Have you ever come across a situation called NO MORE SPOOL SPACE?  My friend does and hence I studied a bit about Teradata. The query: SELECT DISTINCT fieldname FROM tablename; The error: “NO MORE SPOOL SPACE”. Correct, the problem wasn’t related to MySQL, that was for something called Teradata. Initially, I could see that query should be […]

In this article I’m showing how to retrieve result based on today, week and month using mysql query. To learn the techniques just visit http://thinkdiff.net/mysql/getting-rank-today-this-week-and-this-month/

In my previous article I’ve shown how to get rank using mysql query. Now I’m showing how to retrieve result based on today, week and month using mysql query. Actually I also implemented this in my quiz project so I’m sharing this with you.

For the table structure please look my previous article http://thinkdiff.net/mysql/how-to-get-rank-using-mysql-query/

Task 1: I’ve to retrieve those users rank who played the game today.
Solution: Look at the query

SELECT uid, participated, correct, wrong from quiz_user
    WHERE DAYOFMONTH(CURDATE())=extract(day from updated)
    ORDER BY correct DESC, participated ASC
    limit 30

So the above query returns the result of those users who played today. Here

CURDATE() …

In this article you’ll learn how to get user’s rank in mysql query. Check the link http://thinkdiff.net/mysql/how-to-get-rank-using-mysql-query

Yesterday a friend came across an oracle query problem: Consider below table: cid cname.... cdata 1 x xxxx 1 x xxxx .. 2 xzzz fjnd 3 a evddd Now the…

The post Oracle query-eliminate duplicate but one using rowid first appeared on Change Is Inevitable.

Introduction

A question I recently saw on Stack Overflow titled Faster way to delete matching [database] rows? prompted me to organize my thoughts and observations on the subject and quickly jot them down here.

Here is the brief description of the task: say, you have 2 MySQL tables a and b. The tables contain the same type of data, for example log entries. Now you want to delete all or a subset of the entries in table a that exist in table b.

Solutions Suggested By Others

DELETE FROM a WHERE EXISTS (SELECT b.id FROM b WHERE b.id = a.id);

DELETE a FROM a INNER JOIN b on a.id=b.id;

DELETE FROM a WHERE id IN (SELECT id FROM b)

The Problem With Suggested Solutions

Solutions above are all fine if the tables are quite small and the …

An example of a basic MSSQL (Microsoft SQL Server/SQL Server Express) query using PHP.

1
2
3
4
5
6
7
8
9

$szQry = "SELECT column1, column2 FROM foo";
$szDBConn = mssql_connect("host","username","password");
mssql_select_db("database_name", $szDBConn);
$saResults = mssql_query($szQry, $szDBConn);
while($obResults = mssql_fetch_row($saResults))
{
   echo $obResults[0]." ".$obResults[1];
}
mssql_close($szDBConn);

Comments/description of Example

Line #1

SQL statement that will be sent to the MySQL database server.

Line #2

MSSQL database login credentilas; host (127.0.0.1), username and password.

The “host” is the server name or IP address of your database server. If your host has multiple instances the “host” value would be formatted like so …

Update

Ok, as Morgan quickly found out: I'm incredibly stupid. Read his comment and you'll know why. Ok, you'll not know why but you'll know that I am.

Really cool to see Chris taking up blogging as well

He has written nice little example about inserting comments into queries to distinguish the client’s IP when they are funneled through the proxy. Reading the comments about this little trick making the query cache not work, I couldn’t help thinking that those are wrong. I vaguely remembered that in some recent version this shortcoming was fixed, so I decided to run a little test on 5.1.30 to verify:

mysql> select concat(@@version_comment, ' ', @@version); …

Update

Ok, as Morgan quickly found out: I'm incredibly stupid. Read his comment and you'll know why. Ok, you'll not know why but you'll know that I am.

Really cool to see Chris taking up blogging as well

He has written nice little example about inserting comments into queries to distinguish the client’s IP when they are funneled through the proxy. Reading the comments about this little trick making the query cache not work, I couldn’t help thinking that those are wrong. I vaguely remembered that in some recent version this shortcoming was fixed, so I decided to run a little test on 5.1.30 to verify:

mysql> select concat(@@version_comment, ' ', @@version); …

Update

Ok, as Morgan quickly found out: I'm incredibly stupid. Read his comment and you'll know why. Ok, you'll not know why but you'll know that I am.

Really cool to see Chris taking up blogging as well

He has written nice little example about inserting comments into queries to distinguish the client’s IP when they are funneled through the proxy. Reading the comments about this little trick making the query cache not work, I couldn’t help thinking that those are wrong. I vaguely remembered that in some recent version this shortcoming was fixed, so I decided to run a little test on 5.1.30 to verify:

mysql> select concat(@@version_comment, ' ', @@version); …