Store accented word into Sqlite - iOS - ios

Question

I coulnd not find a solution.
I store data into a local SQLITE DB. Everything works except for accented words.
As in the figure.
However, if I try to store accented word by using SqliteManager (Firefox plugin) everything works. In conclusion: when I store accented word by using my app, strange chars appear.
I use the following code to write data (same for read). Basically, all strings are UTF8 encoded.
-(NSInteger)writeData:(NSDictionary* )data table:(NSString* )table
{
sqlite3_stmt *sqlStatement;
NSMutableArray *columns = [[NSMutableArray alloc] init];
NSMutableArray *values = [[NSMutableArray alloc] init];
NSMutableDictionary *temp = [[NSMutableDictionary alloc] initWithDictionary:data];
#try {
assert([data count] != 0);
if ([[data allKeys] count] == 0) return 1;
[temp removeObjectForKey:#"id"];
[columns addObjectsFromArray:[temp allKeys]];
NSString *cols = [columns componentsJoinedByString:#","];
NSMutableString *colNames = [[NSMutableString alloc] initWithString:
[NSString stringWithFormat:#"INSERT INTO %s (",[table UTF8String]]];
[colNames appendString:cols];
[colNames appendString:#")"];
// VALUES FOR INSERT
[values addObjectsFromArray:[temp allValues] ];
NSMutableString *s = [[NSMutableString alloc] init];
for(int i = 0; i < [values count]; i++)
{
[s setString:[NSString stringWithFormat:#"%#",[values objectAtIndex:i]]];
const char* currentValue = [s UTF8String];
[values setObject:[NSString stringWithFormat:#"\"%s\"",currentValue] atIndexedSubscript:i];
}
NSString *vals = [values componentsJoinedByString:#","];
NSMutableString *valNames = [[NSMutableString alloc] initWithString:#" VALUES ("];
[valNames appendString:vals];
[valNames appendString:#")"];
[colNames appendString:valNames];
const char *sql = [colNames UTF8String];
#ifdef DEBUG
NSLog(#"avvDB writeDATA insert string %#",colNames);
#endif
if(sqlite3_prepare(db, sql, -1, &sqlStatement, NULL) != SQLITE_OK)
{
NSLog(#"Problem with prepare statement write %s",sqlite3_errmsg(db));
return 0;
}
if (sqlite3_exec(db, sql, NULL, NULL, NULL) == SQLITE_OK)
{
// NSLog(#"Last id %llu %s",sqlite3_last_insert_rowid(db),sqlite3_errmsg(db));
}
}// end try
#catch(NSException* e)
{
NSLog(#"Eccezione in write %#",[e reason]);
}
#finally {
sqlite3_reset(sqlStatement);
sqlite3_finalize(sqlStatement);
sqlStatement = nil;
return sqlite3_last_insert_rowid(db);
}
}

Answer 1

The %s operator does not support unicode characters. As the String Format Specifiers of the String Programming Guide says, it is "Null-terminated array of 8-bit unsigned characters."
Frankly, for other reasons, you shouldn't be using stringWithFormat anyway (what if one of the strings had a quotation mark in it ... your SQL statement would fail; you're even exposed to SQL injection attacks). You should be using a ? placeholder instead (with no quotation marks), and then call sqlite3_bind_text for each of the parameters you want to bind to the respective question mark (note, sqlite3_bind_xxx functions use a 1-based index, unlike sqlite3_column_xxx which use a 0-based index).