Question

- (NSMutableArray*)getEmployeeDetailsByEmployeeName:(int)postid
{
    NSMutableArray *recordSet = [[NSMutableArray alloc]init];

    [self closeanyOpenConnection];


    NSString *fetchQuery = [NSString stringWithFormat:@"select * from SubCategory_Content where SubcategoryID==%d",postid];

    const char *selectQuery = [fetchQuery UTF8String];
    sqlite3_stmt *sqlstatement = nil;

    if (sqlite3_prepare_v2(databaseReference, selectQuery, -1, &sqlstatement , NULL)==SQLITE_OK) {

        NSMutableDictionary *dict = [[NSMutableDictionary alloc]init];

        while (sqlite3_step(sqlstatement) == SQLITE_ROW)
        {
            char* PostIDchar = (char*)sqlite3_column_text(sqlstatement, 1);
            NSString *PostID = [NSString stringWithUTF8String:PostIDchar];
            [dict setValue:PostID forKey:@"PostID"];

            char* ShortContentChar = (char*)sqlite3_column_text(sqlstatement, 2);
            NSString *ShortContentStr = [NSString stringWithUTF8String:ShortContentChar];
            [dict setValue:ShortContentStr forKey:@"ShortContent"];

            char* imageDataFromDatabase = (char*)sqlite3_column_text(sqlstatement, 4);
            NSString *ShortContentImage = [NSString stringWithUTF8String:imageDataFromDatabase];
            [dict setValue:ShortContentImage forKey:@"ShortContentImage"];

            char* titleChar = (char*)sqlite3_column_text(sqlstatement, 5);
            NSString *titlestr = [NSString stringWithUTF8String:titleChar];
            [dict setValue:titlestr forKey:@"Title"];

            [recordSet addObject:dict];

            imageDataFromDatabase = nil;

            dict = nil;

            dict = [[NSMutableDictionary alloc]init];
        }

        dict = nil;
    }

    return  recordSet;
}

Answer 1

如果您还没有了解更多详细信息，我建议您在SubcategoryID列上创建一个索引，这样就可以使用sqlite3_exec调用来执行“创建INDEX idx_SubcategoryID ON SubCategory_Content（SubcategoryID ASC）”。

如果事实上查询是您的问题，您应该会看到性能的显着提升。

如果您只是期望查询得到一个结果，那么肯定会在语句末尾添加“LIMIT 1”，但添加了索引可以减轻这种不足。

您还要求它将大量工作存储和检索图像数据作为文本。如果您可以在应用程序中进行这种更改，我建议将它们存储为BLOB值。

首先，我会在SELECT语句周围设置一些断点，看看这实际上是你的减速，很可能是。

由于

Sqlite数据库花了很长时间才能在iOS中检索数据。显示数据需要5分钟

1 个答案: