How do I select a random row from the database based on the probability chance assigned to each row. Example: Make Chance Value ALFA ROMEO 0.0024 20000 AUDI 0.0338 35000 BMW 0.0376 40000 CHEVROLET...

I set two user-defined variables as shown below but after some time, I forgot the names: SET @a = 2, @b = 3; So, does MySQL have the command that displays all user-defined variables?

I'm using MySQL in localhost (in ubuntu and also in windows). I want to set a global variable, and I have tried in all ways but even though I get an "ok" message from mysql, then when I d...

Is there a possibility to do something like this? SELECT @z:=SUM(item), 2*@z FROM TableA; I always get NULL for the second column. The strange thing is, that while doing something like SELE...

The following is the simplest possible example, though any solution should be able to scale to however many n top results are needed: Given a table like that below, with person, group, and a...

Is there is a way to delete records using WHERE IN @VARIABLE? -- DEMO TABLE CREATE TABLE people ( id int AUTO_INCREMENT NOT NULL, name varchar(100), age int, active smallint DEFAULT 0, PRIMAR...

Hi I am looking to create a table with date as column name. I am using this code to Add column to the table: DROP PROCEDURE IF EXISTS filldates; DELIMITER | CREATE PROCEDURE filldates(dateStart ...

I am using SET GLOBAL <variable> = <value> to modify dynamic settings in mysql and I am wondering if there is some way to get the default value for each variable? For instance, if I use...

From MySQL Manual the output of the following query is not guaranteed to be same always. SET @a := 0; SELECT @a AS first, @a := @a + 1 AS second, @a := @a + 1 AS third, @a := @a + 1 AS fourth, @...

I have a MySQL query which works fine when executed directly on my local MySQL Database, but shows a different result when executed via PHP. SELECT a.id, a.title, a.public, a.sysstamp, a.password,...

We have a table in MySql with arround 30 million records, the following is table structure CREATE TABLE `campaign_logs` ( `domain` varchar(50) DEFAULT NULL, `campaign_id` varchar(50) DEFAULT NUL...

I've searched around for this, but all the similar questions and answers are just different enough not to work. I have a table with the following fields: person, thing, purdate. A new record is en...