problem while loading data stored in data base into table view - iphone

Question

hii every one
i am using following code to loading data stored in data base into table view but its crasing when i re-launch the application
InsertRecord is the instance of class insertUpdateDelete
+ (void) getInitialDataToDisplay:(NSString *)dbPath
{
iICS_testAppDelegate *appDelegate = (iICS_testAppDelegate *)[[UIApplication sharedApplication] delegate];
if (sqlite3_open([dbPath UTF8String], &database) == SQLITE_OK) {
const char *sql = "select * from tbl_Users";
sqlite3_stmt *selectstmt;
if(sqlite3_prepare_v2(database, sql, -1, &selectstmt, NULL) == SQLITE_OK) {
while(sqlite3_step(selectstmt) == SQLITE_ROW) {
NSInteger primaryKey = sqlite3_column_int(selectstmt, 0);
insertUpdateDelete *InsertRecord = [[insertUpdateDelete alloc] initWithPrimaryKey:primaryKey];
InsertRecord.strFirstName = [NSString stringWithUTF8String:(char *)sqlite3_column_text(selectstmt, 1)];
InsertRecord.strMiddleName = [NSString stringWithUTF8String:(char *)sqlite3_column_text(selectstmt, 2)];
[appDelegate.arrObjects addObject:InsertRecord];
[InsertRecord release];
}
}
}
else
{
sqlite3_close(database); //Even though the open call failed, close the database connection to release all the memory.
}
NSLog(#"arrObjects----%#",appDelegate.arrObjects);
}
application is crashing at the following line
InsertRecord.strFirstName = [NSString stringWithUTF8String:(char *)sqlite3_column_text(selectstmt, 1)];
crash log is-- Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '* +[NSString stringWithUTF8String:]: NULL cString'

Answer 1

You need to check for null data in your database;
// load char in temporary variable
char *tempChar = sqlite3_column_text(selectstmt, 1);
if(tempChar == null) // test for null
InsertRecord.strFirstName = nil;
else
InsertRecord.strFirstName = [NSString stringWithUTF8String:tempChar];
// go to the next field in the database
tempChar = sqlite3_column_text(selectstmt, 2);
// do the same type of test

Answer 2

Test if the sqlite3_column_text(selectstmt, 1) return an valid string.

Answer 3

(char *)sqlite3_column_text(selectstmt, 1) should be given nil (null) value.
So, Add validation when you get data from database.
Like,
if ((char *)sqlite3_column_text(selectstmt, 1) != nil)
{
InsertRecord.strFirstName = [NSString stringWithUTF8String:(char *)sqlite3_column_text(selectstmt, 1)];
}
else
{
InsertRecord.strFirstName = #"";
}