Encoding problem in sqlite and objective-c

问题

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');

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

NSString *sql = [NSString stringWithContentsOfFile:filename];

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;
}

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');

So then I run it with sqlite3_step(stmt);

At this point, viewing the database reveals this:

1|¬∞ F|Degrees Fahrenheit

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

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

回答1:

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

file contains:

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

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];
}

Then dumping:

% 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;

来源：https://stackoverflow.com/questions/1668774/encoding-problem-in-sqlite-and-objective-c

标签

objective-c

iphone

cocoa

sqlite