SqlLite Not execute query Some time - iphone

Question

I have Sequence of Queries that need to be performed with database..
Most of time its working fine.. but some time it failed to insert query.
if (sqlite3_open(dbpath, &contactDB) == SQLITE_OK)
{
for (int i=0;i<[queries count]; i++)
{
NSString *query = [queries objectAtIndex:i];
const char *Insert_query = [query UTF8String];
sqlite3_prepare(contactDB, Insert_query, -1, &statement, NULL);
if (sqlite3_step(statement) == SQLITE_DONE)
{
//NSLog(#" \n\n\n\n %# done query",query);
}
else {
NSLog(#" \n\n\n\n %# not done query",query);
}
}
sqlite3_finalize(statement);
sqlite3_close(contactDB);
}
Above is code which i have implemented to perform insert operation...
Can any one help me to find if it fails then for what reason it failed to insert to database so i can handle error..

Answer 1

Use this method to execute query on sqlite
//-----------------------------------------------------------------------------------------------------//
#pragma mark - Helper methods
//-----------------------------------------------------------------------------------------------------//
-(BOOL)dbOpenedSuccessfully
{
if(sqlite3_open([[self dbPath] UTF8String], &_database) == SQLITE_OK)
{
return YES;
}
else
{
[[[UIAlertView alloc]initWithTitle:#"Error"
message:#"Error on opening the DB"
delegate:self
cancelButtonTitle:#"OK"
otherButtonTitles:nil, nil]show];
return NO;
}
}
//-----------------------------------------------------------------------------------------------------//
#pragma mark - Query
//-----------------------------------------------------------------------------------------------------//
- (void) executeQuery:(NSString *)strQuery
{
char *error = NULL;
if([self dbOpenedSuccessfully])
{
NSLog(#"%#",strQuery);
sqlite3_exec(_database, [strQuery UTF8String], NULL, NULL,&error);
if (error!=nil) {
NSLog(#"%s",error);
}
sqlite3_close(_database);
}
}
Also If insert not works properly the reason may be the file is not in the documents directory and if it is there in bundle it will fetch tha data but cannot update or insert value if db is in bundle ,Copy it to the documents directory and then try using it
-(void) checkAndCreateDatabase
{
// Check if the SQL database has already been saved to the users phone, if not then copy it over
BOOL success;
// Create a FileManager object, we will use this to check the status
// of the database and to copy it over if required
NSFileManager *fileManager = [NSFileManager defaultManager];
// Check if the database has already been created in the users filesystem
success = [fileManager fileExistsAtPath:_databasePath];
// If the database already exists then return without doing anything
if(success) return;
// If not then proceed to copy the database from the application to the users filesystem
// Get the path to the database in the application package
NSString *databasePathFromApp = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:_databaseName];
// Copy the database from the package to the users filesystem
[fileManager copyItemAtPath:databasePathFromApp toPath:_databasePath error:nil];
}
For more info see this

Answer 2

You can try printing the error in the following way, Based on the error you can make decision.
if (sqlite3_open(dbpath, &contactDB) == SQLITE_OK)
{
for (int i=0;i<[queries count]; i++)
{
NSString *query = [queries objectAtIndex:i];
const char *Insert_query = [query UTF8String];
sqlite3_prepare(contactDB, Insert_query, -1, &statement, NULL);
if (sqlite3_step(statement) == SQLITE_DONE)
{
//NSLog(#" \n\n\n\n %# done query",query);
}
else {
NSLog(#"sqlite3_step error: '%s'", sqlite3_errcode(contactDB));
NSLog(#" \n\n\n\n %# not done query",query);
}
}
sqlite3_finalize(statement);
sqlite3_close(contactDB);
}
Additionally,
SQLITE_DONE means that the statement has finished executing
successfully. sqlite3_step() should not be called again on this
virtual machine without first calling sqlite3_reset() to reset the
virtual machine back to its initial state.
You can use, SQLITE_OK instead of SQLITE_DONE.