mysql

How to perform COUNT() or COUNT(*)

I have a list of tags in a database. Ex: villan hero spiderman superman superman I wanted to obtain a sorted list of the tag names in ascending order and the number of times the unique tag appeared in the database. I wrote this code: Ex: SELECT hashtag.tag_name , COUNT( * ) AS number FROM hashtag GROUP BY hashtag.tag_...

How to concatinate text on existing database entry?

I have a table, whose fields are id, name, link the link holds the name of the page like "link" = "index.php". Now I want to update this field and add "page=" in front of "index.php". Using this method I would like to update every entry in my table. My desired SQL syntax need to be something like this UPDATE mytable set link= 'page=...

How many indexes will actually get used?

I'm writing a page that does very simple search queries, resulting in something like: SELECT * FROM my_table WHERE A in (a1, a2, a3) AND B in (b1, b2) AND C in (c1, c2, c3, c4) AND And so on for a variable number of columns, usually ~5. If I create a separate index for each column (one for A, one for B, one for C, not (A,B,C)), will a...

PHP mysql_fetch does not return values

Hi, Being quite new with PHP, I cannot find any solution why this does not work. The query is OK and the resource is returned. But I dunno why fetch_assoc does not print values. Thanks $query=sprintf("SELECT ID,NAME FROM USERS WHERE PASS='%s' AND NAME='%s'",mysql_real_escape_string($p),mysql_real_escape_string($n)); $result=mysql_query...

how to undo mysql query?

How can I undo the most recently executed mysql query? ...

Inserting data into multiple tables through an sql view

Is there any way to insert data into multiple tables through a view in mysql? ...

How to organise team work on mysql databases?

How to organise team work on mysql databases? Probably, something like svn, but for databases ...

MySQL server's thread_stack parameter - what is it? How big should it be?

Couple days ago I got following error from MySQL database: Thread stack overrun: 68744 bytes used of a 196608 byte stack, and 128000 bytes needed. Use 'mysqld -O thread_stack=#' to specify a bigger stack. All documentation that I found says, that: The default is 64KB before MySQL 4.0.10 and 192KB thereafter. If the thread stack size ...

Is there a way to get a MySQL table defined encoding in PHP ?

I see i can get a MySQL database defined encoding in PHP using the function mysql_client_encoding(...), but is there a way to get a MySQL table defined encoding in PHP ? ...

Database design advice needed.

Hi all, I'm a lone developer for a telecoms company, and am after some database design advice from anyone with a bit of time to answer. I am inserting into one table ~2 million rows each day, these tables then get archived and compressed on a monthly basis. Each monthly table contains ~15,000,000 rows. Although this is increasing month...

Bulk Update in MYSQl

I have a site which has client side and admin side. There is a table called account History. which contains fields like uid | accountBalance | PaymentStatus | Date. Now this table has to be updated every month for all the paid users and the table is bulk. So what is the best way to update the table every month.Do i need to select all th...

Good strategy for copying a "sliding window" of data from a table?

I have a MySQL table from a third-party application that has millions of rows and only one index - the timestamp of each entry. Now I want to do some heavy self-joins and queries on the data using fields other than the timestamp. Doing the query on the original table would bring the database to a crawl, adding indexes to the table is not...

Error during data UPDATE in php

$sql = "UPDATE tblprofile SET name = '$membername' , f_h_name = '$fathername', maritalS = '$mstatus' , dob = '$dob' , occupation = '$occupation' , ...

Save phone calls data in a DB?

How would you save this data on a database: An user can make phone calls (id, date, hour, duration, outcome). The "outcome" can be, for example, to recall the client on another day (so I have to save the date, the hour, etc of this "future" call). How would you manage this data on a db? At the moment i have only a "Call" table. ...

Help getting the following create table function to work with mysql and C#

string createTable = "CREATE TABLE IF NOT EXISTS " + m_strDatabase + "_TimeLogs (logName VARCHAR(16), logTime INTEGER, logCountry TEXT, UNIQUE(logName)) TYPE=MyISAM;"; When this runs, no table is created. No errors either. Im using an ODBC connector. the variable passes in the db name, so that the table created would be users_Time...

How to know record has been updated successfully in php

$sql = "UPDATE...."; if(mysql_query($sql)) { $_SESSION['Trans']="COMMIT"; header("location:result.php"); exit; } else { $_SESSION['Trans']="FAIL"; $_SESSION['errors'] = "Error: Sorry! We are unable to update your Profile, Please contact to PNP HelpDesk."; h...

Complex mySQL Query (again)

My apologies that the question title is not more specific. I am working on a system that involves stock control and membership records. The current problem relates to the 'membership packs' that are given to new members on joining; there are a variety of membership types and each one gets a pack with several items in, no two packs are ...

Mysql optimization question - How to apply AND logic in search and limit on results in one query?

This is a little long but I have provided all the database structures and queries so that you can run it immediately and help me. Run the following queries:- CREATE TABLE IF NOT EXISTS `Tutor_Details` ( `id_tutor` int(10) NOT NULL auto_increment, `firstname` varchar(100) NOT NULL default '', `surname` varchar(155) NOT NULL default '', ...

Converting human readable date into integer values

Hello all, I am looking to do something really simple. Merely convert a string, such as 'december' into something I can use with MySQL (such as '12'). At the moment I use a dict, month_map = { 'december': '12', 'november': '11', 'october': '10', 'september': '09', 'august': '08', 'july': '07', 'june': '06',...

ALTER TABLE error

Can someone explain to me why I am receiving the following error? I want to rename the column "exerciseID" to "ID" in a mysql table using the following syntax. ALTER TABLE `exercises` CHANGE `exerciseID` `ID` INT( 11 ) NOT NULL AUTO_INCREMENT However I receive the following error: MySQL said: #1025 - Error on rename of './balan...