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数据加载中……

IOS下SQLite的简单使用

看着国外网站的教程,写了一个小例子,一个联系人的程序,包括 (姓名、地址、电话)三项内容,通过两个按钮,可以将信息保存或者查询数据库已有的信息。

UI就不说了,比较简单。贴一下关键代码,具体的话还是去看源代码(正想办法传,我这git出点问题)。

 

/*根据路径创建数据库并创建一个表contact(id nametext addresstext phonetext)*/

- (void)viewDidLoad

{

[super viewDidLoad];

// Do any additional setup after loading the view, typically from a nib.

 

NSString *docsDir;

NSArray *dirPaths;

 

// Get the documents directory

dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

 

docsDir = [dirPaths objectAtIndex:0];

 

// Build the path to the database file

databasePath = [[NSString alloc] initWithString: [docsDir stringByAppendingPathComponent: @"contacts.db"]];

 

NSFileManager *filemgr = [NSFileManager defaultManager];

 

if ([filemgr fileExistsAtPath:databasePath] == NO)

{

const char *dbpath = [databasePath UTF8String];

if (sqlite3_open(dbpath, &contactDB)==SQLITE_OK)

{

char *errMsg;

const char *sql_stmt = "CREATE TABLE IF NOT EXISTS CONTACTS(ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT, ADDRESS TEXT,PHONE TEXT)";

if (sqlite3_exec(contactDB, sql_stmt, NULL, NULL, &errMsg)!=SQLITE_OK)

{

status.text = @"创建表失败\n";

}

}

else

{

status.text = @"创建/打开数据库失败";

}

}

 

}

 

/*将数据保存只数据库,当按下保存按钮的时候*/

 

- (IBAction)SaveToDataBase:(id)sender

{

sqlite3_stmt *statement;

 

const char *dbpath = [databasePath UTF8String];

 

if (sqlite3_open(dbpath, &contactDB)==SQLITE_OK) {

NSString *insertSQL = [NSString stringWithFormat:@"INSERT INTO CONTACTS (name,address,phone) VALUES(\"%@\",\"%@\",\"%@\")",name.text,address.text,phone.text];

const char *insert_stmt = [insertSQL UTF8String];

sqlite3_prepare_v2(contactDB, insert_stmt, -1, &statement, NULL);

if (sqlite3_step(statement)==SQLITE_DONE) {

status.text = @"已存储到数据库";

name.text = @"";

address.text = @"";

phone.text = @"";

}

else

{

status.text = @"保存失败";

}

sqlite3_finalize(statement);

sqlite3_close(contactDB);

}

}

 

/*根据输入的姓名来查询数据*/

- (IBAction)SearchFromDataBase:(id)sender

{

const char *dbpath = [databasePath UTF8String];

sqlite3_stmt *statement;

 

if (sqlite3_open(dbpath, &contactDB) == SQLITE_OK)

{

NSString *querySQL = [NSString stringWithFormat:@"SELECT address,phone from contacts where name=\"%@\"",name.text];

const char *query_stmt = [querySQL UTF8String];

if (sqlite3_prepare_v2(contactDB, query_stmt, -1, &statement, NULL) == SQLITE_OK)

{

if (sqlite3_step(statement) == SQLITE_ROW)

{

NSString *addressField = [[NSString alloc] initWithUTF8String:(const char *)sqlite3_column_text(statement, 0)];

address.text = addressField;

 

NSString *phoneField = [[NSString alloc] initWithUTF8String:(const char *)sqlite3_column_text(statement, 1    )];

phone.text = phoneField;

 

status.text = @"已查到结果";

[addressField release];

[phoneField release];

}

else {

status.text = @"未查到结果";

address.text = @"";

phone.text = @"";

}

sqlite3_finalize(statement);

}

 

sqlite3_close(contactDB);

}

}

posted on 2012-05-31 23:37 Wangkeke 阅读(1234) 评论(0)  编辑 收藏 引用 所属分类: IOS


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