I am using MySQL and currently have 3 tables in a database. I created a view table with relationships between the 3 tables. The view table should be about 200 000 rows of data because i also tested the same query in Access and it works fine, but unfortunately i am not allowed to use Access.
When i build the view in MySQL i get a message that says the view was build successfully. But when i try to actually view the data, it gives me something like, MySQL ran out of memory. I am not sure what i can do differently to avoid this message. Can someone please give some advice?
You can use the Quick option for running your query.
Do not cache each query result, print each row as it is received. This
may slow down the server if the output is suspended. With this option,
mysql does not use the history file.
Related
I have a production database in which I have multiple tables. There is one table in which I store the server responses for the API calls which I receive.
Now that particular table is not working properly. I mean, the data is getting added into that table.
When I click on info button of the table, am getting the details which include number of rows and all. I can see that it's increasing. But the problem is that, whenever I try to execute any query on that table, my MySql workbench crashes.
I tried repair table indoor.ServerResponse; but again this query also doesn't work. It keeps on running and somewhere down the line, it freezes.
I just have few thousand rows in that table.
Now my question is :
1) How do I repair the table ? Did I lose it all?
2) How do I make sure that this doesn't happen in future? As this is the prod database.
3) I am also not able to Alter other tables in the database. But the queries run fine. Why is it so?
P.S. Am using MySql workbench.
I am using MySQL Query Browser 1.2.17. My problem is that using EXACTLY the same query sometimes I get No database selected error.
I tried to find any dependence in using USE database; or FROM database.table.
I have no idea when will I get an error and when I won't and if I get I don't know how to solve this (since there is in the query USE database;).
UPDATE AND SOLUTION:
Since the problem was independent neither on the USE database; nor FROM database.table and has been observed RANDOMLY (ex. run query, it works, then immediately run again with the same query and it didn't work anymore), I recreated the database simply filling it with data from backup and it helped.
Best practice to write query.
databasename.tablename
example
SELECT * FROM database.table where 1 = 1
I'm a java dev who uses Mysql Workbench as a database client and IntelliJ IDEA as an IDE. Every day I do SQL queries to the database from 5 up to 50 times a day.
Is there a convenient way to save and re-run frequently used queries in Mysql Workbench/IntelliJ IDEA so that I can:
avoid typing a full query which has already been used again
smoothly access a list of queries I've already used (e.g by auto-completion)
If there is no way to do it using Mysql Workbench / IDEA, could you please advise any good tools providing this functionality?
Thanks!
Create Stored Procedures, one per query (or sequence of queries). Give them short names (to avoid needing auto-completion).
For example, to find out how many rows in table foo (SELECT COUNT(*) FROM foo;).
One-time setup:
DELIMITER //
CREATE PROCEDURE foo_ct
BEGIN;
SELECT COUNT(*) FROM foo;
END //
DELIMITER ;
Usage:
CALL foo_ct();
You can pass arguments in in order to make minor variations. Passing in a table name is somewhat complex, but numbers of dates, etc, are practical and probably easy.
If you have installed SQLyog for your mysql then you can use Favorites menu option in which you can save your query and in one click it will automatically writes the saved query on Query Editor.
The previous answers are correct - depending on the version of the Query Browser they are either called Favorites or Snippets - the problem being you can't create sub-folders to group them. And keeping tabs open is an option - but sometimes the browser 'dies' - and you're back to ground 0. So the obvious solution I came up with - create a database table! I have a few 'metadata' fields for descriptions - the project a query is associated to; problem the query solves; and the actual query.
You could keep your query library in an SQL file and load that when WB opens (it's automatically opened when you restart WB and that file was open on last close). When you want to run a specific query place the caret in it's text and press Ctrl+Enter (Cmd+Enter on Mac) to run only this query. The organization of that SQL file is totally up to you. You have more freedom than any "favorites" solution can give you. You can even have more than one file with grouped statements.
Additionally, MySQL Workbench has a query history (see the Output Tab), which is saved to disk, so you can return to a query even month's after you wrote it.
I am having a weird problem with mysql. I am developing a visual application on C# that stores data into a database. Previously I used SQL for the Database, but my client changed his mind for mysql. So I recreated the same schema on mysql. Now it is happening a really odd thing: My tables are completely empty, but when I execute the views, they return me back data from the old SQL tables, when I read directly from the tables they appear empty. The user that I use to connect are different and the most strange thing is that it happens even when I execute the view on mysql workbench. I have even truncated the tables in mysql and still the same thing. Does anybody know what may cause this anomaly and how to solve it?
p.s. Workbench version 6.2; Sql version SQL SERVER 2014
Regards.
In MySQL, a view is a virtual table based on the result-set of an SQL statement.
It contains rows and columns, just like a real table in your database. The fields in a view are fields from one or more real tables in the database.
When you execute the views, they return back data from the old SQL tables. It is because your view still contains the data you run a while ago. You have forgotten to Drop your View every time you execute it. To Drop a MySQL view, try this one:
DROP VIEW view_name
Views do NOT contain data of any kind -- except for Materialized Views and MySQL does not have those. If views had to be dropped and recreated every time a DML statement was executed on a table, views would be utterly useless.
The only time a view can return old data is when one process changes the contents of a table used in the view and the view is queried by another process before the first process commits the changes. You have not specified how the tables are being changed and how they are being queried. Nor have you included the create view statement. You could well be using other tables than what you think. This can happen during initial design of a database if tables are being slapped around like mad.
Am trying to import some selective data and create a table in MS Access db 2002 from a linked table. For some odd reason the performance became really bad all of a sudden when importing the data.
I tried googleing and tried various methods like reparing/compacting the db, Changing the SubDataSheet Name to [None] from [Auto] but either one worked.
Can any one please give me some examples to increase the performance of linked tables.
Thank you.
Rather than selecting information from a linked table and trying to make a local table, when using a database server like MS MSQL, you would be better to create a "Pass Through Query" to do the select work on the server side, and then carry out a simple select * on this pass through to get your data in to a local table. This will give the best results if your first select statement is complex and takes a while for Access to run on a linked table, if that is not the issue then you will need to look at your network speed which connects you to your MS SQL server.