MySQL : Open-Source, Relational Database Management System

learn more… | top users | synonyms

0
votes
1answer
16 views

How to generate auto increment values for my duplicate column in my sql?

How to display when i was run to find duplicate values from my table at this time i want to add new column in select statement with auto increment values SELECT * FROM tutorials_tbl WHERE Lscno IN ...
0
votes
2answers
14 views

online Hostel management system ER diagram

hi, i have created a er diagram for online hostel management system please advice me this diagram make sense or need improvement Regards
0
votes
2answers
74 views

JOIN on variable number of columns

I have the two tables courses AND something_about_courses: courses course_code course_session course_type something_about_courses course_code course_session some_description To ensure that I ...
0
votes
1answer
40 views

join from different tables gives same result, but it shouldn't

This is the code I'm using and I'm having a problem with it. SELECT `disenos`.*, `votos`.`valoracion`, `usuario_contacto`.`nombres`, `usuario_contacto`.`apellidos`, `users`.`username`, ...
0
votes
2answers
158 views

Hierarchical Structure

Every single user has say, 3 of GROUP_A, 10 GROUP_B's per GROUP_A, and 20 GROUP_C's per GROUP_B. And each of the 20 GROUP_C's involve lots of inserts/deletes... I'm not an expert, but I've done ...
2
votes
3answers
52 views

Difference data between adjacent rows

I have a table (called Visits) with ReqTime DATETIME NOT NULL column AND Duration INT UNSIGNED column. Duration should be set to the difference of ReqTime for two adjacent rows. But Duration is not ...
0
votes
1answer
63 views

Mysql 5.6.17 drop large table locks the server for minutes

We run Mysql 5.6.17. Dropping a large InnoDB table 10GB caused the whole server to lock for about 40 seconds. We have 55GB innodb buffer pool size. I read bunch of old bugs that could be the source ...
2
votes
1answer
572 views

Designing database with Category and Tags for Posts - Seeking for guidance/advice

I'm not really a database novice but I'm not an expert either. Problem: I'm having this difficulty on designing my Post, Category and Tags relationship. I've read Normalization many times but could ...
0
votes
1answer
99 views

Please suggest my.cnf configuration based upon mysqltuner findings

I have been facing a lot of slow browsing on my site nerdeky.com. My server administrator suggested me to use mysqltuner.pl to find and tune my databases. Can anyone select me what should be the good ...
0
votes
1answer
21 views

How does subpartitioning actually work and what physical files are created?

I can't understand how the subpartitioning works in mysql. I am reading the following example: create table invoices ( customer_id int not null, product_id int not null, amount decimal ...
3
votes
2answers
145 views

Problem in Fetching Result set in Desired Format

I have 2 tables having the following columns Person ------ person_id, first_name, middle_name, last_name Items ----- person_item_id, person_id, item_type, status, ordered_date The query is ...
1
vote
0answers
29 views

Query does not use index (according to EXPLAIN SELECT)

Can anyone give me an indication, why this query does not use the Key on the table 'gtg'): ...
0
votes
1answer
686 views

Table Design - User Management

I have designed a database design for a simple User Management System, this system consist of the following things, User - A user may be a Vendor / Employee / Buyer. User - A user may have more than ...
2
votes
1answer
730 views

MySQL - run SELECT statement on another server without defining the table structure

In MySQL I can query information on another server using federated tables, as long as I've defined the same table structure locally. In MS SQL Server, however, I can run any SQL statement against a ...
2
votes
0answers
32 views

Emulating WITH clause in MySQL/query perfomance review

I have never really worked with MySQL queries till this last week. I was tasked with making a simple tool for my department that tracks contacts. Here are the 2 tables and the type of data they ...
0
votes
1answer
126 views

How can i import 150GB database after deleting ibdata1,logfile in MYSQL?

I have 150GB database and my ibdata1 file size is 240GB so i want shrink the ibdata1 file so for that i have to export the DB and then drop the tables and then stop mysql, delete the ibdata1 file and ...
0
votes
4answers
952 views

How can I replicate some tables without transferring the entire log?

I have a mysql database that contains some tables with private information, and some tables with public information. I would like to replicate only the tables containing public information from one ...
1
vote
2answers
41 views

MySQL user without SUPER privilege

This may be a simple question and may not be the right place to ask but I couldn't find any useful information from Google. Here is my question. When creating users in mysql using grant all ...
3
votes
1answer
2k views

MySQL: Lock wait timeout exceeded

I have a developer that has been trying to alter a large table (~60M rows). Via LiquidBase/JDBC they're running ALTER TABLE foo DROP FOREIGN KEY fk_foo_1; Today while it was running I checked in ...
2
votes
1answer
36 views

MySQL CPU & Memory Spikes

Every couple of days, my server's CPU and memory usage spikes up to 100%, making our vBulletin forum almost unusable for 5-10 minutes. CPU is typically at 1-2, Memory at 3GB. During the spikes, CPU ...
1
vote
1answer
46 views

Need help with data model

Schema does not list all fields, but only the relevant ones User adds credits/funds to his account using paypal or Internet Banking (which has to be verified manually, and approved, so the 'status' ...
2
votes
3answers
115 views

Why MAX() of SUM() giving wrong output?

I have a table employee id name salary city 1 ram 50000 c1 2 sham 20000 c2 3 jadu 80000 c1 4 madhu 90000 c4 5 hari 10000 c2 6 gopal 34000 c3 7 ...
1
vote
1answer
62 views

Pivot table with MySQL

I'm trying to create a pivot table like output (cross table? Not entirely sure about the difference). The idea is to have rows, columns and summary values (specifically: distinct count). The data ...
2
votes
3answers
120 views

Can I use PHP function strtotime() in SQL queries?

I have this table, and I need to use a PHP function in the query. id time lastTime 1 08:02 2 08:04 3 08:30 I am using this query with the strtotime(), and it's not working: ...
1
vote
2answers
202 views

How to migrate data from SQL database to MySQL including flat files?

one of my friend has asked some asp developer to make online application where user can upload files also. jpg, doc, pdf and all these files are saved in SQL database as flat file. Now my friend asked ...
1
vote
1answer
256 views

Two different MYSQl instances on same machine?

I have MySQL 5.6 installed (Linux). /var/lib/mysql /etc/my.cnf I have a cold backup that I am recovering: /var/lib/mysql_backup /etc/mybackup.cnf In April I was able to get the backup started ...
0
votes
3answers
123 views

From freelancer to team of two : best way to share/sync db?

I am a webdev. I have just hired a dev. Before that I was alone. Thus, I have to change a bit my organization. I am looking for the best way to develop on the same database (MySQL). I am considering ...
0
votes
1answer
43 views

Intermittent connection errors

I am experiencing occasional connection errors from my webserver to one of my databases. The code attempts to connect. If it fails, it sleeps for 1 second, then retries, then (if it still fails) ...
0
votes
2answers
92 views

Anyway to optimize complex view?

In the system, Files can belong to either products, clearances, business_lines or titles. Clearances are records that represent a combination of a title and a product. Products are collections of ...
0
votes
0answers
13 views

replication error Error Duplicate entry… for unique key

I have two database that one of them is replicated of another one,my tables have unique key on some column ( NOT primary key ),so if in replication process an Error Duplicate entry..... occur,these ...
0
votes
2answers
175 views

database structure - complicated requirements

I have a project to build a website but it's complicated and I'm having trouble figuring out what the best way to build the database would be to handle these particular requirements. The site is for ...
1
vote
3answers
104 views

Restore large MySQL dump thorugh EasyPHP

I am trying to upload large files on easyphp but as there is limitation on this software and large databases cannot be uploaded. Is there some other software that allows to import large databases? ...
1
vote
1answer
35 views

Should I drop this column or is there a query that can achieve a results table without duplicate columns?

I use a column named active in several of my database tables to adjust whether a particular entry/row/user/etc should be included in future query result tables instead of deleting the information. ...
0
votes
1answer
165 views

Restrict access to rows by usename

In my database i store data of different users (e.g. addresses or invoices) in the corresponding tables. I want to make sure that a logged in user only has access to it's own data in the tables (so ...
0
votes
1answer
84 views

Need help optimizing query to prevent full table scans

I have the following query, which while it works, is also doing a full scan on each left joined table (the log* tables). I thought by using a subquery in the FROM that this would eliminate the ...
0
votes
1answer
582 views

Inserting query result to another table hangs on “Copying to temp table on disk” on MySQL

I started the process of inserting returned results to another table. The query groups the rows in respect of indexed IDs. This causes 149,000,000 rows to be decreased to 460,000 rows. The query ...
0
votes
1answer
81 views

Whether to use or not to use: DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP

In one Database table, created_at & updated_at are defined as: `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP `updated_at` timestamp NOT NULL DEFAULT ...
0
votes
2answers
37 views

How to store user's language knowledge (150+ languages) in mysql DB

Users in my website must be able to select languages they know (English, German, etc), so I have a table languages with 150 languages (id, name) and table users (id and a lot of other fields). ...
1
vote
1answer
592 views

Slow insert with MySQL full-text index

I use a full-text index in a MySQL table, and each insert into this table takes about 3 seconds. It seems that MySQL rebuilds (a part) of the full text index after each insert/update. Is this right? ...
2
votes
2answers
3k views

query_cache_type = 0 vs query_cache_type = 1

Recently, I moved from standard MySQL to Percona, and used the Percona Wizard to generate my.cnf. However, I can see that, by default, the generated settings for my.cnf use query_cache_type = 0. ...
3
votes
1answer
54 views

Row size error with MySQL

I'm running a MySQL server on my Macbook (for testing). Version is 5.6.20 from Homebrew. I started running into "Row size too large" errors, and I've been able to reduce it down to this test case. ...
1
vote
2answers
51 views

Query to Access a specfic data in the row using python

Am using wordpress and phpmyadmin for handling my database Below is the code I use to view entries on my form using python. In the form I ask users to check/uncheck specific questions. It works as ...
1
vote
1answer
25 views

Adding time to an event that runs on a weekly basis

I have this event that runs every Thursday CREATE EVENT le_drop_database ON SCHEDULE EVERY 1 WEEK STARTS CURRENT_DATE + INTERVAL 3 - WEEKDAY(CURRENT_DATE) DAY DO BEGIN drop database carbon; ...
-1
votes
2answers
21 views

How to convert time to minutes in Mysql

I want to change the time to minutes and update the table and insert the value in the field minutes Id time minutes 1 01:00 ? 2 00:44 ? 3 01:13 ? ...
0
votes
1answer
46 views

Transfer all read request to Slave in Master-Slave MySQL

I have configured master slave on my system (MYSQL). Now, is there is any script or way available or possible to transfer all read request to SLAVE. So, let me make my question here more clear. I ...
0
votes
2answers
64 views

Msg 2627 Violation of PRIMARY KEY constraint

trying to make a database for teams in a tv show here. but when I try and insert data into tblShowteam the following error made its appearance. Msg 2627, Level 14, State 1, Line 2 Violation of ...
2
votes
1answer
39 views

Is data warehouse monitoring same as database monitoring?

I have a requirement, where data warehouse population is to be monitored. I am in confusion, and needed a clear picture. Is data warehouse different than database? eg. For monitoring database we ...
0
votes
1answer
39 views

Gets records by max date and hour

I have this query: "SELECT * FROM `" . $table . "` WHERE STR_TO_DATE(data, '%d/%m/%Y')=(SELECT max(STR_TO_DATE(data, '%d/%m/%Y')) FROM " . $table . ") AND hour=(SELECT MAX(hour)-".$delta_hour." ...
1
vote
1answer
13 views

Import multiple CSV fields into one MySQL field

I'm trying to import our CSV data log into our MySQL. The first two fields of the CSV are Date and Time, and I would like to combine that into one date time (which can be searched) onto MySQL. CSV: ...
0
votes
0answers
13 views

Optimal Database Configuration

We have developed a Multilingual website based on Drupal platform. I want to know the optimal configuration for MYSQL database (an possibly server hardware) if we were to expect 50,000 hits per hour ...