sqlite3_iphone
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1. 预备知识 读者需要有一定的SQLite数据库知识，懂得基本的SQL语句，掌握OSX系统terminal终端 以及 XCode编译器 的基本操作。 2. 创建数据库 打开 Applications-Utilities-Terminal，可见终端窗口。 假设当前系统用户为Smitty，可在终端窗口内键入如下命令： cd /Users/Smitty/Documents mkdir SQLiteDemo cd SQLiteDemo sqlite3 PersonDatabase.sql 至此，你已经在/Users/lookaflyingdonkey/Documents目录下创建了一个新的目录SQLiteDemo，并使用 sqlite3命令开启了SQLite终端，准备建立数据库结构并输入数据。 举例来说，若我们要建立的数据库表person需要有如下结构：唯一的id值，名字，职位描述，头像图片地址，那么下列命令将创建这个表，并添加几个人的纪录。 CREATE TABLE person (id INTEGER PRIMARY KEY,name VARCHAR(50),title TEXT,icon VARCHAR(255) ); INSERT INTO person (name,title,icon) VALUES('Peter','handy man','http://dblog.com.au/wp-content/elephant.jpg'); INSERT INTO person (name,icon) VALUES('Susan','manager','http://dblog.com.au/wp-content/monkey.jpg'); INSERT INTO person (name,icon) VALUES('Wilson','developer','http://dblog.com.au/wp-content/kangaroo.jpg'); 执行完这几步后，可运行命令"SELECT * FROM person;"，检查数据库中是否已存在上面插入的数据。一旦确认一切正常，可用命令".quit"退出sqlite 命令行模式。 3. 创建项目 现在让我门创建Xcode项目。 首先在Xcode中选择创建一个新的” Navigation-Based Application“ 输入项目名称"SQLiteDemo"，由于之前在同一位置创建了同名目录，Xcode将会询问是否覆盖已经存在的目录SQLiteDemo，选则是。这将使项目目录结构如下图所示。 4. 将SQLite框架和PersonDatabas数据库导入项目 首先我们需要将SQLite库引入项目。请右键点击左部菜单中的"Frameworks"目录，选择“Add > Existing Frameworks…”， 然后在本地目录中选择“/Developer/Platforms/iPhoneOS.platform/Developer /SDKs/iPhoneOS3.0.sdk/usr/lib/”，找到“libsqlite3.0.dylib”文件并双击。 一个弹出窗口将出现，点击其中“Add”按钮将库添加入项目中。
我们也需要将PersonDatabas 数据库导入Resources目录。请右键点击“Resources”目录，选择“Add > Existing Files…”，在本地目录中选择“/Users/Smitty/Documents/SQLiteDemo/”,双击PersonDatabase.sql文件，点击弹出窗口中的“Add”按钮将其导入当前项目。 5. 开始编程 首先创建一个Person类。右键点击“Classes”目录，选择“Add > New File…”，在弹出窗口中选择“iPhone OS > Cocoa Touch Class > Objective-C class > NSObject” 并点击“Next”按钮。在下一窗口中，设置File Name为“Person.m”。点击“Finish”按钮完成创建。 修改Classes/Person.h为： @interface Person : NSObject { NSString *name; NSString *title; NSString *iconURL; } @property (nonatomic,retain) NSString *name; @property (nonatomic,retain) NSString *title; @property (nonatomic,retain) NSString *iconURL; -(id)initWithName:(NSString *)n title:(NSString *)t url:(NSString *)u; @end 修改Classes/Person.m为： #import "Person.h" @implementation Person @synthesize name,iconURL; -(id)initWithName:(NSString *)n title:(NSString *)t url:(NSString *)u { self.name=n; self.title=t; self.iconURL=u; return self; } @end 修改Other Sources/main.m为： #import #import "Person.h" int main(int argc,char *argv[]) { NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; //setup database name. NSString *databaseName = @"PersonDatabase.sql"; // Get the path to the documents directory and append the databaseName NSArray *documentPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES); NSString *documentsDir = [documentPaths objectAtIndex:0]; NSString *databasePath = [documentsDirstringByAppendingPathComponent:databaseName];
// Create a FileManager object,we will use this to check the status // of the database and to copy it over if required NSFileManager *fileManager = [NSFileManager defaultManager]; // Check if the database has already been created in the users filesystem BOOL success = [fileManager fileExistsAtPath:databasePath]; // If the database already exists then return without doing anything if(!success){ // If not then proceed to copy the database from the application to the users filesystem // Get the path to the database in the application package NSString *databasePathFromApp = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:databaseName]; // Copy the database from the package to the users filesystem [fileManager copyItemAtPath:databasePathFromApp toPath:databasePath error:nil]; } // Query the database for all person records and construct the "person" array sqlite3 *database; // Init the animals Array NSMutableArray *personArr = [[NSMutableArray alloc] init]; // Open the database from the users filessytem if(sqlite3_open([databasePath UTF8String],&database) == SQLITE_OK) { // Setup the SQL Statement and compile it for faster access const char *sqlStatement = "select * from person"; sqlite3_stmt *compiledStatement; if(sqlite3_prepare_v2(database,sqlStatement,-1,&compiledStatement,NULL) == SQLITE_OK) { // Loop through the results and add them to the feeds array while(sqlite3_step(compiledStatement) == SQLITE_ROW) { // Read the data from the result row NSString *aName = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement,1)]; NSString *aTitle = [NSString stringWithUTF8String:(char*)sqlite3_column_text(compiledStatement,2)];
NSString *aIconUrl = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement,3)]; // Create a new animal object with the data from the database Person *person = [[Person alloc] initWithName:aName title:aTitle url:aIconUrl]; // Add the animal object to the animals Array [personArr addObject:person]; [person release]; } } // Release the compiled statement from memory sqlite3_finalize(compiledStatement); } sqlite3_close(database); for (Person *tmpPerson in personArr) { NSLog(@"You can see %@ %@'s icon at %@",tmpPerson.title,tmpPerson.name,tmpPerson.iconURL); [tmpPerson release]; } NSLog(@"Done."); [personArr release]; [fileManager release]; [pool release]; return (0); } 6. 编译执行 完成修改后，运行“Build > Build and Run”,关掉弹出的iPhone Simulator窗口，选择"Run > Console" 打开控制台，可看到如下输出信息。 参考： http://www.cnblogs.com/AlexLiu/archive/2010/04/21/1716740.html （编辑：李大同） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |