SQLite增删改查

package com.scme.db;

import java.util.ArrayList;
import java.util.List;

import com.scme.bean.Students;
import com.scme.bean.Tongxunlu;

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

public class DBHelper extends SQLiteOpenHelper {

    // 定义数据库名称
    private static final String DBNAME = "txl.db";
    // 定义数据库版本
    private static final int VERSION = 1;

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

    /**
     * 创建数据库表
     */
    @Override
    public void onCreate(SQLiteDatabase db) {
        String sql1 = "create table user_info (_id integer primary key autoincrement,stuName text,stuPwd text,stuSex text,stuAge integer)";
        String sql2 = "create table phone_info (_id integer primary key autoincrement,txlName text,txlPhone text,txlEmail text,txlAddr text)";
        db.execSQL(sql1);
        db.execSQL(sql2);
    }

    @Override
    public void onUpgrade(SQLiteDatabase arg0, int arg1, int arg2) {

    }

    /**
     * 注册
     */
    public void addStu(Students stu) {
        String sql = "insert into user_info(stuName,stuPwd,stuSex,stuAge) values (?,?,?,?)";
        SQLiteDatabase db = getWritableDatabase();
        db.execSQL(
                sql,
                new Object[] { stu.getStuName(), stu.getStuPwd(),
                        stu.getStuSex(), stu.getStuAge() });
        db.close();
    }

    /**
     * 登录
     *
     * @param name
     * @param pwd
     * @return
     */
    public boolean login(String name, String pwd) {
        String sql = "select * from user_info where stuName = " + name
                + " and stuPwd =" + pwd;
        SQLiteDatabase db = getReadableDatabase();
        Cursor c = db.rawQuery(sql, null);
        while (c.moveToNext()) {
            if (c.getString(1) != null) {
                return true;
            }
        }
        c.close();
        db.close();
        return false;
    }

    /**
     * 添加联系人
     *
     * @param txl
     */
    public void addTxl(Tongxunlu txl) {
        String sql = "insert into phone_info(txlName,txlPhone,txlEmail,txlAddr) values (?,?,?,?)";
        SQLiteDatabase db = getWritableDatabase();
        db.execSQL(
                sql,
                new Object[] { txl.getTxlName(), txl.getTxlPhone(),
                        txl.getTxlEmail(), txl.getTxlAddr() });
        db.close();
    }

    /**
     * 删除联系人
     *
     * @param id
     */
    public void delTxl(int id) {
        String sql = "delete from phone_info where _id = " + id;
        SQLiteDatabase db = getWritableDatabase();
        db.execSQL(sql);
        db.close();
    }

    /**
     * 修改联系人
     *
     * @param txl
     */
    public void updateTxl(Tongxunlu txl) {
        String sql = "update phone_info set txlName=?,txlPhone=?,txlEmail=?,txlAddr=? where _id = ?";
        SQLiteDatabase db = getWritableDatabase();
        db.execSQL(
                sql,
                new Object[] { txl.getTxlName(), txl.getTxlPhone(),
                        txl.getTxlEmail(), txl.getTxlAddr(), txl.get_id() });
        db.close();
    }

    /**
     * 查询全部+根据姓名查询
     *
     * @param name
     * @return
     */
    public List<Tongxunlu> queryName(String name) {
        ArrayList<Tongxunlu> list = new ArrayList<Tongxunlu>();
        String sql = "select * from phone_info";
        if (name != null && !name.equals("")) {
            sql += " where txlName like ‘%" + name + "%‘";
        }
        SQLiteDatabase db = getReadableDatabase();
        Cursor c = db.rawQuery(sql, null);
        while (c.moveToNext()) {
            Tongxunlu txl = new Tongxunlu();
            txl.set_id(c.getInt(0));
            txl.setTxlName(c.getString(1));
            txl.setTxlPhone(c.getString(2));
            txl.setTxlEmail(c.getString(3));
            txl.setTxlAddr(c.getString(4));
            list.add(txl);
        }
        c.close();
        db.close();
        return list;
    }

    /**
     * 根据ID查询
     *
     * @param id
     * @return
     */
    public Tongxunlu qyeryId(int id) {
        Tongxunlu txl = new Tongxunlu();
        String sql = "select * from phone_info where _id =" + id;
        SQLiteDatabase db = getReadableDatabase();
        Cursor c = db.rawQuery(sql, null);
        if (c.moveToNext()) {
            txl.set_id(c.getInt(0));
            txl.setTxlName(c.getString(1));
            txl.setTxlPhone(c.getString(2));
            txl.setTxlEmail(c.getString(3));
            txl.setTxlAddr(c.getString(4));
        }
        c.close();
        db.close();
        return txl;
    }

}