I have done all sorts of things to understand what is actually wrong with the code, but I just couldn’t figure out what was causing this error. Below is class called Topic : class Topic { // Init DB variables private $db; /* * Constructor */ public function __contruct() { $this->db = new Database(); } … Read more
I have a fairly good feel for what MySQL replication can do. I’m wondering what other databases support replication, and how they compare to MySQL and others? Some questions I would have are: Is replication built in, or an add-on/plugin? How does the replication work (high-level)? MySQL provides statement-based replication (and row-based replication in 5.1). … Read more
I have a teams table and a players table and I’m wanting to find all teams that do not have players associated with them. The players table is associated via a team_id column. I’m using Ruby on Rails for this so I have a Team and a Player model. Answer It may perform better doing … Read more
I am looking at FILESTREAM attribute in SQL Server to store files in it. I understand it stores the files on hard drive and stores the file pointer/path information in DB. Also, maintains transactional consistency in the process. There also seems to be a limitation “FILESTREAM data can be stored only on local disk volumes” … Read more
I’ve got the problem that select datepart(ww, ‘20100208’) is returning as result week 7 in SQL Server 2000. But 08.02.2010 should be week 6 according to the ISO 8601 specification! This is causing problems in delivery week calculations. What should I do to get week number values according to ISO 8601? Answer You can do … Read more
I created a query that takes a database backup at certain specified location. I want to use it as a stored procedure but this should act as a global stored procedure so that whenever this SP is called. Then database backup is taken. It uses DB_Name() to take database backup of owner database. Is it … Read more
I had the below query working in mysql 4.1, but does not in 5.0: SELECT * FROM email e, event_email ee LEFT JOIN member m on m.email=e.email WHERE ee.email_id = e.email_id The error: 1054 (Unknown column ‘e.email’ in ‘on clause’) Answer You can only refer the tables previously joined with the JOIN clause in the … Read more
count(*) and count(column_name), what’s the difference in mysql. Answer COUNT(*) counts all rows in the result set (or group if using GROUP BY). COUNT(column_name) only counts those rows where column_name is NOT NULL. This may be slower in some situations even if there are no NULL values because the value has to be checked (unless … Read more
I am using mysqldump to take backup of my database, but the command is not working.. the command i am using is mysqldump -u root dbname> ‘c:\backupdatafolder\backup.sql’ i am running this command in MySQL cli but not running,..is there any thing wrong in the command? Answer You are supposed to run that on the command … Read more
Suppose I have a date 2010-07-29. Now I would like to check the result of one day ahead. how to do that For example, SELECT * from table where date = date(“2010-07-29″) How to do one day before without changing the string “2010-07-29”? I searched and get some suggestion from web and I tried SELECT … Read more
