Planet MySQL Planet MySQL: Meta Deutsch Español Français Italiano 日本語 Русский Português 中文
10 Newer Entries Showing entries 31 to 40 of 1030 10 Older Entries

Displaying posts with tag: sql (reset)

How to use and get output arguments in stored procedure using OUT parameter mode?
+1 Vote Up -0Vote Down

It is sometimes required to get the result of a stored procedure in a variable which can be used later or to output the result.

To do so, we can use the "OUT" parameter mode while defining stored procedures.

In the below section, we will be writing a stored procedure to get the square root of a number returned in an output variable provided by us.

Stored Procedure Definition:

Store the below stored procedure in a file named …

  [Read more...]
We’re Hiring! And Looking to Add More 9s to the Severalnines Team!
+1 Vote Up -0Vote Down

August 15, 2014 By Severalnines



We're looking for an energetic and talented web developer to join our small but agile web team. This position is full-time and pay is negotiable. The hours are flexible and work can be done remotely.


Severalnines is a self-funded startup with a dozen employees; headquartered in Stockholm, Sweden and with a globally distributed, home-office based team. We provide automation and management software for database clusters. Our …

  [Read more...]
Which Compression Tool Should I Use for my Database Backups? (Part I: Compression)
+0 Vote Up -0Vote Down

This week we are talking about size, which is a subject that should matter to any system administrator in charge of the backup system of any project, and in particular database backups.

I sometimes get questions about what should be the best compression tool to apply during a particular backup system: gzip? bzip2? any other?

The testing environment

In order to test several formats and tools, I created a .csv file (comma-separated values) that was 3,700,635,579 bytes in size by transforming a recent dump of all the OpenStreetMap nodes …

  [Read more...]
Handling Error Messages and Warnings with MySQL
Employee_Team +1 Vote Up -0Vote Down

To ensure that your MySQL Database works as efficiently as possible, it is important to know how to handle error messages and warnings.

Error messages have three components:

  • A MySQL-specific error code, such as 1146
  • A SQLSTATE error code. These codes are defined by standard SQL and the ODBC standard.
  • A text message that describes the problem

MySQL Server generates a warning when it is not fully able to comply with a request or when an action has possibly unintended side effects. You can display these warnings with the SHOW WARNINGS statement.

To learn about handling error …

  [Read more...]
MariaDB and Stored Procedures: errata & repository
+1 Vote Up -0Vote Down

In the article How MariaDB makes Stored Procedures usable I explained how to use the MariaDB CONNECT Storage Engine to workaround Stored Procedures limitations. Please read that article, if you didn’t, for details.

Since the technique to workaround such limitations is verbose and error-proof, I also proposed a procedure which makes it easy and convenient. Even thought this is a simple …

  [Read more...]
How MariaDB makes Stored Procedures usable
+4 Vote Up -0Vote Down

I already wrote how MariaDB makes the debug of stored procedures much easier via the SQL Error Log. But I recently found out that MariaDB provides a usable workaround for some big limitations of their procedural SQL.

First, SELECT is not the only SQL statement which returns a resultset. Other examples are DELETE RETURNING, CALL, SHOW, …

  [Read more...]
Debugging MariaDB stored procedures with the SQL Error Log
+1 Vote Up -0Vote Down

A very old version of the MySQL site contained a nice header: Speed, Power, Ease of Use. I don’t think that stored programs (routines, triggers, events) were supported, at that time. Now they are, and… developing them is amazingly hard.

There are many problems, for example the language is not flexible and the execution is sloooow. But the biggest problem is that there is no debug API.

In details, one of the biggest problems is that, if you have complex procedures (accessing multiple tables, having error …

  [Read more...]
On PostgreSQL. Interview with Bruce Momjian.
+0 Vote Up -0Vote Down

“There are four things that motivate open source development teams:
1. The challenge/puzzle of programming, 2. Need for the software, 3. Personal advancement, 4. Belief in open source”
— Bruce Momjian.

On PostgreSQL and the challenges of motivating and managing open source teams, I have interviewed Bruce Momjian, Senior Database Architect at EnterpriseDB, and Co-founder of the PostgreSQL Global Development Group and Core …

  [Read more...]
MySQL Insert from Query
+0 Vote Up -1Vote Down

While working with an error that my students surfaced in the Oracle Database 12c, I blogged about the limit of using a subquery in an Oracle INSERT statement, and I discovered something when retesting it in MySQL. It was a different limitation. I was also surprised when I didn’t find any mention of it through a Google search, but then I may just not have the right keywords.

The original test case uses a subquery to create a multiple row result set for an INSERT statement. Unfortunately, I discovered that you can’t …

  [Read more...]
How to execute mysql query from a file in your mysql client terminal?
+0 Vote Up -0Vote Down

Being a terminal fan myself, I usually find myself running queries in the mysql client instead of a UI interface as it is much faster. You get to see the results instantaneously.

One thing which is pretty tedious is editing a big query again after once running it as the whole multi-line formatted query now appears on a single line, thus reducing its readability.

But no problems, you can edit your query from a file and run the file from your mysql client terminal as many times as you want with as many edits.

To do so, follow the below steps:

1. Open your terminal and cd into the …

  [Read more...]
10 Newer Entries Showing entries 31 to 40 of 1030 10 Older Entries

Planet MySQL © 1995, 2015, Oracle Corporation and/or its affiliates   Legal Policies | Your Privacy Rights | Terms of Use

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.