Nesting of Sql Statements - ios

Question

Hi i have made a function in my app delegate to remove the redundancy of my database , I am not sure do i have coded right as i have to perform nesting of SQL statements to find out the error in DB.
Can any body suggest me where i am wrong because the application is running well in simulator and crashing in Device.
I am even Not Sure where to Put finalize and sqlite3_close . Kindly help
-(void) removeRedundancy2
{
NSArray *docPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
dbPathString = [[docPaths objectAtIndex:0] stringByAppendingPathComponent:#"turfnutritiontool_ver_99.db"];
sqlite3_stmt *selectStmt;
sqlite3_stmt *selectStmt1;
BOOL isMyFileThere = [[NSFileManager defaultManager] fileExistsAtPath:dbPathString];
if (isMyFileThere)
{
if (sqlite3_open([dbPathString UTF8String], &database1)==SQLITE_OK)
{
// TO REMOVE FROM from tnt_scenario_product when NO ProductID Found
NSString *querySql2= [NSString stringWithFormat:#"SELECT productid from tnt_scenarioproduct"];
const char* query_sql2 = [querySql2 UTF8String];
if(sqlite3_prepare_v2(database1, query_sql2, -1, &selectStmt, NULL) == SQLITE_OK)
{
while (sqlite3_step(selectStmt) == SQLITE_ROW)
{
int productid = sqlite3_column_int(selectStmt, 0);
// NSLog(#"ProductId1 =%d",productid);
NSString *querySql21= [NSString stringWithFormat:#"SELECT productid from tnt_productcontent WHERE productid = %d",productid];
const char* query_sql21 = [querySql21 UTF8String];
if(sqlite3_prepare_v2(database1, query_sql21, -1, &selectStmt1, NULL) == SQLITE_OK)
{
if (sqlite3_step(selectStmt1) == SQLITE_ROW)
{
// DO NOTHING
}
else
{ // to delete scenario without product id
NSLog(#"Delete this Product from TPC 2 %d",productid);
NSString *querydelete2= [NSString stringWithFormat:#"DELETE from tnt_scenarioproduct WHERE productid = %d",productid];
const char* query_delete2 = [querydelete2 UTF8String];
char *error;
sqlite3_exec(database1, query_delete2, NULL, NULL, &error);
NSLog(#"error=%s ",error);
sqlite3_finalize(selectStmt1);
}
}
sqlite3_finalize(selectStmt1);
sqlite3_close(database1);
}
sqlite3_finalize(selectStmt);
}
sqlite3_close(database1);
}
sqlite3_close(database1);
}
}

Answer 1

After calling sqlite3_open, you must call sqlite3_close for that connection exactly once.
After calling sqlite3_prepare_v2, you must call sqlite3_finalize for that statement exactly once.
if (sqlite3_open([dbPathString UTF8String], &database1)==SQLITE_OK)
{
...
if(sqlite3_prepare_v2(database1, query_sql21, -1, &selectStmt1, NULL) == SQLITE_OK)
{
...
}
sqlite3_finalize(selectStmt);
....
}
sqlite3_close(database1);
Furthermore, you should not reuse the same variable (selectStmt) for two different queries to prevent confusion about its lifetime.