本文实例讲述了android操作sqlite数据库(增、删、改、查、分页等)及listview显示数据的方法。分享给大家供大家参考，具体如下：
由于刚接触android开发，故此想把学到的基础知识记录一下，以备查询，故此写的比较啰嗦：
步骤如下：
一、介绍：
此文主要是介绍怎么使用android自带的数据库sqlite，以及把后台的数据用listview控件显示
二、新建一个android工程——dbsqliteoperate
工程目录：
三、清单列表androidmanifest.xml的配置为：
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<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.dboperate" android:versioncode="1" android:versionname="1.0" > <uses-sdk android:minsdkversion="8" /> <application android:icon="@drawable/ic_launcher" android:label="@string/app_name" > <!--单元测试 加这句--> <uses-library android:name="android.test.runner" /> <activity android:name=".dbsqliteoperateactivity" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.main" /> <category android:name="android.intent.category.launcher" /> </intent-filter> </activity> </application> <instrumentation android:name="android.test.instrumentationtestrunner" android:targetpackage="com.example.dboperate" android:label="test for my app"/></manifest> |
四、main.xml配置清单：
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<?xml version="1.0" encoding="utf-8"?><linearlayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" > <linearlayout android:layout_width="fill_parent" android:layout_height="wrap_content" android:orientation="horizontal" > <textview android:id="@+id/name" android:layout_width="100dip" android:layout_height="wrap_content" android:text="@string/name" android:gravity="center"/> <textview android:id="@+id/phone" android:layout_width="100dip" android:layout_height="wrap_content" android:text="@string/phone" android:gravity="center"/> <textview android:id="@+id/amount" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="@string/amount" android:gravity="center"/></linearlayout> <listview android:id="@+id/listview" android:layout_width="fill_parent" android:layout_height="fill_parent" > </listview></linearlayout> |
五、item.xml配置清单：
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<?xml version="1.0" encoding="utf-8"?><linearlayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="horizontal" > <textview android:id="@+id/name" android:layout_width="100dip" android:layout_height="wrap_content" android:text="@string/name" android:gravity="center"/> <textview android:id="@+id/phone" android:layout_width="100dip" android:layout_height="wrap_content" android:text="@string/phone" android:gravity="center"/> <textview android:id="@+id/amount" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="@string/amount" android:gravity="center"/></linearlayout> |
六、string.xml配置清单：
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<?xml version="1.0" encoding="utf-8"?><resources> <string name="hello">hello world, dbsqliteoperateactivity!</string> <string name="app_name">exampledbsqliteoperate8</string> <string name="name">姓名</string> <string name="phone">电话</string> <string name="amount">存款</string></resources> |
七、dbsqliteoperateactivity.java activity类的源码：
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package com.example.dboperate;import java.util.arraylist;import java.util.hashmap;import java.util.list;import java.util.map;import com.example.adapter.personadapter;import com.example.domain.person;import com.example.service.personservice;import android.app.activity;import android.database.cursor;import android.os.bundle;import android.view.view;import android.view.view.onclicklistener;import android.widget.adapterview;import android.widget.adapterview.onitemclicklistener;import android.widget.listview;import android.widget.simpleadapter;import android.widget.simplecursoradapter;import android.widget.toast;public class dbsqliteoperateactivity extends activity { listview listview; personservice personservice; onitemclicklistener listviewlistener; /** called when the activity is first created. */ @override public void oncreate(bundle savedinstancestate) { super.oncreate(savedinstancestate); setcontentview(r.layout.main); listviewlistener = new onitemclicklistener(){ @override public void onitemclick(adapterview<?> parent, view view, int position, long id) { //得到listview控件 listview listview = (listview)parent; //1、如果使用自定义适配器，返回的是person对象 //得到该条目数据// person person = (person)listview.getitematposition(position);// //广播出去// toast.maketext(getapplicationcontext(), person.tostring(), toast.length_long).show(); //2、如果使用showlist2()方法中的适配器时，则取得的值是不一样的,返回的是cursor// cursor cursor = (cursor)listview.getitematposition(position);// int personid = cursor.getint(cursor.getcolumnindex("_id"));// toast.maketext(getapplicationcontext(), personid+"", toast.length_long).show(); //3、如果使用showlist()方法中的适配器时，则取得的值是不一样的,返回的是map @suppresswarnings("unchecked") map<string,object> map = (map)listview.getitematposition(position); string name = map.get("name").tostring(); string personid = map.get("personid").tostring(); toast.maketext(getapplicationcontext(), personid +"-"+ name, toast.length_long).show(); } }; listview = (listview) this.findviewbyid(r.id.listview); listview.setonitemclicklistener(listviewlistener); personservice = new personservice(this); showlist(); } private void showlist() { list<person> persons = personservice.getscrolldata(0, 50); list<hashmap<string,object>> data = new arraylist<hashmap<string,object>>(); for(person person : persons){ hashmap<string,object> item = new hashmap<string,object>(); item.put("name", person.getname()); item.put("phone", person.getphone()); item.put("amount", person.getamount()); item.put("personid", person.getid()); data.add(item); } simpleadapter adapter = new simpleadapter(this,data,r.layout.item, new string[]{"name","phone","amount"}, new int[]{r.id.name,r.id.phone,r.id.amount}); listview.setadapter(adapter); } public void showlist2(){ cursor cursor = personservice.getcursorscrolldata(0, 50); //该适配器要求返回的结果集cursor必须包含_id字段，所以需要对取得结果集进行处理 simplecursoradapter adapter = new simplecursoradapter(this,r.layout.item,cursor,new string[]{"name","phone","amount"}, new int[]{r.id.name,r.id.phone,r.id.amount} ); listview.setadapter(adapter); } /** * 自定义适配器 */ public void showlist3(){ list<person> persons = personservice.getscrolldata(0, 50); /** * 第一个参数：上下文context，第二个参数：要显示的数据，第三个参数：绑定的条目界面 */ personadapter adapter = new personadapter(this, persons, r.layout.item); listview.setadapter(adapter); }} |
八、person.java 实体类 源码：
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package com.example.domain;public class person { private integer id; private string name; private string phone; private integer amount; public integer getid() { return id; } public void setid(integer id) { this.id = id; } public string getname() { return name; } public void setname(string name) { this.name = name; } public string getphone() { return phone; } public void setphone(string phone) { this.phone = phone; } public person(string name, string phone) { this.name = name; this.phone = phone; } public person(integer id, string name, string phone,integer amount) { super(); this.id = id; this.name = name; this.phone = phone; this.amount = amount; } public person() { super(); } public integer getamount() { return amount; } public void setamount(integer amount) { this.amount = amount; } @override public string tostring() { return "person [id=" + id + ", name=" + name + ", phone=" + phone + ", amount=" + amount + "]"; }} |
九、dboperatehelper.java 业务类源码：
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package com.example.service;import android.content.context;import android.database.sqlite.sqlitedatabase;import android.database.sqlite.sqlitedatabase.cursorfactory;import android.database.sqlite.sqliteopenhelper;public class dboperatehelper extends sqliteopenhelper { public dboperatehelper(context context) {//默认创建的数据库文件保存在<包名>/database/ //第一个参数是上下文，第二个参数是数据库名称，第三个是游标工厂为null时使用 数据库默认的游标工厂,第四个是数据库版本号但是不能为0，一般大于0 super(context, "smallpig", null, 4); } /** * 数据库每一次被创建时被调用 */ @override public void oncreate(sqlitedatabase sqldb) { sqldb.execsql("create table person(personid integer primary key autoincrement,name varchar(20),phone varchar(12) null)"); } /** * 每一次数据库版本号发生变动时触发此方法 * 比如如果想往数据库中再插入一些表、字段或者其他信息时通过修改数据库版本号来触发此方法 */ @override public void onupgrade(sqlitedatabase db, int oldversion, int newversion) { //db.execsql("alter table person add phone varchar(12) null");\ db.execsql("alter table person add amount integer null"); }} |
十、personservice.java 业务类源码：
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package com.example.service;import java.util.arraylist;import java.util.list;import android.content.context;import android.database.cursor;import android.database.sqlite.sqlitedatabase;import com.example.domain.person;public class personservice { private dboperatehelper dboperatehelper; public personservice(context context) { this.dboperatehelper = new dboperatehelper(context); } /** * 保存记录 * @param person */ public void save(person person){ //得到数据库实例，里面封装了数据库操作方法 sqlitedatabase sqldb = dboperatehelper.getwritabledatabase(); //sqldb.execsql("insert into person(name,phone) values('"+person.getname()+"','"+person.getphone()+"')"); //利用占位符可以避免注入，但是注意数组参与与占位符对应的字段要一一对应 sqldb.execsql("insert into person(name,phone,amount) values(?,?,?)",new object[]{person.getname(),person.getphone(),person.getamount()}); //关闭数据库 sqldb.close(); } /** * 删除记录 * @param id */ public void delete(integer id){ sqlitedatabase sqldb = dboperatehelper.getwritabledatabase(); sqldb.execsql("delete from person where personid=?",new object[]{id}); sqldb.close(); } /** * 更新记录 * @param person */ public void update(person person){ sqlitedatabase sqldb = dboperatehelper.getwritabledatabase(); sqldb.execsql("update person set name=?,phone=?,amount=? where personid=?",new object[]{person.getname(),person.getphone(),person.getamount(),person.getid()}); sqldb.close(); } /** * 通过id查询记录 * @param id * @return */ public person find(integer id){ /** * getwritabledatabase 与 getreadabledatabase 的区别： * getreadabledatabase会先返回getwritabledatabase(可写)，如果调用getwritabledatabase失败 * 则才会调用getreadabledatabase后续方法，使数据库只读 * 当写入的数据超过数据库大小则调用getwritabledatabase会失败 * 所以只读时则可以使用此方法，其它情况(只要不是超过数据库大小)也可以使用此方法 */ sqlitedatabase sqldb = dboperatehelper.getreadabledatabase(); cursor cursor = sqldb.rawquery("select * from person where personid=?", new string[]{string.valueof(id)}); int personid; string name; string phone; int amount; person person = null; if(cursor.movetofirst()){ personid = cursor.getint(cursor.getcolumnindex("personid")); name = cursor.getstring(cursor.getcolumnindex("name")); phone = cursor.getstring(cursor.getcolumnindex("phone")); amount = cursor.getint(cursor.getcolumnindex("amount")); person = new person(personid,name,phone,amount); } cursor.close(); return person; } /** * 返回指定长度记录，limit 3,5,适用于分页 * @param offset 起始 * @param maxresult 长度 * @return */ public list<person> getscrolldata(int offset,int maxresult){ sqlitedatabase sqldb = dboperatehelper.getreadabledatabase(); cursor cursor = sqldb.rawquery("select * from person order by personid asc limit ?,?", new string[]{string.valueof(offset),string.valueof(maxresult)}); int personid; string name; string phone; int amount; person person = null; list<person> persons = new arraylist<person>(); while(cursor.movetonext()){ personid = cursor.getint(cursor.getcolumnindex("personid")); name = cursor.getstring(cursor.getcolumnindex("name")); phone = cursor.getstring(cursor.getcolumnindex("phone")); amount = cursor.getint(cursor.getcolumnindex("amount")); person = new person(personid,name,phone,amount); persons.add(person); } cursor.close(); return persons; } /** * 返回cursor * @param offset 起始 * @param maxresult 长度 * @return */ public cursor getcursorscrolldata(int offset,int maxresult){ sqlitedatabase sqldb = dboperatehelper.getreadabledatabase(); cursor cursor = sqldb.rawquery("select personid as _id,name,phone,amount from person order by personid asc limit ?,?", new string[]{string.valueof(offset),string.valueof(maxresult)}); return cursor; } /** * 返回总记录数 * @return */ public long getcount(){ sqlitedatabase sqldb = dboperatehelper.getreadabledatabase(); cursor cursor = sqldb.rawquery("select count(*) from person", null); //该查询语句值返回一条语句 cursor.movetofirst(); long result = cursor.getlong(0); cursor.close(); return result; } public void payment(){ sqlitedatabase sqldb = dboperatehelper.getwritabledatabase(); sqldb.begintransaction();//开启事务 try{ sqldb.execsql("update person set amount = amount -10 where personid=1"); sqldb.execsql("update person set amount = amount + 10 where personid=2"); sqldb.settransactionsuccessful();//设置事务标志位true } finally { //结束事务：有两种情况：commit\rollback，事务提交或者回滚是由事务的标识决定的 //事务为ture则提交，事务为flase则回滚，默认为false sqldb.endtransaction(); } }} |
十一、otherpersonservice.java 业务类源码：
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package com.example.service;import java.util.arraylist;import java.util.list;import com.example.domain.person;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.sqliteopenhelper;public class otherpersonservice { private dboperatehelper dboperatehelper; public otherpersonservice(context context) { this.dboperatehelper = new dboperatehelper(context); } /** * 保存记录 * @param person */ public void save(person person){ //得到数据库实例，里面封装了数据库操作方法 sqlitedatabase sqldb = dboperatehelper.getwritabledatabase(); //sqldb.execsql("insert into person(name,phone) values('"+person.getname()+"','"+person.getphone()+"')"); //利用占位符可以避免注入，但是注意数组参与与占位符对应的字段要一一对应 //sqldb.execsql("insert into person(name,phone) values(?,?)",new object[]{person.getname(),person.getphone()}); contentvalues values = new contentvalues(); values.put("name", person.getname()); values.put("phone", person.getphone()); values.put("amount", person.getamount()); //第一个参数是表名，第三个为字段值集合，第二个参数是空值字段，当第三个字段值集合为空时，系统会自动插入一条第二个参数为空的sql语句 //否则当第三个参数为空时，如果第二个参数也为空，那么插入表就会找不到插入的字段信息，会报错 sqldb.insert("person", "name", values ); //关闭数据库 sqldb.close(); } /** * 删除记录 * @param id */ public void delete(integer id){ sqlitedatabase sqldb = dboperatehelper.getwritabledatabase(); //sqldb.execsql("delete from person where personid=?",new object[]{id}); //第一个参数是表名，第二个是where后面的条件用占位符表示，第三个对应占位符为参数值 sqldb.delete("person", "personid=?", new string[]{integer.tostring(id)}); sqldb.close(); } /** * 更新记录 * @param person */ public void update(person person){ sqlitedatabase sqldb = dboperatehelper.getwritabledatabase(); //sqldb.execsql("update person set name=?,phone=? where personid=?",new object[]{person.getname(),person.getphone(),person.getid()}); //第一个参数为表名，第二个是一个更新值集合，采用键值对的形式，每个更新的字段对应更新值 //第三个参数是where后面条件字段用占位符标识，第四个参数是对应where占位符的值 contentvalues values = new contentvalues(); values.put("name", person.getname()); values.put("phone", person.getphone()); values.put("amount", person.getamount()); sqldb.update("person", values , "personid=?", new string[]{person.getid().tostring()}); sqldb.close(); } /** * 通过id查询记录 * @param id * @return */ public person find(integer id){ /** * getwritabledatabase 与 getreadabledatabase 的区别： * getreadabledatabase会先返回getwritabledatabase(可写)，如果调用getwritabledatabase失败 * 则才会调用getreadabledatabase后续方法，使数据库只读 * 当写入的数据超过数据库大小则调用getwritabledatabase会失败 * 所以只读时则可以使用此方法，其它情况(只要不是超过数据库大小)也可以使用此方法 */ sqlitedatabase sqldb = dboperatehelper.getreadabledatabase(); //cursor cursor = sqldb.rawquery("select * from person where personid=?", new string[]{string.valueof(id)}); //第一个参数是表名；第二个参数是查询显示的字段，null时默认查询显示所有字段； //第三个参数是where查询条件占位符；第四个是占位符对应的值； //第五个参数是group by条件；第六个是having条件；第七个是order by条件 cursor cursor = sqldb.query("person", null, "personid=?", new string[]{id.tostring()}, null, null, null); int personid; string name; string phone; int amount; person person = null; if(cursor.movetofirst()){ personid = cursor.getint(cursor.getcolumnindex("personid")); name = cursor.getstring(cursor.getcolumnindex("name")); phone = cursor.getstring(cursor.getcolumnindex("phone")); amount = cursor.getint(cursor.getcolumnindex("amount")); person = new person(personid,name,phone,amount); } cursor.close(); return person; } /** * 返回指定长度记录，limit 3,5,适用于分页 * @param offset 起始 * @param maxresult 长度 * @return */ public list<person> getscrolldata(int offset,int maxresult){ sqlitedatabase sqldb = dboperatehelper.getreadabledatabase(); //cursor cursor = sqldb.rawquery("select * from person order by personid asc limit ?,?", new string[]{string.valueof(offset),string.valueof(maxresult)}); //第一个参数是表名；第二个参数是查询显示的字段，null时默认查询显示所有字段； //第三个参数是where查询条件占位符；第四个是占位符对应的值； //第五个参数是group by条件；第六个是having条件；第七个是order by条件 //第八个参数是limit ?,? 条件 cursor cursor = sqldb.query("person", null, null, null, null, null, "personid",offset+","+maxresult); int personid; string name; string phone; int amount; person person = null; list<person> persons = new arraylist<person>(); while(cursor.movetonext()){ personid = cursor.getint(cursor.getcolumnindex("personid")); name = cursor.getstring(cursor.getcolumnindex("name")); phone = cursor.getstring(cursor.getcolumnindex("phone")); amount = cursor.getint(cursor.getcolumnindex("amount")); person = new person(personid,name,phone,amount); persons.add(person); } cursor.close(); return persons; } /** * 返回总记录数 * @return */ public long getcount(){ sqlitedatabase sqldb = dboperatehelper.getreadabledatabase(); //cursor cursor = sqldb.rawquery("select count(*) from person", null); //第一个参数是表名；第二个参数是查询显示的字段，null时默认查询显示所有字段； //第三个参数是where查询条件占位符；第四个是占位符对应的值； //第五个参数是group by条件；第六个是having条件；第七个是order by条件 cursor cursor = sqldb.query("person", new string[]{"count(*)"}, null, null, null, null, null); //该查询语句值返回一条语句 cursor.movetofirst(); long result = cursor.getlong(0); cursor.close(); return result; }} |
十二、personservicetest.java 单元测试类源码：
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package com.example.test;import java.util.list;import com.example.domain.person;import com.example.service.dboperatehelper;import com.example.service.personservice;import android.test.androidtestcase;import android.util.log;public class personservicetest extends androidtestcase { public void testcreatedb() throws exception{ dboperatehelper dbhelper = new dboperatehelper(getcontext()); dbhelper.getwritabledatabase(); } public void testsave() throws exception{ personservice ps = new personservice(getcontext()); for(int i=1;i<=100;i++){ person person = new person(); person.setname("我是"+i); person.setphone(string.valueof(long.parselong("18888888800")+i)); ps.save(person); log.i("personservice",person.tostring()); } } public void testdelete() throws exception{ personservice ps = new personservice(getcontext()); ps.delete(10); } public void testupdate() throws exception{ personservice ps = new personservice(getcontext()); ps.update(new person(1,"xiaopang","18887654321",0)); } public void testfind() throws exception{ personservice ps = new personservice(getcontext()); person person = ps.find(1); log.i("personservice", person.tostring()); } public void testgetscrolldata() throws exception{ personservice ps = new personservice(getcontext()); list<person> persons = ps.getscrolldata(3, 5); for(person person:persons){ log.i("personservice",person.tostring()); } } public void testgetcount() throws exception{ personservice ps = new personservice(getcontext()); long count = ps.getcount(); log.i("personservice",count.tostring()); } public void testupdateamount() throws exception{ personservice ps = new personservice(getcontext()); person person1 = ps.find(1); person person2 = ps.find(2); person1.setamount(100); person2.setamount(100); ps.update(person1); ps.update(person2); } public void testpayment() throws exception{ personservice ps = new personservice(getcontext()); ps.payment(); }} |
十三、otherpersonservicetest 单元测试类源码：
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package com.example.test;import java.util.list;import com.example.domain.person;import com.example.service.dboperatehelper;import com.example.service.otherpersonservice;import android.test.androidtestcase;import android.util.log;public class otherpersonservicetest extends androidtestcase { public void testcreatedb() throws exception{ dboperatehelper dbhelper = new dboperatehelper(getcontext()); dbhelper.getwritabledatabase(); } public void testsave() throws exception{ otherpersonservice ps = new otherpersonservice(getcontext()); for(int i=1;i<=100;i++){ person person = new person(); person.setname("我是"+i); person.setphone(string.valueof(long.parselong("18888888800")+i)); ps.save(person); log.i("personservice",person.tostring()); } } public void testdelete() throws exception{ otherpersonservice ps = new otherpersonservice(getcontext()); ps.delete(10); } public void testupdate() throws exception{ otherpersonservice ps = new otherpersonservice(getcontext()); ps.update(new person(1,"xiaopang","18887654321",0)); } public void testfind() throws exception{ otherpersonservice ps = new otherpersonservice(getcontext()); person person = ps.find(1); log.i("personservice", person.tostring()); } public void testgetscrolldata() throws exception{ otherpersonservice ps = new otherpersonservice(getcontext()); list<person> persons = ps.getscrolldata(3, 5); for(person person:persons){ log.i("personservice",person.tostring()); } } public void testgetcount() throws exception{ otherpersonservice ps = new otherpersonservice(getcontext()); long count = ps.getcount(); log.i("personservice",count.tostring()); }} |
十四、注意事项以及相关知识点：
1、掌握sqlite数据库如何创建数据库、建立表、维护字段等操作
继承sqliteopenhelper类，构造函数调用父类构造函数创建数据库，利用oncreate创建表，利用onupgrade更新表字段信息
2、掌握sqlite数据库如何增、删、改、查以及分页
取得sqlitedatabase的实例，然后调用该实例的方法可以完成上述操作
sqlitedatabase提供两种操作上述功能的方式：一是直接调用execsql书写sql语句，另一种是通过insert、update、delete、query等方法来传值来拼接sql，前一种适合熟练掌握sql 语句的
3、对需要数据同步的处理请添加事务处理，熟悉事务的处理方式
4、了解各个方法参数的意义以及传值
5、掌握listview显示后台数据的使用方法
simpleadapter、simplecursoradapter以及自定义适配器的使用，以及onitemclicklistener取值时各个适配器返回值的区别以及取值方法
6、多学、多记、多练、多思，加油！
希望本文所述对大家android程序设计有所帮助。
