ios sqlite

@synthesize db;
@synthesize dbName;

-(void)openAndCreate
{
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentDirectory = [paths objectAtIndex:0];
    NSString *dbPath = [documentDirectory stringByAppendingPathComponent:@"test.db"];
    db = [FMDatabase databaseWithPath:dbPath];
    if(![db open])
    {
        NSLog(@"不能打开sqlite");
    }
}
-(void)openDatabase
{
       [db setShouldCacheStatements:YES];
}
-(void)createTable
{
    [db executeUpdate:@"CREATE TABLE User (Name text,Age integer)"];
}
-(void)insertTable
{
    [db executeUpdate:@"INSERT INTO User (Name,Age) VALUES (?,?)",@"李四",[NSNumber numberWithInt:20]];
}
-(void)showTable
{
    FMResultSet *rs=[db executeQuery:@"SELECT * FROM User"];
    //NSString *aa=[db stringForQuery:@"SELECT Name FROM User WHERE Age = ?",@"20"];
    rs=[db executeQuery:@"SELECT * FROM User WHERE Age = ?",@"20"];
    while ([rs next]){
        NSLog(@"%@ %@",[rs stringForColumn:@"Name"],[rs stringForColumn:@"Age"]);
    }
    [rs close]; 
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    [self openAndCreate]; //创建数据库要慎重，创建前要判断是否已有该名字的数据库？貌似没有覆盖啊？再查查
    //[self createTable];
    //[self insertTable];
    
    [self showTable];
    // Do any additional setup after loading the view, typically from a nib.
    
}