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 }