MySQL : Open-Source, Relational Database Management System

learn more… | top users | synonyms

1
vote
0answers
7 views

Is it possible to cascade delete a column value? [duplicate]

So say I delete catID from table A and table B has the same foreign key value? It's hard to explain so I'll try and show you with the two images below: items table Is it possible to delete the ...
0
votes
1answer
37 views

How to recover deleted records by mistake in Mysql

I am using Mysql.And by mistake I deleted very important info.Is there a way to recover or even to see the deleted info over a month ago?
0
votes
1answer
49 views

How to improve this query so it'll run quicker

I've got this query: SELECT m.vlanID, v.vlan_name, m.interfaceName, count(m.macAddress) as mac, n.nd_name, p.interfaceDescription, p.interfacePortType FROM macs m, network_devices n, ...
1
vote
0answers
12 views

fast execution analitycs database with thousand rows to displaying in php [migrated]

i've table with a thousand rows and i want to creating analitycs with chart display my front end php my table structure is and how i display this data : by user_agent column i display operating ...
1
vote
5answers
30 views

Anyway to identify mysql slaves have read upto which binary logs

I have multiple slaves reading from one master.. But few of them are keep disconnecting due to network issue. Is there any way that i can make sure before setting up the bin log purging script on ...
1
vote
2answers
36 views

Disaster recovery solution for MySQL

I have set a Master-master replication with the second Master running as read-only. This master-master setup is on the same location. Now I will have to setup an DR for this production at a different ...
0
votes
2answers
39 views

Setting up MySQL master-slave replication

I am trying to setup master-slave replication on MySQL 5.6. When I update my database in the master, the change is not reflected on the slave. When I show the process list on the slave it shows this ...
1
vote
1answer
69 views

Matching data in two tables

I'm teaching myself SQL and I ran into a question that may be related to joining tables. I'm just a bit unsure. Say, you have two tables, one listing the customer's creditcard_number, and one listing ...
0
votes
0answers
26 views

How to view the data from a .mysql file?

I have a .mysql database file. I need to open it and view the data. I've MySQL Server & MySQL Workbench installed into my Ubuntu 14.04. Now how do I open the .mysql file and view the data inside ...
1
vote
2answers
65 views

Select highest id of each type in mysql

I am creating a database that keeps track of backups on our various servers. The query that I am using actually seems to work for the most part. The only issue is that it isn't getting the highest ...
0
votes
1answer
23 views

Slow query - just error count

I deal with slow queries in whole project. I indexed heavily but the results are nowhere. I had a lot of logs (thousands per minute) from SCADA systems and I am trying to count them for each SCADA ...
1
vote
2answers
69 views

Slow SQL query with LEFT JOIN

What my query is doing: I have two SQL tables and I want to copy datarows from the one table to the other table. I am doing this for statistics. The source table includes all current ...
0
votes
1answer
14 views

Fulltext Search Doesn't Match a Hashtag

We maintain a table that looks like this to perform search queries on our forums database. I'll draw your attention to the FULLTEXT columns: CREATE TABLE `forums_posts_search` ( `post_id` ...
2
votes
0answers
51 views

SELECT … INTO variable results in NULL or idk

you can find all the relevant code on pastebin. The problem: the variable to_spend stays default. If I leave the default 0, it is 0, if change it to NULL, it is NULL. So the statement if(to_spend ...
0
votes
2answers
34 views

What storage engine do I need - Mysql?

I have designed a database and came to the point of actually deciding which storage engine is better for my case. I estimate that during the first few years I would have around 100,000 - 500,000 ...
1
vote
3answers
54 views

Users vs. People - where to keep the email address?

I'm designing an app similar to Facebook, called Headtome. I want to have users that create public profiles, including email addresses. Then, Mary can choose to message John, and that message goes ...
1
vote
1answer
24 views

MySQL queries taking very long/not finishing

I just started working with databases and have a problem with queries taking very long. My table has the following form CREATE TABLE table (column1 INT(10) AUTO_INCREMENT PRIMARY KEY, column2 ...
0
votes
0answers
7 views

CALL MySQL Stored Procedure in a C application crashes the application with segmentation fault

I want to use CURSOR of MySQL in an application written in C. I created a stored procedure CREATE PROCEDURE curdemo(IN id INT) BEGIN DECLARE a INT; DECLARE flag BOOL DEFAULT FALSE; ...
2
votes
1answer
28 views

How to create a relatively complex MySQL query

I'm not good with MySQL but have been trying to create a query that would join from three tables where: Table 1 (macs) is like this: ipAddr, vlanID, macAddress, interfaceName Table 2 ...
0
votes
0answers
22 views

Is mysqlreport still used?

The mysqlreport main page doesn't exist anymore, and the tool has not been updated since 2008. However, the tool is still available via package managers in Linux. On the other hand, it's difficult to ...
2
votes
0answers
15 views

Mysql History Trigger Auto Increment bug or problem

I want to log history of a table, I created a history table and triggers for update,insert and delete operations. I do my test on realtime replication slave. When a record inserted master's main ...
0
votes
0answers
46 views

Mysql query performance is really bad

I have a very simple query in MySQL which is taking hell lot of time. It ran for 18 hours and didn't complete Update OrderDetail OD Join TEMP_PARTMASTER_LATEST_UPDATES PM Using ...
0
votes
0answers
35 views

MySQL: Slow Query Performance - Parameter Sniffing?

For a personal weather project, I am trying to define and run the following stored procedure: DROP PROCEDURE IF EXISTS history_between$$ CREATE PROCEDURE history_between (IN date_start DATETIME, ...
0
votes
0answers
18 views

Using mysqldump and command line client

Very new to db admin. I am using Windows Server 2012 R2 in a testing environment, trying to teach myself basically. Looking into db replication. I have a very simple and newbie question. I am ...
2
votes
1answer
29 views

How to:: Master-Master replication

I have setup Master-Master replication on two servers. Now, my question is that if I need to have the second master as only read-only, what should I do? I tried doing mysql> flush tables with ...
1
vote
0answers
54 views

Space usage when copying

Short version Copy table took up more space than I expected or tested Why would that be? Could it be the replication / binlog? If so, what then is written to the binlog during this query: INSERT ...
0
votes
0answers
22 views

Mysql terribly slow on Xampp

I've looked if it was Apache, but on websites without a database, it loads pretty fast, but on my Joomla site the localhost takes like 15 seconds or more to load a page. I edited the hosts file of ...
0
votes
0answers
24 views

Doubt on Master-Master replication

I'm setting up a master-master replication where in the second master is only read only there by reducing the issues of conflicts. My doubt is that to reduce the downtime when my master goes down I ...
0
votes
1answer
32 views

Insert but Don't Commit MySql

I am pretty new to MySql and Databases, and I was wondering in python sometimes I forgot to commit after an insert, and then when I do then next insert and commit that one the, auto-incrementing id ...
1
vote
1answer
33 views

Best way to store data in tables

I've been thinking on how to store data efficiently in database tables, I'll give the examples in visual look. See pictures below. I've come to think to store data in database using compressed values ...
3
votes
1answer
47 views

identify gaps and islands

I have a database that has the following structure +---------------------+------------+---------------+ | timestamp | EngOilP_sd | CompOilLVL_sd | ...
1
vote
1answer
30 views

Losing the last column of data

After Loading data into the table and running a query on it, it tends to lose the last column of it. Like somewhere in import process it lost it. The file i was using was UTF-8 .csv format. A Is ...
-3
votes
0answers
20 views

duplicates of part.num to be summed and add another column called user [closed]

There are 3 columns part num, Qty and MO. Each MO has part numbers.So there might be same part numbers in MO's. Each part num has qty. So, if I group by part num, I get Qty. 1.There are duplicates of ...
0
votes
1answer
63 views

compare results between two select queries mysql

i'm making test application where users will input their select queries in input box and the application have to compare them if they are identical with "correct answer" query. "Correct answer" query ...
2
votes
1answer
32 views

Unique Index/Constraint with multiple columns, one column is nullable

My questions is whether it's possible to have unique index comprised of multiple columns where one of the columns may contain NULL. Example: A table named 'regulated_person' has a number of columns ...
0
votes
2answers
58 views

How to know which user update/insert or delete in MYSQL database?

Using the triggers I could make the establishment of a historic recordings in MYSQL tables where i detect all changes in my database. My problem is that I want to know which user made ​​the change in ...
6
votes
3answers
182 views

Implementing versioning system with MySQL

I know this has been asked here and here, but I have the same idea with a different possible implementation and I need some help. Initially I had my blogstories table with this structure: | Column ...
0
votes
1answer
34 views

Mysql create trigger if not exist

I have a script that creates triggers, I would like to run it multiple times and if a trigger already exist it needs to skip the creation part. Is there a "create if not exist" in mysql triggers? I ...
1
vote
3answers
60 views

MySQL restore old backup over new data

We have a MySQL backup. Did some changes on our database and some data was lost. In the mean time new records were added. We have to restore the mysql backup over our latest data. Some of the tables ...
0
votes
1answer
29 views

replication filtering replicate-rewrite and do-table Mysql 5.6 (innodb engine )

i have a master / slave replication setup based on statement based replication. On master database name DB1 , i have 5 tables and i want to replicate only two table on slave's database name DB2. Also ...
3
votes
2answers
158 views
+250

Schema question

I'm creating a schema for product failures and repairs and would appreciate feedback on the schema. The database is intended to capture all product failures and corresponding repairs. A product can ...
0
votes
2answers
54 views

Remove duplicates from multiple joins

I'm using WordPress $wpdb->get_results for this query (it is simplified for question purposes): SELECT customer.id, customer.name, address.address appt.appointment_date, pay.date FROM customers ...
0
votes
1answer
24 views

Based from experience, is dreamfactory better paired with a RDBMS like MySQL or NoSQL like MongoDB

This is our first time to create a data logging web application and we have chosen to use Dreamfactory as the backend framework. We have been used to with MySQL from the past with small amount of data ...
0
votes
1answer
48 views

Mysql Slow when join query running increaed

Our Mysql dedicated server box always have around 40 - 80 active user connection , so the query speed very good and Cpu usage low . (around 4 - 8 core from 24 core) but sometimes when some wordpress ...
0
votes
0answers
32 views

MySQL drops every connection, even locally

Every time I run a MySQL query it has to reconnect mysql> show variables like '%timeout%'; ERROR 2006 (HY000): MySQL server has gone away No connection. Trying to reconnect... Connection id: 60 ...
2
votes
0answers
27 views

Getting error 1064 in automatically-generated code from MySQL workbench [duplicate]

I have started using mySQL workbench (Version 6.3.4.0) and I have used the EER Diagram tool to design a schema. So far, so good. However, when I try and run the Forward Engineering, I get the error ...
2
votes
2answers
42 views

Finding differences between two tables takes too long

I'm trying to find the diff of two tables using a left join. My query is as follows: CREATE TABLE my_diff (INDEX my_index (name, type)) SELECT AA.name, AA.type FROM AA LEFT JOIN BB USING (name, ...
-2
votes
1answer
38 views

How to handle huge amount of data in Mysql [closed]

i want to develop a quotation management system,which receives 30-40 quotations per day. we need to handle nearly 1 lac records per month we need to insert quotations using excel sheet as input. how ...
1
vote
1answer
185 views

How do you calculate how much hardware resources you need for a database?

We are in the process of scaling our database servers. I was wondering how should we calculate how much hardware resources we need for our databases? Here is a little bit information about our ...
0
votes
0answers
32 views

call a stored procedure from sql window in PHPMyAdmin

I have a simple stored procedure that selects rows from a table. In phpMyAdmin, in the list of my procedures, if I click the Execute option, it executes properly, returning the desired rows, and ...