sqlite和objective-c中的编码问题 [英] Encoding problem in sqlite and objective-c

问题描述

我有一个文件，其内容如下:

I have a file with contents something like this:

INSERT INTO table VALUES (NULL,'° F','Degrees Fahrenheit');
INSERT INTO table VALUES (NULL,'° C','Degrees Celsius');

现在，要解析这个，我有这样的东西:

Now, to parse this, I have something like this:

NSString *sql = [NSString stringWithContentsOfFile:filename];

将此字符串打印到控制台看起来正确.然后，我要用它做一个实际的插入语句:

Printing this string to the console looks correct. Then, I want to make an actual insert statement out of it:

const char *sqlString = [query UTF8String];
const char *endOfString;
if (sqlite3_prepare_v2(db, sqlString + nextStatementStart, -1, &stmt, &endOfString) != SQLITE_OK) {
  return NO;
}

这时，检查查询仍会返回正确的结果.也就是说， sqlite_sql(stmt)返回 INSERT INTO表VALUES(NULL，'°F'，'Degrees Fahrenheit');

At this point, checking the query still returns the correct result. That is, sqlite_sql(stmt) returns INSERT INTO table VALUES (NULL,'° F','Degrees Fahrenheit');

所以我用 sqlite3_step(stmt);

这时，查看数据库将显示以下内容:

At this point, viewing the database reveals this:

1 |¬∞F |表示华氏温度

我不在任何地方使用任何_16函数(例如 sqlite_open16 ).

I'm not using any _16 functions anywhere (like sqlite_open16).

编码问题在哪里?我该如何解决?

Where is the encoding issue? How do I fix this?

推荐答案

stringWithContentsOfFile:从OSX 10.4开始不推荐使用(不确定iPhone)，但是您想在此处使用 stringWithContentsOfFile:encoding:error

stringWithContentsOfFile: is deprecated as of OSX 10.4 (not sure about iPhone), but you want to specify the encoding here using stringWithContentsOfFile:encoding:error

文件包含:

CREATE TABLE myvalues (foo TEXT, bar TEXT, baz TEXT);
INSERT INTO myvalues VALUES (NULL,'° F','Degrees Fahrenheit');

test.m包含(未提供错误处理):

test.m contains (no error handling provided):

int main(int argc, char** argv)
{
    NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];

    NSString* s = [NSString stringWithContentsOfFile:@"file"
                            encoding:NSUTF8StringEncoding
                        error:nil];
    NSLog(@"s: %@", s);

    sqlite3* handle;
    sqlite3_open("file.db", &handle);
    sqlite3_exec(handle, [s UTF8String], NULL, NULL, NULL);
    sqlite3_close(handle);

    [pool release];
}

然后转储:

% sqlite3 file.db
SQLite version 3.6.12
Enter ".help" for instructions
Enter SQL statements terminated with a ";"
sqlite> .dump
BEGIN TRANSACTION;
CREATE TABLE myvalues (foo TEXT, bar TEXT, baz TEXT);
INSERT INTO "myvalues" VALUES(NULL,'° F','Degrees Fahrenheit');
COMMIT;

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