Sqlite Database locked in some case while inserting data - ios

Question

I have a problem in my Iphone application.
Some time my Application run successfully,But in some cases it give "databse is locked exception"thats why i am unable to read or insert data from sqlite datase.
Please suggest me if any one have some solution.
This is my code of inserting data into databse
Thanks.
-(void)insertDataIntoDatabase
{
NSLog(#"insertDataIntoDatabase-----1");
#try{
tUserName=userNameTf.text;
tLevel=[NSString stringWithFormat:#"%d",level];
tMoves=[NSString stringWithFormat:#"%d",moves];
NSLog(#"tLevel;;;%#",tLevel);
// NSString *tdatabaseName = #"FlipScoreBord.sqlite";
sqlite3_stmt *addStatement;
// NSArray *tdocumentPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
// NSString *tdocumentsDir = [tdocumentPaths objectAtIndex:0];
// NSString *tdatabasePath = [tdocumentsDir stringByAppendingPathComponent:tdatabaseName];
NSString *insertQuery = [NSString stringWithFormat:#"INSERT INTO Moves (User_Name,User_Label,User_Moves) VALUES('%#','%#','%#')",tUserName,tLevel,tMoves];
const char *sql = [insertQuery cStringUsingEncoding:NSUTF8StringEncoding];
if(sqlite3_prepare_v2(tdatabase, sql, -1, &addStatement, NULL) != SQLITE_OK)
{
NSAssert1(0, #"Error while creating add statement. '%s'", sqlite3_errmsg(tdatabase));
}
sqlite3_bind_text(addStatement, 0, [tUserName UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(addStatement, 1, [tLevel UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(addStatement, 2, [tUserName UTF8String], -1, SQLITE_TRANSIENT);
if(SQLITE_DONE != sqlite3_step(addStatement))
{
NSAssert1(0, #"Error while inserting data. '%s'", sqlite3_errmsg(tdatabase));
sqlite3_reset(addStatement);
}
sqlite3_close(tdatabase);
}
#catch (NSException *r)
{
NSLog(#"Exception---- %#",r);
}
NSLog(#"insertDataIntoDatabase-----2");
}

Answer 1

I have to confess that I use FMDB (a SQLite wrapper that insulates me from the SQLite functions), but a couple of things look odd:
If you sqlite3_prepare_v2() a statement, don't you need your sqlite3_finalize()?
It looks like you're closing the db here, but not opening it. Seems like that opens the possibility that your sqlite3_open() statements and your sqlite3_close() calls are not balanced. Are you 100% confident that this is not the problem? I'd try putting in NSLog's at the open and close statements and make sure they're balanced.
The combination these two issues make me wonder if you meant sqlite3_finalize() where you currently have sqlite3_close().
Just a few ideas.

Answer 2

This link lists the reasons how a database lock error can be triggered:
http://www.sqlite.org/cvstrac/wiki?p=DatabaseIsLocked
Quoting one of the reasons:
Trying to write to a table while a SELECT is active on that same table.
Since you did not call the sqlite3_finalize on your statement, it is possible that a previous 'SELECT' statement is blocking your 'INSERT'. Try adding an sqlite3_finalize before you call the sqlite3_close.