How to add & delete data from SQLite database? - ios

Question

I have tried following the guide on this page SQLite Tutorial? Deleting Data | iPhone SDK Articles but I just can't understand how to implement it in my app, because I the NSMutableArray isn't declared in the AppDelegate as it is in the tutorial
Can someone have a look and guide me through it? I want to be able to delete rows from the tableview and the database and to be able to add data as well.
Here is my app: http://ge.tt/9JNVd89?c
Even the slightest tip will be appreciated.

Answer 1

Will probably need a bit more information as to your current level of knowledge. How far have you gotten? Are you able to connect and read data from it? Do you understand how SQL works?
If you wanted to retrieve data from the db you could write something like the following:
+ (NSArray *)getAllUsers
{
sqlite3 *db = **However you get your db conn**
sqlite3_stmt *statement = nil;
NSMutableArray *userArray = [NSMutableArray array];
NSString *fullQuery = #"SELECT * FROM User";
const char *sql = [fullQuery UTF8String];
if(sqlite3_prepare_v2(db, sql, -1, &statement, NULL)!=SQLITE_OK)
NSAssert1(0, #"Error preparing statement '%s'", sqlite3_errmsg(db));
else
{
while(sqlite3_step(statement) == SQLITE_ROW)
{
User *currentUser = [[User alloc] init];
[User setPk:[NSString stringWithUTF8String:(const char*)sqlite3_column_text(statement, 0)]];
[User setName:[NSString stringWithUTF8String:(const char*)sqlite3_column_text(statement, 1)]];
[User setAge:[NSString stringWithUTF8String:(const char*)sqlite3_column_text(statement, 2)]];
[userArray currentUser];
[currentUser release];
}
}
sqlite3_finalize(statement);
sqlite3_close(db);
return [NSArray arrayWithArray:userArray];
}
and if you wanted to insert data into it:
+ (void)insertUser:(NSString *)username
{
sqlite3 *db = **However you get your db conn**
sqlite3_stmt *statement = nil;
NSString *fullQuery = [NSString stringWithFormat:#"INSERT INTO User (userName) VALUES (%#);", username];
const char *sql = [fullQuery UTF8String];
sqlite3_prepare_v2(db, sql2, -1, &statement, NULL);
if(sqlite3_step(statement) == SQLITE_DONE)
{
NSLog(#"User inserted");
}
sqlite3_finalise(statement);
sqlite3_close(db);
}
If you are having trouble getting a database into your application and connecting to it, let me know and I can post some of that code as well.
Hope that helps :)