Android--SQLite（增，删，改，查）操作实例代码

需要5个类：

1.实体类：person.java

2.抽象类:sqloperate.java(封装了对数据库的操作)

3.助手类：dbopenhelper.java(继承sqliteopenhelper)

4.实现类:sqloperateimpl.java(实现抽象类sqloperate.java)

5.测试类：test.java(继承androidtestcase)

1.person.java

package com.mrzhu.sqltite;

public class person {

 private int _id;
 private string name;

 public int getid() {
  return _id;
 }

 public void setid(int _id) {
  this._id = _id;
 }

 public string getname() {
  return name;
 }

 public void setname(string name) {
  this.name = name;
 }

 @override
 public string tostring() {
  return "person [id=" + _id + ", name=" + name + "]";
 }

 public person() {
  super();
 }

 public person(int _id, string name) {
  super();
  this._id = _id;
  this.name = name;
 }
}

2.sqloperate.java

package com.mrzhu.sqltite;

import java.util.list;

/**
 * 增删改查
 * @author zlq
 *
 */
public interface sqloperate {
 public void add(person p);
 public void delete(int id);
 public void updata(person p);
 public list<person> find();
 public person findbyid(int id);
}

3.dbopenhelper.java

package com.mrzhu.sqltite;

import android.content.context;
import android.database.sqlite.sqlitedatabase;
import android.database.sqlite.sqliteopenhelper;

/**
 * 助手类
 * @author zlq
 *
 */
public class dbopnehelper extends sqliteopenhelper {

 private static final int version = 1;//版本
 private static final string db_name = "people.db";//数据库名
 public static final string student_table = "student";//表名
 public static final string _id = "_id";//表中的列名
 public static final string name = "name";//表中的列名
 //创建数据库语句，student_table，_id ，name的前后都要加空格
 private static final string create_table = "create table " + student_table + " ( " + _id + " integer primary key autoincrement," + name + " text)";

 public dbopnehelper(context context) {
  super(context, db_name, null, version);
 }

 //数据库第一次被创建时调用
 @override
 public void oncreate(sqlitedatabase db) {
  db.execsql(create_table);
 }

 //版本升级时被调用
 @override
 public void onupgrade(sqlitedatabase db, int oldversion, int newversion) {

 }

}

4.sqloperateimpl.java

package com.mrzhu.sqltite;

import java.util.arraylist;
import java.util.list;

import android.content.contentvalues;
import android.content.context;
import android.database.cursor;
import android.database.sqlite.sqlitedatabase;

public class sqloperateimpl implements sqloperate{

 private dbopnehelper dbopenhelper;

 public sqloperateimpl(context context) {
  dbopenhelper = new dbopnehelper(context);
 }

 /**
  * 增，用insert向数据库中插入数据
  */
 public void add(person p) {
  sqlitedatabase db = dbopenhelper.getwritabledatabase();
  contentvalues values = new contentvalues();
  values.put(dbopnehelper._id, p.getid());
  values.put(dbopnehelper.name, p.getname());
  db.insert(dbopnehelper.student_table, null, values);
 }

 /**
  * 删，通过id删除数据
  */
 public void delete(int id) {
  sqlitedatabase db = dbopenhelper.getwritabledatabase();
  db.delete(dbopnehelper.student_table, dbopnehelper._id + "=?", new string[]{string.valueof(id)});
 }

 /**
  * 改，修改指定id的数据
  */
 public void updata(person p) {
  sqlitedatabase db = dbopenhelper.getwritabledatabase();
  contentvalues values = new contentvalues();
  values.put(dbopnehelper._id, p.getid());
  values.put(dbopnehelper.name, p.getname());
  db.update(dbopnehelper.student_table, values, dbopnehelper._id + "=?", new string[]{string.valueof(p.getid())});
 }

 /**
  * 查，查询表中所有的数据
  */
 public list<person> find() {
  list<person> persons = null;
  sqlitedatabase db = dbopenhelper.getreadabledatabase();
  cursor cursor = db.query(dbopnehelper.student_table, null, null, null, null, null, null);
  if(cursor != null){
   persons = new arraylist<person>();
   while(cursor.movetonext()){
    person person = new person();
    int _id = cursor.getint(cursor.getcolumnindex(dbopnehelper._id));
    string name = cursor.getstring(cursor.getcolumnindex(dbopnehelper.name));
    person.setid(_id);
    person.setname(name);
    persons.add(person);
   }
  }
  return persons;
 }

 /**
  * 查询指定id的数据
  */
 public person findbyid(int id) {
  sqlitedatabase db = dbopenhelper.getreadabledatabase();
  cursor cursor = db.query(dbopnehelper.student_table, null, dbopnehelper._id + "=?", new string[]{string.valueof(id)}, null, null, null);
  person person = null;
  if(cursor != null && cursor.movetofirst()){
   person = new person();
   int _id = cursor.getint(cursor.getcolumnindex(dbopnehelper._id));
   string name = cursor.getstring(cursor.getcolumnindex(dbopnehelper.name));
   person.setid(_id);
   person.setname(name);
  }
  return person;
 }
}

5.test.java

 

在androidmanifest.xml中的<application></application>外添加

（targetpackage是当前工程的包名）

 

 <instrumentation

android:targetpackage="com.mrzhu.sqltite"

android:name="android.test.instrumentationtestrunner">

</instrumentation>

 

在<application></application>中添加<uses-library android:name="android.test.runner"/>

package com.mrzhu.sqltite;

import java.util.list;

import android.test.androidtestcase;
import android.util.log;

public class test extends androidtestcase {
 public void testadd() throws exception{
  sqloperateimpl test = new sqloperateimpl(getcontext());
  person person = new person(2, "peter");
  test.add(person);
 }

 public void testdelete() throws exception{
  sqloperateimpl test = new sqloperateimpl(getcontext());
  test.delete(1);
 }

 public void testupdata() throws exception{
  sqloperateimpl test = new sqloperateimpl(getcontext());
  person person = new person(1, "tom");
  test.updata(person);
 }

 public void testfind() throws exception{
  sqloperateimpl test = new sqloperateimpl(getcontext());
  list<person> persons = test.find();
  for (person person : persons) {
   log.i("system.out", person.tostring());
  }
 }

 public void testfindbyid() throws exception{
  sqloperateimpl test = new sqloperateimpl(getcontext());
  person person = test.findbyid(2);
  log.i("system.out", person.tostring());
 }
}