Save and retrieve AttributedString to SQLite3 - objective-c

Question

I have a project in Objective-c in which I am trying to find a way of saving the attributedText from a UITextView to a SQLite3 table.
My Project Target OS is 12.1.
I am using an object called "MMItem" with a NSData property called "notesAttributed".
In my viewController Class I am using NSKeyedArchiver to encode the AttributedText into a NSdata format then copying to the object property.
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:self.itemNotes.attributedText requiringSecureCoding:YES error:Nil];
self.item.notesAttributed = data;
I then call a method in my model to save the object
NSString *resultStr = [self.meetingModel saveAttributedItemNote:item];
In the model I'm attempting to save the attributed string to a field in the Item table setup as type 'blob'
- (NSString *)saveAttributedItemNote:(MMItem *)item{
NSString *errorMessage;
NSString *sql;
NSInteger result = 0;
if (item) {
//create blob encoded data for Attributed notes
NSInteger itemID = item.itemID;
sql = [NSString stringWithFormat:
#"UPDATE Item set noteAttributed = %# WHERE itemID = %ld",item.notesAttributed, (long)itemID];
char *err;
// open DB and save
if ([self openDB]){
//NSLog(#"%#", NSStringFromSelector(_cmd));
result = sqlite3_exec(db, [sql UTF8String], NULL, NULL, &err);
sqlite3_close(db);
}
if (result != SQLITE_OK)
{
errorMessage = #"Error";
}
else
{
//NSLog(#"Table updated");
errorMessage = #"OK";
[self saveAttributedItemNote:item];
}
}
item = nil;
return errorMessage;
}
The SQL Execute statement fails with error 1.
I suspect I'm meant to insert the blob into the table using 'binding' and not an Execute statement but I just find how to put this all together using Objective-c.
Any help would be great thanks.

Answer 1

With acknowledgement to the following post iOS SQLite Blob data is saving NULL
I managed to get a working solution. It's apparent that to save a blob into an SQLite you must use a Prepare statement with a sqlite3_bind_blob to insert the blob parameters into the statement, then to use sqlite3_step to deploy it.
This then allows the bytes and length parameters to also be passed into the statement, which I don't think can be done using the execute method I was originally trying.
Here is the code that works perfectly.
- (NSString *)saveAttributedItemNote:(MMItem *)item{
NSString *errorMessage;
if (item) {
//create blob encoded data for Attributed notes
int itemID = (int)item.itemID;
if ([self openDB]) {
const char *insert_stmt = "UPDATE Item set notesAttributed = ? WHERE itemID = ?";
sqlite3_stmt *statement;
if (sqlite3_prepare_v2(db, insert_stmt, -1, &statement, NULL) == SQLITE_OK) {
sqlite3_bind_blob(statement, 1, item.notesAttributed.bytes, (int)item.notesAttributed.length, SQLITE_TRANSIENT);
sqlite3_bind_int(statement, 2, itemID);
if (sqlite3_step(statement) == SQLITE_DONE) {
errorMessage = #"OK";
//update successfull
}else{
const char *err = sqlite3_errmsg(db);
NSString *error = [[NSString alloc] initWithUTF8String:err];
NSLog(#"Update error ID:%#",error);
errorMessage = #"Error";
}
sqlite3_finalize(statement);
}else{
errorMessage = #"Error";
NSLog(#"Unable to prepare stsement %s: %s",insert_stmt, sqlite3_errmsg(db));
}
sqlite3_close(db);
}
}
item = nil;
return errorMessage;
}
The following code then shows how the field was retrieved from sqlite. Column 11 is the blob.
if (sqlite3_prepare(db, [sql UTF8String], -1, &statement, nil)==SQLITE_OK)
{
//NSLog(#"SQL Select OK");
while (sqlite3_step(statement)==SQLITE_ROW) {
MMItem *item = [[MMItem alloc]init];
item.itemID = sqlite3_column_int(statement, 0);
item.topicID = sqlite3_column_int(statement, 1);
item.sequenceID = sqlite3_column_int(statement, 2);
char *description = (char *) sqlite3_column_text(statement, 3);
if(description) item.itemDescription = [[NSString alloc]initWithUTF8String:description];
char *notes = (char *) sqlite3_column_text(statement, 4);
if(notes) item.notes = [[NSString alloc]initWithUTF8String:notes];
char *actionBy = (char *) sqlite3_column_text(statement, 5);
if(actionBy) item.actionBy = [[NSString alloc]initWithUTF8String:actionBy];
char *requiredBy = (char *) sqlite3_column_text(statement, 6);
if (requiredBy) item.requiredBy = [[NSString alloc]initWithUTF8String:requiredBy];
item.completed = sqlite3_column_int(statement, 7);
char *proposedBy = (char *) sqlite3_column_text(statement, 8);
if (proposedBy) item.proposedBy = [[NSString alloc]initWithUTF8String:proposedBy];
char *secondedBy = (char *) sqlite3_column_text(statement, 9);
if (secondedBy) item.secondedBy = [[NSString alloc]initWithUTF8String:secondedBy];
item.carried = sqlite3_column_int(statement, 10);
NSData *attributedTextData = [[NSData alloc]initWithBytes:sqlite3_column_blob(statement,11) length:sqlite3_column_bytes(statement, 11)];
item.notesAttributed = attributedTextData;
[items addObject:item];
item = nil;
}
}
Then in the ViewController, the following was used to take the NSData property and decode this for the UITextView (self.itemNotes)
self.itemNotes.attributedText = [NSKeyedUnarchiver unarchivedObjectOfClass:([NSAttributedString class]) fromData:self.item.notesAttributed error:&error];
Weird how just posting the question lead me to finding the right solution. Thanks to El Tomato for your help bud.