如何将核心数据导出到 CSV [英] how to export Core Data to CSV

问题描述

我想使用 CHCSVParser 将我的 Core 数据导出到 CSV.我知道如何从实体中获取所有值，但我不知道如何写入 CSV.

I will like to use CHCSVParser to export my Core data to CSV. I know how to get all the value from entity, but I don't know how to write to CSV.

谁能教我如何使用 CHCSVParser 写入 CSV 文件?

Can anybody teach me how to write to CSV with CHCSVParser?

// Test listing all Infos from the store
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription 
                               entityForName:@"NoteLog" inManagedObjectContext:context];
[fetchRequest setEntity:entity];

NSArray *fetchedObjects = [context executeFetchRequest:fetchRequest error:&error];
for (NoteLog *noteInfo in fetchedObjects) {

    NSLog(@"Name: %@", noteInfo.city );
    NSLog(@"Name: %@", noteInfo.country);
    NSLog(@"Name: %@", noteInfo.datetime);
    NSLog(@"Name: %@", noteInfo.notelatitude);
    NSLog(@"Name: %@", noteInfo.notelongtitude);
    NSLog(@"Name: %@", noteInfo.state);
    NSLog(@"Name: %@", noteInfo.text);        
}  

推荐答案

CHCSVWriter 有几种构造 CSV 文件的方法:

A CHCSVWriter has several methods for constructing CSV files:

-writeField: 接受一个对象并将其 -description(在正确转义后)写入 CSV 文件.如有必要，它还将写入字段分隔符 (,).您可以传递一个空字符串 (@"") 或 nil 来写入一个空字段.

-writeField: accepts an object and writes its -description (after being properly escaped) out to the CSV file. It will also write field seperator (,) if necessary. You may pass an empty string (@"") or nil to write an empty field.

-writeFields: 接受一个以逗号分隔且以 nil 结尾的对象列表，并将每个对象发送到 -writeField:.

-writeFields: accepts a comma-delimited and nil-terminated list of objects and sends each one to -writeField:.

-writeLine 用于终止当前 CSV 行.如果您不调用 -writeLine，则所有 CSV 字段都将位于一行中.

-writeLine is used to terminate the current CSV line. If you do not invoke -writeLine, then all of your CSV fields will be on a single line.

-writeLineOfFields: 接受以逗号分隔且以 nil 结尾的对象列表，将每个对象发送到 -writeField:，然后调用 -writeLine.

-writeLineOfFields: accepts a comma-delimited and nil-terminated list of objects, sends each one to -writeField:, and then invokes -writeLine.

-writeLineWithFields: 接受一组对象，将每个对象发送到 -writeField:，然后调用 -writeLine.

-writeLineWithFields: accepts an array of objects, sends each one to -writeField:, and then invokes -writeLine.

-writeCommentLine: 接受一个字符串并将其作为 CSV 样式的注释写入文件.

-writeCommentLine: accepts a string and writes it out to the file as a CSV-style comment.

除了写入文件之外，CHCSVWriter 还可以初始化为直接写入NSString.

In addition to writing to a file, CHCSVWriter can be initialized for writing directly to an NSString.

这样的东西应该适合你.

Something Like this should work for you.

CHCSVWriter *writer = [[CHCSVWriter alloc] initForWritingToString];

for (NoteLog *noteInfo in fetchedObjects) {

    [writer writeLineOfFields:noteInfo.city, noteInfo.country, noteInfo.datetime, noteInfo.notelatitude, noteInfo.notelongtitude, noteInfo.state, noteInfo.text, nil];     
}  

NSLog(@"My CSV File: %@",writer.stringValue);

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