IOS下SQLite的簡單使用

看着國外網站的教程，寫了一個小例子，一個聯系人的程序，包括 （姓名、地址、電話）三項內容，通過兩個按鈕，可以將信息保存或者查詢數據庫已有的信息。

UI就不說了，比較簡單。貼一下關鍵代碼，具體的話還是去看源代碼(正想辦法傳，我這git出點問題)。

 git:https://github.com/cokecoffe/ios-demo/tree/master/SQLite%E7%9A%84%E5%9F%BA%E6%9C%AC%E4%BD%BF%E7%94%A8

/*根據路徑創建數據庫並創建一個表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 = @"創建表失敗\n";
            }
        }
        else
        {
            status.text = @"創建/打開數據庫失敗";
        }
    }
    
}

/*將數據保存只數據庫，當按下保存按鈕的時候*/

- (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 = @"已存儲到數據庫";
            name.text = @"";
            address.text = @"";
            phone.text = @"";
        }
        else
        {
            status.text = @"保存失敗";
        }
        sqlite3_finalize(statement);
        sqlite3_close(contactDB);
    }
}

/*根據輸入的姓名來查詢數據*/
- (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 = @"已查到結果";
                [addressField release];
                [phoneField release];
            }
            else {
                status.text = @"未查到結果";
                address.text = @"";
                phone.text = @"";
            }
            sqlite3_finalize(statement);
        }
        
        sqlite3_close(contactDB);
    }
}

 

 

Wangkeke 2012-05-31 23:37 發表評論