context context) {helper = new MySqliteOpenHelper(context);}// 增加public void add(String name, int age) {SQLiteDatabase db = helper.getWritableDatabase();ContentValues values = new ContentValues();values.put("name", name);values.put("age", age);/** * 第一个参数表明 * 第二个参数是列 */db.insert("student", null, values );db.close();}// 删除public void delete(String name) {SQLiteDatabase db = helper.getWritableDatabase();db.delete("student", "name=?", new String[]{name});db.close();}// 修改public void update(String name) {SQLiteDatabase db = helper.getWritableDatabase();ContentValues values = new ContentValues();values.put("name", name);values.put("age", 888);db.update("student", values , "name=?", new String[]{name});db.close();}// 查询public void query() {SQLiteDatabase db = helper.getWritableDatabase();/** * Table 表名 Columens 要查询的列Selection 查询条件selectionArgs 查询条件占位符对应的内容groupBy 分组判断条件Having 是否含有的判断条件orderBy  排序判断条件Limit  分页查询判断条件 */Cursor cursor = db.query("student", null, null,null, null, null, null, null);while(cursor.moveToNext()){String name = cursor.getString(cursor.getColumnIndex("name"));int age = cursor.getInt(cursor.getColumnIndex("age"));System.out.println("name="+name+",age="+age);}}}
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