Question

I’m having an issue where I execute my app, I get the following warning:
“Incompatible pointer types passing ‘const char *’ to parameter of type ‘sqlite3_stmt *’ (aka ‘struct sqlite3_stmt *’)”.

It only happens on the following lines:

if (sqlite3_prepare_v2(database, sql, -1, &databasePath, NULL)!=SQLITE_OK)

while (sqlite3_step(sql) == SQLITE_ROW)

szStore = [NSString stringWithUTF8String:(char*)sqlite3_column_text(sql, 0)];

szReg = [NSString stringWithUTF8String:(char*)sqlite3_column_text(sql, 1)];

sqlite3_finalize(sql); 

Here is the function:

-(IBAction)setInput:(id)sender
{
NSString *strStoreNumber;
NSString *strRegNumber;

strStoreNumber = StoreNumber.text;
strRegNumber = RegNumber.text;
lblStoreNumber.text = strStoreNumber;
lblRegNumber.text = strRegNumber;

NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,         NSUserDomainMask, YES);
NSString* documentsDirectory = [paths lastObject];
//    NSString* databasePath = [documentsDirectory   stringByAppendingPathComponent:@"tblStore.sqlite"];
NSString* databasePath = [[NSBundle mainBundle] pathForResource:@"tblStore" ofType:@"sqlite"];

if(sqlite3_open([databasePath UTF8String], &database) == SQLITE_OK) 
{

NSLog(@"Opened sqlite database at %@", databasePath);

//...stuff
} 
else 
{
NSLog(@"Failed to open database at %@ with error %s", databasePath,     sqlite3_errmsg(database));
sqlite3_close (database);
}

NSString *querystring;

// create your statement
querystring = [NSString stringWithFormat:@"SELECT strStore FROM tblStore WHERE strStore = %@;", strStoreNumber];  

const char *sql = [querystring UTF8String];

NSString *szStore = nil;
NSString *szReg = nil;


if (sqlite3_prepare_v2(database, sql, -1, &databasePath, NULL)!=SQLITE_OK) //queryString =    Statement
{
NSLog(@"sql problem occured with: %s", sql);
NSLog(@"%s", sqlite3_errmsg(database));
}
else
{
// you could handle multiple rows here

while (sqlite3_step(databasePath) == SQLITE_ROW) // queryString = statement
{            
    szStore = [NSString stringWithUTF8String:(char*)sqlite3_column_text(databasePath, 0)];
    szReg = [NSString stringWithUTF8String:(char*)sqlite3_column_text(databasePath, 1)];
} // while        

}

sqlite3_finalize(databasePath);

// Do something with data...  
}

Any help or insight would be greatly appreciated. Thanks!

Answer 1

The database path is passed instead a statement handle pointer. Replace

if (sqlite3_prepare_v2(database, sql, -1, &databasePath, NULL)!=SQLITE_OK)

with

sqlite3_stmt *statement = nil;
if (sqlite3_prepare_v2(database, sql, -1, &statement, NULL)!=SQLITE_OK)

and set the finalization line to

sqlite3_finalize(statement);

The documentation on sqlite3_prepare_v2 gives more details on this method.