Database is locked error in sqlite

Question

I am using sqlite database for store my data.But it is showing error of "database is locked" while insert query.Here is my code

 sqlite3_stmt    *statement;
        NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
        const char *dbpath = [[defaults objectForKey:@"dbpath"] UTF8String];

        if (sqlite3_open(dbpath, &studentDB22) == SQLITE_OK)
        {
            NSString *insertSQL = [NSString stringWithFormat:@"INSERT INTO Emotion_videos (name) VALUES (\"%@\")",filePath];
            const char *query_stmt = [insertSQL UTF8String];
                if (sqlite3_prepare_v2(studentDB22, query_stmt, -1, &statement, NULL) == SQLITE_OK)
                {
                    NSLog(@"shi h2345");
                    if (sqlite3_step(statement) == SQLITE_ROW)
                    {
                        printf( "could not prepare statement: %s\n", sqlite3_errmsg(studentDB22));

                    }

                }
            sqlite3_finalize(statement);
        }
        else
        {
                   printf( "could not prepare statement: %s\n", sqlite3_errmsg(studentDB22));
        }

I am able to insert data for two or three times but when it runs again,it shows database locked error.

rmaddy · Accepted Answer · 2012-10-31 04:17:08Z

2

You open the database but you don't close it.

You shouldn't use string formats to create queries. You should put ? placeholders in the query then bind the proper value. This takes care of things like properly quoting and escaping string values.

NSString *insertSQL = @"INSERT INTO Emotion_videos (name) VALUES (?)";

After you prepare the statement, call sqlite3_bind_text to bind the string value.

Also. don't use sqlite3_open, use sqlite3_open_v2. It's better and gives you more control.

answered Oct 31, 2012 at 4:17

rmaddy

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3 Comments

shivam Over a year ago

what will be the parameter in sqlite3_open_v2??

shivam Over a year ago

My query is running only for two times.Third time query is not executing neither app being crash. Help pls.

rmaddy Over a year ago

Do you close the database each time you open it? Are you running the code in the debugger? What is different the third time?

Anil Kothari · Accepted Answer · 2012-10-31 07:23:51Z

0

You have missed one of the important step while creating a database connection:-

Close Database connection before creating connection if it is already made.

   if (sqlite3_open([[self dataFilePath] UTF8String], &database)
    != SQLITE_OK) { sqlite3_close(database); NSAssert(0, @"Failed to open database");
    }

Use at the end of the function:-

sqlite3_close(database);

answered Oct 31, 2012 at 7:23

Anil Kothari

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