在iPhone中涉及数据库的操作的时候,在更新操作中要传递可变参数,这些可变参数其实就是数据库语句,这样在数据库涉及的过程中,不利于数据和业务的分离,对此,我们可以对其提供的函数再包装。
首先来看看Object C中对可变参数函数的定义、调用,eg:
1 .h文件
2
3 @interface sqlHelper : NSObject
4
5 {
6
7 }
8
9 -(int) executeInsertWithSql:(NSString *) statement, ...;
10
11 @end
12
13 .m文件
14
15 -(int) executeInsertWithSql:(NSString *) statement, ...
16 {
17 PLSqliteDatabase* dbPointer = [SqliteDataBase setUp];
18
19 argsArray = [[NSMutableArray alloc] init];
20 id arg;
21 va_list argList;
22 if(statement)
23 {
24 va_start(argList,statement);
25 while (arg = va_arg(argList,id))
26 {
27 [argsArray addObject:arg];
28 }
29 va_end(argList);
30 }
31
32 BOOL bResult = [dbPointer executeUpdate:statement,[argsArray objectAtIndex:0],[argsArray objectAtIndex:1]];
33
34 return bResult;
35 }
2
3 @interface sqlHelper : NSObject
4
5 {
6
7 }
8
9 -(int) executeInsertWithSql:(NSString *) statement, ...;
10
11 @end
12
13 .m文件
14
15 -(int) executeInsertWithSql:(NSString *) statement, ...
16 {
17 PLSqliteDatabase* dbPointer = [SqliteDataBase setUp];
18
19 argsArray = [[NSMutableArray alloc] init];
20 id arg;
21 va_list argList;
22 if(statement)
23 {
24 va_start(argList,statement);
25 while (arg = va_arg(argList,id))
26 {
27 [argsArray addObject:arg];
28 }
29 va_end(argList);
30 }
31
32 BOOL bResult = [dbPointer executeUpdate:statement,[argsArray objectAtIndex:0],[argsArray objectAtIndex:1]];
33
34 return bResult;
35 }