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)。
1 /*根据路径创建数据库并创建一个表contact(id nametext addresstext phonetext)*/ 2 3 - (void)viewDidLoad 4 { 5 [super viewDidLoad]; 6 // Do any additional setup after loading the view, typically from a nib. 7 8 NSString *docsDir; 9 NSArray *dirPaths; 10 11 // Get the documents directory 12 dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 13 14 docsDir = [dirPaths objectAtIndex:0]; 15 16 // Build the path to the database file 17 databasePath = [[NSString alloc] initWithString: [docsDir stringByAppendingPathComponent: @"contacts.db"]]; 18 19 NSFileManager *filemgr = [NSFileManager defaultManager]; 20 21 if ([filemgr fileExistsAtPath:databasePath] == NO) 22 { 23 const char *dbpath = [databasePath UTF8String]; 24 if (sqlite3_open(dbpath, &contactDB)==SQLITE_OK) 25 { 26 char *errMsg; 27 const char *sql_stmt = "CREATE TABLE IF NOT EXISTS CONTACTS(ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT, ADDRESS TEXT,PHONE TEXT)"; 28 if (sqlite3_exec(contactDB, sql_stmt, NULL, NULL, &errMsg)!=SQLITE_OK) 29 { 30 status.text = @"创建表失败\n"; 31 } 32 } 33 else 34 { 35 status.text = @"创建/打开数据库失败"; 36 } 37 } 38 39 } 40 41 /*将数据保存只数据库,当按下保存按钮的时候*/ 42 43 - (IBAction)SaveToDataBase:(id)sender 44 { 45 sqlite3_stmt *statement; 46 47 const char *dbpath = [databasePath UTF8String]; 48 49 if (sqlite3_open(dbpath, &contactDB)==SQLITE_OK) { 50 NSString *insertSQL = [NSString stringWithFormat:@"INSERT INTO CONTACTS (name,address,phone) VALUES(\"%@\",\"%@\",\"%@\")",name.text,address.text,phone.text]; 51 const char *insert_stmt = [insertSQL UTF8String]; 52 sqlite3_prepare_v2(contactDB, insert_stmt, -1, &statement, NULL); 53 if (sqlite3_step(statement)==SQLITE_DONE) { 54 status.text = @"已存储到数据库"; 55 name.text = @""; 56 address.text = @""; 57 phone.text = @""; 58 } 59 else 60 { 61 status.text = @"保存失败"; 62 } 63 sqlite3_finalize(statement); 64 sqlite3_close(contactDB); 65 } 66 } 67 68 /*根据输入的姓名来查询数据*/ 69 - (IBAction)SearchFromDataBase:(id)sender 70 { 71 const char *dbpath = [databasePath UTF8String]; 72 sqlite3_stmt *statement; 73 74 if (sqlite3_open(dbpath, &contactDB) == SQLITE_OK) 75 { 76 NSString *querySQL = [NSString stringWithFormat:@"SELECT address,phone from contacts where name=\"%@\"",name.text]; 77 const char *query_stmt = [querySQL UTF8String]; 78 if (sqlite3_prepare_v2(contactDB, query_stmt, -1, &statement, NULL) == SQLITE_OK) 79 { 80 if (sqlite3_step(statement) == SQLITE_ROW) 81 { 82 NSString *addressField = [[NSString alloc] initWithUTF8String:(const char *)sqlite3_column_text(statement, 0)]; 83 address.text = addressField; 84 85 NSString *phoneField = [[NSString alloc] initWithUTF8String:(const char *)sqlite3_column_text(statement, 1 )]; 86 phone.text = phoneField; 87 88 status.text = @"已查到结果"; 89 [addressField release]; 90 [phoneField release]; 91 } 92 else { 93 status.text = @"未查到结果"; 94 address.text = @""; 95 phone.text = @""; 96 } 97 sqlite3_finalize(statement); 98 } 99 100 sqlite3_close(contactDB); 101 } 102 }
posted on 2012-05-31 23:37 cokecoffe 阅读(9449) 评论(0) 编辑 收藏 举报