Questions tagged [mysql]

All versions of MySQL (not Microsoft SQL Server). Please also add a version-specific tag like mysql-5.7 if that is relevant to the question.

Filter by
Sorted by
Tagged with
2
votes
2answers
233 views

Beginner problems administering users on mysql

Very new MySQL user here. Two questions for the community. I seem to have created an account that I can't delete/drop. I can't seem to get MySQL to actually require newly created accounts to require ...
2
votes
2answers
2k views

Why restoring a large sql file via SSH seems to quit partially through the process

I have a large (~5GB) .sql file I am attempting to restore via SSH, it seems to quit in the middle of the restore process. When I come back hours later after issuing the command (the file has 7 ...
3
votes
3answers
1k views

Is this database fine for calculation?

I am doing an application called as Invoice Application.For that I have my database is like this. Now my problem comes when I am taking the tax part in my database.As I have made tax as an option ...
3
votes
1answer
13k views

how to fetch different data on compare rows of two tables

I have two tables in my database, one is user_app table in which user info are stored, table are as: +--------------+--------------+------+-----+-------------------+-----------------------------+ | ...
6
votes
1answer
4k views

Optimizing MySQL for Read-Only?

We have 14 GB worth of CSV's which total 138 million rows. I imported this into a MySQL table first with InnoDB, and then tried again with MyISAM. In both cases, a simple SELECT on primary key (...
7
votes
3answers
18k views

How do I calculate COUNT(*) for a range without needing to use multiple queries in mysql

I am using MySQL and I need help using COUNT(*) for a range of values within a table. I have a table named PERSON (In the live system I expect several hundred thousand records or more). Name ...
2
votes
1answer
153 views

Several values from different tables

I'm totally lost here and not know how to get this to work and hope any can help me here. I have several tables: default_users, default_profiles, default_status, default_comment and latest ...
1
vote
1answer
3k views

“Mysql has gone away” heavy multiple insert

I am stuck because Mysql server will go away after executing this part of code this function will update the database with the new RSS feeds which are stored in ToUpdate but Mysql stops working. Every ...
2
votes
1answer
165 views

MySQL: self-administration for multiple users

My MySQL users have rights to administer their own databases, including create/drop database. I do not have a shared phpMyAdmin installation, however I do let users install it themselves. Most of the ...
8
votes
1answer
3k views

Can I have an InnoDB master and MyISAM slaves with Full-Text for searching?

I'd like to use InnoDB on the master, for its transactional ability, but MyISAM on the slaves for the full-text search ability. Is this possible?
2
votes
0answers
226 views

Get all comment.message, status.message, users.* and profiles.* where users.user_id exists in friend.friend_id or friend.user_id

I need some help building this query because it's a bit complicated at least for me. I need to get all comment.message, status.message, users.* and profiles.* where users.user_id exists in friend....
1
vote
2answers
229 views

Is possible to optimize this query or it's already optimized?

I've three tables: default_users, default_profiles, default_friend. This are the SQL for each one: -- -- Table structure for table `default_users` -- CREATE TABLE IF NOT EXISTS `default_users` ( `...
3
votes
1answer
2k views

query generate the information one column in two columns in one query

I have a question related with a query in sql. I have the next table: id name 1 name1 2 country1 3 name2 4 country2 I need to call the results so: ...
2
votes
3answers
392 views

designing multiple tables while eliminating duplication?

As I'm working on an educational website, I'm facing a problem with my database design scheme - I can't find the correct design that eliminates duplication in the tables I'm creating. What I'm trying ...
0
votes
2answers
130 views

Tiered permissions to generate conditional data access

I am working to improve the confidentiality and access level of the information presented within a program interface over top of a MySQL database. My goal is to create a two tier system: one based on ...
6
votes
2answers
5k views

mysql transaction vs lock

I have a question regarding MySQL locking and transaction management. My Question is ..does mysql takes lock on the the tuple/table on which I am doing select/update in a transaction ?
3
votes
3answers
4k views

Does the MySQL primary key affect the efficiency of a SELECT query?

Does the primary key serve any purposes apart from uniquely identifying a specific row? For example, a table with an autoincremented primary INT key could greatly aid in search due to the option of ...
3
votes
3answers
9k views

Memory problems with MySQLWorkbench

I'm currently using MySQLWorkbench 5.2.40 on my PC (8GB rRM, Corei7). I have a table with almost 1.5 million records, which I need to visually look over. Surprisingly, the total size does not exceed ...
3
votes
2answers
6k views

Similar function NOWAIT in MySQL

Select for update nowait doesn't work in MySQL 5x (innodb). Is there any function like NOWAIT in MySQL?
3
votes
1answer
8k views

error 1118: row size too large. utf8 innodb

I have tried to find a solution guys, and I am guessing that someone has met this before. But I cannot get hits down below 5000... most of which don't match my question. Using MySQL 5.6 - windows (...
5
votes
1answer
400 views

Query for data that is not there

I have this setup attendance table: ------------------------------------------ | member_id | attendance_date | event_id | ------------------------------------------ attendance indeces ---------------...
4
votes
1answer
133 views

Problem joining two tables in MySQL

I'm new to MySQL. I'm having trouble in joining two tables: SELECT e.resourceName FROM resources_in_room r JOIN resource e ON r.resourceId=e.resourceId WHERE r.roomId=2; Table resources in room: ...
4
votes
1answer
3k views

How do you extend the tablespace when using innodb_file_per_table?

With innodb_file_per_table off, you can create multiple tablespaces on multiple devices if necessary to manage growth, balance I/O, etc. With the option on, how do you control growth of the files? Do ...
0
votes
1answer
2k views

InnoDB - Use combined index with primary key on GROUP BY

As far as I know, an InnoDB index always contains the primary index. I cannot get the following to work: SELECT t1.a FROM table_1 t1 LEFT JOIN table_2 t2 on t1.id = t2.refid WHERE t1.b = 99 GROUP ...
2
votes
0answers
1k views

MySQL re-install fails under Mountain Lion

I have problems to reinstall MySQL on Mac OS X after it was running on my system. I uninstalled it because the PreferencePane wasn't working as expected, using the procedure described here: http://...
0
votes
1answer
91 views

Table and query design options

We have a alert table which have deviceID as a foreign key. At present one alert just refers to one devive so things works smoothly with join. The problem start now when one alert now is to refer to ...
3
votes
3answers
1k views

Is it possible to pass parameters to pt-table-checksum using an options file?

We're using Percona's pt-table-checksum for MySQL replication integrity check. Is it possible to pass some or all of the options using some sort of configuration file? For instance, can we write the ...
8
votes
4answers
7k views

How can I speed up “show columns” on MySQL?

My application depends on running "show columns" for certain tables. It takes about 60ms to run, whereas all our other queries take under a ms. Querying information_schema directly is even slower. ...
19
votes
2answers
78k views

Get a fixed value on a select

I need to do a SELECT query where I get the value of the field "money". The field doesn't actually exist in the database. I just need the query to return this field with a fixed value; in this case ...
1
vote
2answers
57 views

Why this query returns rows that I don't want to be there

I'm trying to running this query: SELECT * FROM (`default_users`) LEFT JOIN `default_profiles` ON `default_profiles`.`user_id` = `default_users`.`id` WHERE `default_users`.`group_id` ...
2
votes
1answer
19k views

Enabling InnoDB on an existing MySQL production server

We have a MySQL 5.1.59 server that has 30-40 existing MyISAM databases. I need to deploy an application that requires InnoDB databases. Can I just enable/configure InnoDB in /etc/my.cnf and restart ...
1
vote
1answer
4k views

Can we back up mysql databases by copying files?

I tried to reinstall mysql on my machine, but it keeps failing. Everytime it fails, it does this locking and that locking and future effort would fail again. Finally I decided to do truly clean ...
0
votes
1answer
266 views

What are the different connections of MySql?

I have a software(toad for mysql) to connect to my MySql database. We have to provide some data('username','password' etc) to this Software to connect database. There is a field known as 'connection ...
3
votes
2answers
12k views

Remove the last character from Variable String

I have a few variable data in the column "email". For example: roy2087@gmail.com123 sg123@yahoo.compori How do I get rid of the characters after .com? I used Replace(email,'.com%',gmail.com), ...
61
votes
1answer
26k views

How do I swap tables in MySQL?

Suppose, I have a table foo, which contains some statistics that are computed every now and then. It is heavily used by other queries. That's why I want to compute more recent statistics in foo_new ...
0
votes
2answers
7k views

Converting Python's date format to a MySQL

First of all I hope this is the right place to ask. I have a Python script which parses data from a few links. In the parsers I parse also the date of the last modified article. This is the output ...
3
votes
2answers
1k views

How does compound index help speed up query?

Say we have a bunch of column in mysql table. Latitude Longitude Say we make an index (Latitude and Longitude) Well, the index will sort by Latitude first and IF the Latitude is the same it'll sort ...
3
votes
3answers
2k views

Unique combination key MySQL

Lets say I have a table with 3 fields: id1 id2 mapTypeId What I want is a primary/unique key that is any combination of id1 and id2. For example if I have this record already in the database: 1, 2,...
4
votes
2answers
5k views

MySQL Cluster: Problem Connecting the SQL node

In a MySQL cluster I have three hosts, one with a manager node, and the other two are each both a data node and sql node. Connecting to the manager is possible, however only as [ndbd] and not [mysqld]....
4
votes
2answers
946 views

fast bulk incrementing in MySQL

I have one big table foobar describing a many-to-many-relation and containing millions of foo's, millions of bar's and every bar having several hundereds of foo's -> billions of rows. CREATE TABLE `...
5
votes
2answers
23k views

Reset MySQL root password in LAMPP server on Ubuntu

I forgot the password I changed for the root user of MySQL. I'm logged in as root user and when I do # /opt/lampp/lampp security it gives result as XAMPP: Quick security check... XAMPP: Your XAMPP ...
0
votes
2answers
4k views

MySQL Triggers Different Database Different Server

I have two databases, each on a separate server. Each database has a number of similar but not identical tables. I need to combine the records from these similar tables into a new database, which is ...
2
votes
1answer
2k views

Does MySQL have a limitation of one index per query?

MySQL supports spatial index. However, all the spatial index can do is find points in a box. It can't do fancy stuff like find the nearest 1000 points, etc. I think, and I don't know where I went ...
9
votes
1answer
314 views

Power went out - Did query finish?

Is there a way to check and see if a query finished? I ran 3 very long running update queries (+/- 25 hours each) as I went out the door for vacation last week. Unfortunately, somewhere during the ...
10
votes
3answers
21k views

MySQL Editor Hangs on attempt to Launch

I have just downloaded the latest Community Installer (5.5.27) along with the MySQL WorkBench (5.2.41). I clicked OK on all default settings on setup. When I try to "Open a connection to start ...
2
votes
5answers
314 views

How to shard 14 gb of data for archival database?

We have 14 GB worth of CSV's containing product information, with each CSV being all the records for a US state. We now want to store this in a database. There would be ~130 million records. The ...
11
votes
2answers
229 views

Optimization problem: compound clustered keys, flag conditions and index-merge

Three tables: product: with columns: ( a, g, ...a_lot_more... ) a: PK, clustered g: bit-column main: with columns: ( c, f, a, b, ...a_lot_more... ) c: PK, clustered f: bit-column (a, b): UQ ...
2
votes
1answer
5k views

How to handle temporary tables with mutliple connections?

In Is there a way to hint to query optimizer to MySQL which constraints should be done first? I created a subquery. The subquery is often not optimized. I think a better way is to create a temporary ...
2
votes
2answers
2k views

how to avoid duplicated column in two different tables?

OK, I'm inexperienced in terms of database design, so hopefully my question isn't too silly. I have 2 tables users and user_profiles these two tables has one-to-one relation between them. so(...
2
votes
1answer
17k views

How to import Timestamp from a CSV file

I am trying to Import a CSV file with a column called timestamp to MySQl to a column with the structure timestamp but all i get are NULLS in the columns is there a way that i can import the timestamp ...

1
363 364
365
366 367
399