void QueryImage(Context context){

? //①得到ContentResolver對(duì)象

?ContentResolver cr = context.getContentResover();

? Uri uri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;

? //②查詢(xún)數(shù)據(jù)庫(kù)

? Cursorcursor = MediaStore.Images.Media.query(cr,uri,null);

?cursor.moveToFirst();//③移動(dòng)游標(biāo)到頭部

? ......//從游標(biāo)中取出數(shù)據(jù)集

??cursor.close();//④關(guān)閉游標(biāo)

}

public ContentResolver getContentResolver() {

?? returnmContentResolver;

}

final void init(LoadedApk packageInfo, IBinder activityToken,

?????? ActivityThreadmainThread, Resources container,String basePackageName) {

? ?......

??mMainThread = mainThread;//mainThread指向AcitivityThread對(duì)象

? //mContentResolver的真實(shí)類(lèi)型是ApplicationContentResolver

??mContentResolver = new ApplicationContentResolver(this, mainThread);

?? ......

?}

提示為了書(shū)寫(xiě)方便，將ContentProvider簡(jiǎn)稱(chēng)為CP，將ContentResolver簡(jiǎn)稱(chēng)為CR。

提示MediaStore類(lèi)較為復(fù)雜，主要原因是它定義了一些同名類(lèi)。讀者閱讀代碼時(shí)務(wù)須仔細(xì)。

public static final class Media implementsImageColumns {

?? public static final Cursor query(ContentResolvercr,Uri uri,

?????????????????????????????????????????? String[]projection) {

? ?//直接調(diào)用ContentResolver的query函數(shù)

?? returncr.query(uri, projection, null,

???????????????????? ?null,DEFAULT_SORT_ORDER);

?}

提示追求運(yùn)行效率的程序員也許會(huì)對(duì)上邊這段代碼的實(shí)現(xiàn)略有微詞，因?yàn)镮mage.Media的query函數(shù)基本上沒(méi)做任何有意義的工作。假如客戶(hù)端直接調(diào)用cr.query函數(shù)，則此處的query就增加了一次函數(shù)調(diào)用和返回的開(kāi)銷(xiāo)（即Image.Media query調(diào)用和返回時(shí)參數(shù)的入棧/出棧）。但是，通過(guò)Image.Media的封裝將使程序更清晰和易讀（與直接使用ContentResolver的query相比，代碼閱讀者一看Image.Media就知道其query函數(shù)應(yīng)該和Image有關(guān)，否則需要通過(guò)解析uri參數(shù)才能確定查詢(xún)的信息是什么）。代碼清晰易讀和運(yùn)行效率高，往往是軟件開(kāi)發(fā)中的熊掌和魚(yú)，它們之間的對(duì)立性，將在本章中體現(xiàn)得淋漓盡致。筆者建議讀者在實(shí)際開(kāi)發(fā)中結(jié)合具體情況決定取舍，萬(wàn)不可鉆牛角尖。

public final Cursor query(Uri uri, String[]projection,

???????????String selection, String[] selectionArgs, String sortOrder) {

?? //調(diào)用acquireProvider函數(shù)，參數(shù)為uri，函數(shù)也由ContentResolver實(shí)現(xiàn)

??IContentProvider provider = acquireProvider(uri);

? //注意：下面將和ContentProvider交互， 相關(guān)知識(shí)留待7.4節(jié)再分析

?? ......

?}

public final IContentProvider acquireProvider(Uriuri) {

??if(!SCHEME_CONTENT.equals(uri.getScheme()))?return null;

? Stringauth = uri.getAuthority();

? if (auth!= null) {

???? //acquireProvider是一個(gè)抽象函數(shù)，由ContentResolver的子類(lèi)實(shí)現(xiàn)。在本例中，該函數(shù)

???? //將由ApplicationContentResolver實(shí)現(xiàn)。uri.getAuthority將返回代表目標(biāo)

??? ?//ContentProvider的名字

????? returnacquireProvider(mContext, uri.getAuthority());

? }

? returnnull;

?}

protected IContentProvider acquireProvider(Contextcontext, String name) {

???//mMainThread指向代表應(yīng)用進(jìn)程主線(xiàn)程的ActivityThread對(duì)象，每個(gè)應(yīng)用進(jìn)程只有一個(gè)

???//ActivityThread對(duì)象

?? ?return mMainThread.acquireProvider(context,name);

?}

public final IContentProvideracquireProvider(Context c, String name) {

? //①調(diào)用getProvider函數(shù)，它很重要。見(jiàn)下文分析

??IContentProvider provider = getProvider(c,name);

? ......

? IBinderjBinder = provider.asBinder();

??synchronized(mProviderMap) {

???? //客戶(hù)端進(jìn)程將本進(jìn)程使用的ContentProvider信息保存到mProviderRefCountMap中，

???? //其主要功能與引用計(jì)數(shù)和資源釋放有關(guān)，讀者暫可不理會(huì)它

?????ProviderRefCount prc = mProviderRefCountMap.get(jBinder);

????? if(prc== null)

???????? ?mProviderRefCountMap.put(jBinder, newProviderRefCount(1));

?????else?? prc.count++;

?? }

?returnprovider;

}

private IContentProvider getProvider(Contextcontext, String name) {

? /*

?? 查詢(xún)?cè)搼?yīng)用進(jìn)程是否已經(jīng)保存了用于和遠(yuǎn)端ContentProvider通信的對(duì)象existing。

?? 此處，我們知道existing的類(lèi)型是IContentProvider，不過(guò)IContentProvider是一

?? 個(gè)interface，那么existing的真實(shí)類(lèi)型是什么呢？稍后再揭示

? */

?IContentProvider existing = getExistingProvider(context, name);

? if(existing != null) return existing;//如果existing存在，則直接返回

?

?IActivityManager.ContentProviderHolder holder = null;

? try {

????? //如果existing不存在，則需要向AMS查詢(xún)，返回值的類(lèi)型為ContentProviderHolder

????? holder= ActivityManagerNative.getDefault().getContentProvider(

???????????????getApplicationThread(), name);

? }......

?? //注意：記住下面這個(gè)函數(shù)調(diào)用，此時(shí)是在客戶(hù)端進(jìn)程中

?IContentProvider prov = installProvider(context, holder.provider,

???????????????holder.info, true);

?? ......

? returnprov;

?}

?privatefinal ContentProviderHolder getContentProviderImpl(

?????? ???????????????????IApplicationThread caller, String name) {

?ContentProviderRecord cpr;

?ProviderInfo cpi = null;

?

?synchronized(this) {

????ProcessRecord r = null;

???? if(caller != null) {

????????? r= getRecordForAppLocked(caller);

??????????if (r == null)......//如果查詢(xún)不到調(diào)用者信息，則拋出SecurityException

? ????}// if (caller != null)判斷結(jié)束

??? //name參數(shù)為調(diào)用進(jìn)程指定的代表目標(biāo)ContentProvider的authority

??? cpr =mProvidersByName.get(name);

??? //如果cpr不為空，表明該ContentProvider已經(jīng)在AMS中注冊(cè)

??? booleanproviderRunning = cpr != null;

??? if(providerRunning){

???????......//如果該ContentProvider已經(jīng)存在，則進(jìn)行對(duì)應(yīng)處理, 相關(guān)內(nèi)容可自行閱讀

??? }

?? //如果目標(biāo)ContentProvider對(duì)應(yīng)進(jìn)程還未啟動(dòng)

?? if(!providerRunning) {

????? ?try {

???????????//查詢(xún)PKMS，得到指定的ProviderInfo信息

???????????cpi = AppGlobals.getPackageManager().resolveContentProvider(

???????????????????name,STOCK_PM_FLAGS |

???????????????????PackageManager.GET_URI_PERMISSION_PATTERNS);

?????? ?}......

??????? String msg;

????? //權(quán)限檢查，此處不作討論

????? if((msg=checkContentProviderPermissionLocked(cpi, r)) != null)

?????????throw new SecurityException(msg);

???? /*

????? 如果system_server還沒(méi)啟動(dòng)完畢，并且該ContentProvider不運(yùn)行在system_server

????? 中，則此時(shí)不允許啟動(dòng)ContentProvider。讀者還記得哪個(gè)ContentProvider運(yùn)行在

?????system_server進(jìn)程中嗎？答案是SettingsProvider

? ??*/

???? .......

?

????ComponentName comp = new ComponentName(cpi.packageName, cpi.name);

???? cpr =mProvidersByClass.get(comp);

???? finalboolean firstClass = cpr == null;

???? //初次啟動(dòng)MediaProvider對(duì)應(yīng)進(jìn)程時(shí)，firstClass一定為true

??? ?if (firstClass) {

????? ???try {

?????????????//查詢(xún)PKMS，得到MediaProvider所在的Application信息

???????? ?????ApplicationInfoai =

??????????????????????AppGlobals.getPackageManager().getApplicationInfo(

??????????????????????????cpi.applicationInfo.packageName, STOCK_PM_FLAGS);

?????????? ??if (ai == null) return null;

????????????//在AMS內(nèi)部通過(guò)ContentProviderRecord來(lái)保存ContentProvider的信息，類(lèi)似

????????????//ActivityRecord，BroadcastRecord等

????????? ???cpr = new ContentProviderRecord(cpi, ai,comp);

?????? ??}......

??? }// if(firstClass)判斷結(jié)束

?? /*

?? canRunHere函數(shù)用于判斷目標(biāo)CP能否運(yùn)行在r所對(duì)應(yīng)的進(jìn)程（即調(diào)用者所在進(jìn)程）

?? 該函數(shù)內(nèi)部做如下判斷：

?? (info.multiprocess|| info.processName.equals(app.processName))

????&& (uid == Process.SYSTEM_UID || uid == app.info.uid)

?? ?就本例而言，MediaProvider不能運(yùn)行在客戶(hù)端進(jìn)程中

?? */

??? if (r !=null && cpr.canRunHere(r)) ?returncpr;

?

??? finalint N = mLaunchingProviders.size();

??? ......//查找目標(biāo)ContentProvider對(duì)應(yīng)的進(jìn)程是否正處于啟動(dòng)狀態(tài)

??? //如果i大于等于N，表明目標(biāo)進(jìn)程的信息不在mLaunchingProviders中

??? if (i>= N) {

?????? finallong origId = Binder.clearCallingIdentity();

?????? ......

?????? //調(diào)用startProcessLocked函數(shù)創(chuàng)建目標(biāo)進(jìn)程

??????ProcessRecord proc = startProcessLocked(cpi.processName,

???????????????????????? cpr.appInfo, false, 0,"content provider",

???????????????????????? newComponentName(cpi.applicationInfo.packageName,

????????????????????????? cpi.name), false);

?????? if(proc == null)return null;

??????cpr.launchingApp = proc;

?????? //將該進(jìn)程信息保存到mLaunchingProviders中

??????mLaunchingProviders.add(cpr);

??? }

?

???? if(firstClass) mProvidersByClass.put(comp, cpr);

????mProvidersByName.put(name, cpr);

???? /*

?????? 下面這個(gè)函數(shù)將為客戶(hù)端進(jìn)程和目標(biāo)CP進(jìn)程建立緊密的關(guān)系，即當(dāng)目標(biāo)CP進(jìn)程死亡后，

??????? AMS將根據(jù)該函數(shù)建立的關(guān)系找到客戶(hù)端進(jìn)程并殺死（kill）它們。在7.2.3節(jié)

?????? ?有對(duì)這個(gè)函數(shù)的相關(guān)解釋

???? */

???? incProviderCount(r, cpr);

???? if(cpr.launchingApp == null) return null;

???? try {

??????????cpr.wait();//等待目前進(jìn)程的啟動(dòng)

????? } ......

?? }// synchronized(this)結(jié)束

? returncpr;

}

private final booleanattachApplicationLocked(IApplicationThread thread,

???????????int pid) {

?? ......

?? //通過(guò)PKMS查詢(xún)運(yùn)行在該進(jìn)程中的CP信息，并保存到mProvidersByClass中

?? Listproviders = normalMode ?

???????????????generateApplicationProvidersLocked(app) : null;

? //調(diào)用目標(biāo)應(yīng)用進(jìn)程的bindApplication函數(shù)，此處將providers信息傳遞給目標(biāo)進(jìn)程

?? thread.bindApplication(processName,appInfo, providers,

?????????????????????????????app.instrumentationClass, profileFile,

???????????????????? ?????????......);

?? ......

}

private void handleBindApplication(AppBindDatadata) {

?? ......

?? if(!data.restrictedBackupMode){

???????List<ProviderInfo> providers = data.providers;

??????? if(providers != null) {

???????????//調(diào)用installContentProviders安裝

???????????installContentProviders(app, providers);

???????????......

?????? }

? ?}

?? ......

}

private void installContentProviders(Contextcontext,

????? ????????????????????????????????????????List<ProviderInfo>providers) {

?

? finalArrayList<IActivityManager.ContentProviderHolder> results =

????????? ??????newArrayList<IActivityManager.ContentProviderHolder>();

?Iterator<ProviderInfo> i = providers.iterator();

? while(i.hasNext()) {

???? //①也調(diào)用installProvider，注意該函數(shù)傳遞的第二個(gè)參數(shù)為null

????IContentProvider cp = installProvider(context, null, cpi, false);

???? if (cp!= null) {

?????????IActivityManager.ContentProviderHolder cph =

??????????? ??????????????newIActivityManager.ContentProviderHolder(cpi);

?????????cph.provider = cp;

??????????results.add(cph);//將信息添加到results數(shù)組中

?????????? ......//創(chuàng)建引用計(jì)數(shù)

???????? }

??? }//while循環(huán)結(jié)束

?

??? try {? //②調(diào)用AMS的publishContentProviders發(fā)布ContentProviders

???????????ActivityManagerNative.getDefault().publishContentProviders(

???????????????getApplicationThread(), results);

??????? } ......

?}

private IContentProvider installProvider(Contextcontext,

???????????IContentProvider provider, ProviderInfo info, boolean noisy) {

??ContentProvider localProvider = null;

?? if(provider == null) {//針對(duì)目標(biāo)進(jìn)程的情況

???????Context c = null;

????????ApplicationInfo ai = info.applicationInfo;

???????? if(context.getPackageName().equals(ai.packageName)) {

???????????????c = context;

???????????}......//這部分代碼已經(jīng)在6.2.3節(jié)分析過(guò)了，其目的就是為了得到正確的

??????????//Context用于加載Java字節(jié)碼

???????? try{

????????????final java.lang.ClassLoader cl = c.getClassLoader();

????????????//通過(guò)Java反射機(jī)制創(chuàng)建MediaProvider實(shí)例

????????????localProvider = (ContentProvider)cl.

?????????????????????????????????????loadClass(info.name).newInstance();

????????????//注意下面這句代碼

????????????provider = localProvider.getIContentProvider();

??????????? }

???? } elseif (localLOGV) {

???????????Slog.v(TAG, "Installing external provider " + info.authority +": "

???????????????????+ info.name);

??? }// if(provider == null)判斷結(jié)束

??? /*

???? 由以上代碼可知，對(duì)于provider不為null 的情況（即客戶(hù)端調(diào)用的情況），該函數(shù)沒(méi)有

???? 什么特殊的處理

??? */

??? ......

???? /*

????? 引用計(jì)數(shù)及設(shè)置DeathReceipient等相關(guān)操作。在6.2.3節(jié)的第2個(gè)小標(biāo)題中

????? 曾說(shuō)過(guò)，目標(biāo)進(jìn)程為自己進(jìn)程中的CP實(shí)例設(shè)置DeathReceipient沒(méi)有作用，因?yàn)槎咴谕粋€(gè)

????? 進(jìn)程中，自己怎么能接收自己的訃告消息呢？不過(guò)，如果客戶(hù)端進(jìn)程為目標(biāo)進(jìn)程的CP設(shè)置

???? DeathReceipient又有作用嗎？仔細(xì)思考這個(gè)問(wèn)題

??? */

??? returnprovider;//最終返回的對(duì)象是IContentProvider類(lèi)型，它到底是什么呢？

?}

public Cursor query(Uri uri, String[] projection,

???????????????String selection, String[] selectionArgs, String sortOrder) {

??enforceReadPermission(uri);

??//Transport為ContentProvider的內(nèi)部類(lèi)，此處將調(diào)用ContentProvider的query函數(shù)

?? //本例中，該query函數(shù)由MediaProvider實(shí)現(xiàn)，故最終會(huì)調(diào)用MediaProvider的query

?? returnContentProvider.this.query(uri, projection, selection,

???????????????????selectionArgs, sortOrder);

?}

public final voidpublishContentProviders(IApplicationThread caller,

?????????List<ContentProviderHolder> providers) {

?? ......

??synchronized(this) {

???? finalProcessRecord r = getRecordForAppLocked(caller);

???? finallong origId = Binder.clearCallingIdentity();

?

??? ?final int N = providers.size();

??? ?for (int i=0; i<N; i++) {

???????ContentProviderHolder src = providers.get(i);

???????ContentProviderRecord dst = r.pubProviders.get(src.info.name);

?????? if(dst != null) {

????????? ?......//將相關(guān)信息分別保存到mProviderByClass和mProvidersByName中

???????? ??int NL = mLaunchingProviders.size();

?????????...... //目標(biāo)進(jìn)程已經(jīng)啟動(dòng)，將其從mLaunchingProviders移除

?????????synchronized (dst) {

????????????dst.provider = src.provider;//將信息保存在dst中

????????????dst.proc = r;

???????????//觸發(fā)還等在（wait）getContentProvider中的那個(gè)客戶(hù)端進(jìn)程

????????????dst.notifyAll();

? ????????}

????? ?updateOomAdjLocked(r);//調(diào)節(jié)目標(biāo)進(jìn)程的oom_adj等相關(guān)參數(shù)

???? }// if(dst != null)判斷結(jié)束

?? ......

?? }

}

提示讀者可能覺(jué)得，這條路線(xiàn)是對(duì)第6章的補(bǔ)充和延續(xù)。不過(guò)，雖然目標(biāo)進(jìn)程由AMS創(chuàng)建和啟動(dòng)，而且ContentProvider的發(fā)布也需和AMS交互，但是對(duì)于ContentProvider來(lái)說(shuō)，我們更關(guān)注客戶(hù)端和目標(biāo)進(jìn)程中ContentProvider實(shí)例間的交互。事實(shí)上，客戶(hù)端得到IContentProvider Bp端對(duì)象后，即可直接與目標(biāo)進(jìn)程的CP實(shí)例交互，也就無(wú)需借助AMS了，所以筆者將這條路線(xiàn)放到了本章進(jìn)行分析。

注意本書(shū)后文所說(shuō)的SQLite API特指libsqlite.so提供的Native層的API。

#include <unistd.h>

#include <sqlite3.h> //包含sqlite API頭文件，這里的3是SQLite的版本號(hào)

#include <stdlib.h>

?

#define LOG_TAG "SQLITE_TEST"? //定義該進(jìn)程logcat輸出的標(biāo)簽

#include <utils/Log.h>

#ifndef NULL

?? #defineNULL (0)

#endif

//聲明數(shù)據(jù)庫(kù)文件的路徑

#define DB_PATH"/mnt/sdcard/sqlite3test.db"

/*

?? 聲明一個(gè)全局的SQLite句柄，開(kāi)發(fā)者無(wú)需了解該數(shù)據(jù)結(jié)構(gòu)的具體內(nèi)容，只要知道它代表了使用者

?? 和數(shù)據(jù)庫(kù)的一種連接關(guān)系即可。以后凡是針對(duì)特定數(shù)據(jù)庫(kù)的操作，都需要傳入對(duì)應(yīng)的SQLite句柄

*/

static sqlite3* g_pDBHandle = NULL;

?

/*

?? 定義一個(gè)宏，用于檢測(cè)SQLite API調(diào)用的返回值，如果value不等于expectValue，則打印警告，

?? 并退出程序。注意，進(jìn)程退出后，系統(tǒng)會(huì)自動(dòng)回收分配的內(nèi)存資源。對(duì)如此簡(jiǎn)單的例子來(lái)說(shuō)，讀者大可

??? 不必苛責(zé)。其中，sqlite3_errmsg函數(shù)用于打印錯(cuò)誤信息

*/

#define CHECK_DB_ERR(value,expectValue) \

do \

{ \

?? if(value!= expectValue)\

?? {\

????LOGE("Sqlite db fail:%s",g_pDBHandle==NULL?"db not \

??? ???????connected":sqlite3_errmsg(g_pDBHandle));\

????exit(0);\

?? }\

}while(0)

?

?

int main(int argc, char* argv[])

{

??LOGD("Delete old DB file");

??unlink(DB_PATH);//先刪除舊的數(shù)據(jù)庫(kù)文件

??LOGD("Create new DB file");

?? /*

??? 調(diào)用sqlite3_open創(chuàng)建一個(gè)數(shù)據(jù)庫(kù)，并將和該數(shù)據(jù)庫(kù)的連接環(huán)境保存在全局的SQLite句柄

???? g_pDBHandle中，以后操作g_pDBHandle就是操作DB_PATH對(duì)應(yīng)的數(shù)據(jù)庫(kù)

??? */

?? int ret =sqlite3_open(DB_PATH,&g_pDBHandle);

??CHECK_DB_ERR(ret,SQLITE_OK);

??

??LOGD("Create Table personal_info:");

?? /*

??? 定義宏TABLE_PERSONAL_INFO，用于描述為本例數(shù)據(jù)庫(kù)建立一個(gè)表所用的SQL語(yǔ)句，

??? 不熟悉SQL語(yǔ)句的讀者可先學(xué)習(xí)相關(guān)知識(shí)。從該宏的定義可知，將建立一個(gè)名為

???personal_info的表，該表有4列，第一列是主鍵，類(lèi)型是整型（SQLite中為INTEGER），

??? 每加入一行數(shù)據(jù)該值會(huì)自動(dòng)遞增；第二列名為"name"，數(shù)據(jù)類(lèi)型是字符串（SQLite中為T(mén)EXT）；

???? 第三列名為“age”，數(shù)據(jù)類(lèi)型是整型；第四列名為“sex”，數(shù)據(jù)類(lèi)型是字符串

?? */

?? #defineTABLE_PERSONAL_INFO? \

?? ???????"CREATETABLE personal_info" \

?? ????????"(ID INTEGER primary keyautoincrement," \

?????????? "nameTEXT," \

?? ????????"age INTEGER,"\

?? ????????"sex TEXT"\

?? ????????")"

?? //打印TABLE_PERSONAL_INFO所對(duì)應(yīng)的SQL語(yǔ)句

??LOGD("\t%s\n",TABLE_PERSONAL_INFO);

? //調(diào)用sqlite3_exec執(zhí)行前面那條SQL語(yǔ)句

?? ret =sqlite3_exec(g_pDBHandle,TABLE_PERSONAL_INFO,NULL,NULL,NULL);

??CHECK_DB_ERR(ret,SQLITE_OK);

??

?? /*

??? 定義插入一行數(shù)據(jù)所使用的SQL語(yǔ)句，注意最后一行中的問(wèn)號(hào)，它表示需要在插入數(shù)據(jù)

?? 前和具體的值綁定。插入數(shù)據(jù)庫(kù)對(duì)應(yīng)的SQL語(yǔ)句是標(biāo)準(zhǔn)的INSERT命令

?? */

??LOGD("Insert one personal info into personal_info table");

?? #defineINSERT_PERSONAL_INFO? \

??"INSERT INTO personal_info"\

??"(name,age,sex)"\

??"VALUES"\

??"(?,?,?)"?? //注意這一行語(yǔ)句中的問(wèn)號(hào)

??LOGD("\t%s\n",INSERT_PERSONAL_INFO);

?

?? //sqlite3_stmt是SQLite中很重要的一個(gè)結(jié)構(gòu)體，它代表了一條SQL語(yǔ)句

?? sqlite3_stmt* pstmt = NULL;

?? /*

??? 調(diào)用sqlite3_prepare初始化pstmt，并將其和INSERT_PERSONAL_INFO綁定。

??? 也就是說(shuō)，如果執(zhí)行pstmt，就會(huì)執(zhí)行INSERT_PERSONAL_INFO語(yǔ)句

?? */

?? ret =sqlite3_prepare(g_pDBHandle,INSERT_PERSONAL_INFO,-1,&pstmt,NULL);

??CHECK_DB_ERR(ret,SQLITE_OK);

? /*

??? 調(diào)用sqlite3_bind_xxx為該pstmt中對(duì)應(yīng)的問(wèn)號(hào)綁定具體的值，該函數(shù)的第二個(gè)參數(shù)用于

??? 指定第幾個(gè)問(wèn)號(hào)

? */

?? ret =sqlite3_bind_text(pstmt,1,"dengfanping",-1,SQLITE_STATIC);

?? ret =sqlite3_bind_int(pstmt,2,30);

?? ret =sqlite3_bind_text(pstmt,3,"male",-1,SQLITE_STATIC);

?? //調(diào)用sqlite3_step執(zhí)行對(duì)應(yīng)的SQL語(yǔ)句，該函數(shù)如果執(zhí)行成功，我們的personal_info

?? //表中將添加一條新記錄，對(duì)應(yīng)值為（1，dengfanping，30，male）

?? ret =sqlite3_step(pstmt);

??CHECK_DB_ERR(ret,SQLITE_DONE);

?? //調(diào)用sqlite3_finalize銷(xiāo)毀該SQL語(yǔ)句

?? ret =sqlite3_finalize(pstmt);

??

?? //下面將從表中查詢(xún)name為"dengfanping"的person的age值

??LOGD("select dengfanping's age from personal_info table");

?? pstmt =NULL;

?? /*

??? 重新初始化該pstmt，并將其和SQL語(yǔ)句“SELECT age FROM personal_info WHERE name

???? = ?”綁定

?? */

?? ret =sqlite3_prepare(g_pDBHandle,"SELECT age FROM personal_info WHERE name

???????????????????????????????????????????? ?=? ",-1,&pstmt,NULL);

??CHECK_DB_ERR(ret,SQLITE_OK);??

?? /*

??? 綁定pstmt中第一個(gè)問(wèn)號(hào)為字符串“dengfanping”，最終該SQL語(yǔ)句為

??? SELECTage FROM personal_info WHERE name = 'dengfanping'

?? */

?? ret =sqlite3_bind_text(pstmt,1,"dengfanp