Category: Computers

All things computing.

Figuring out MySQL ERROR 1005 (HY000) Can’t create table (errno: 150)

Posted on by rchapin

So I’m dumping a database on a remote server to pull down to my local box to do some development.  When loading the mysqldump file I encountered the error:

ERROR 1005 (HY000) at line 8680: Can't create table 'database.table' (errno: 150)

After doing some searching online it seems that is one of the notoriously cryptic MySQL error messages that is woefully overloaded.

I did manage to fix the error (which ended up being a foreign key reference from another table to the one that was erroring out whereby the column definitions were not exactly the same) and learned two important things:

  1. You can invoke the following mysql command immediately after the error to get a more verbose error message (which is what enabled me to solve the problem): SHOW INNODB STATUS
  2. Jason Hinkle has a very nice online reference with a number of possible culprits, and their solutions are listed.

Install Android Application Directly Without it Being in the Market

Posted on by rchapin

When developing apps you will not only want to test them against the Eclipse AVDs but also install them on an actual device.

To do so, set up an HTTP server (here is a link to another article on how to set up a quick and dirty HTTP server) and put you .apk file somewhere where you can get to it from your local network.

Make sure that you check the ‘Unknown sources’ setting that will enable you to install applications that are of non-Market origin. 

Then just open a browser on your Android device and download the .apk file.  Once done, when you attempt to open the .apk file the device will ask you if you want to install it.

Deleting Safari Cookies in iOS Simulator

Posted on by rchapin

If you are doing any kind of development that involves cookies and need to be able to delete them while testing iOS you will likely need to delete them as well.

The iOS simulator (Launched from Xcode by going to Xcode > Open Developer Tool > iOS Simulator) stores data for the simulator in the following directory on the host Mac OSX file system:  /Users/<uid>/Library/Application Support/iPhone Simulator/

First, quit out of the iOS Simulator.

To find the cookies and delete them open up a terminal and cd to the iPhone Simulator directory.

$ cd /Users/<uid>/Library/Application\ Support/iPhone\ Simulator/

Then execute the following find command to find the cookie data file:

$ find ./ -type f -iname ‘*binarycookies*’ -exec ls -l {} \;
-rw-r–r–  1 ryanchapin  staff  2503 Nov  6 08:32 .//7.0-64/Applications/630F9FE9-87B2-4A6D-8C60-CA70EBC5FD8A/Library/Cookies/Cookies.binarycookies

You can then update the find command to the following to delete the file.

$ find ./ -type f -iname ‘*binarycookies*’ -exec rm {} \;

Executing MySQL Queries and Commands from the Command Line to a Remote Server

Posted on by rchapin

Following are a couple of ways to execute SQL on a remote MySQL server via the shell.

Executing SQL directly from the command line:

$ mysql -u uid -p -h remote.host database -e ‘SQL query here;’

Executing SQL from a file on the local host on the remote server:

$ mysql -u uid -p -h remote.host database < file.sql

You can also connect to the remote mysql server and from the command line execute SQL from files on the local drive as such (as long as the file is in the same directory from which the mysql connection is made

mysql> \. file.sql

Notice NO ‘;’ at the end of the command.

Moreover, you can use the following to run commands in your local shell

mysql> \! ls

Will give you the directly listing of the dir from which you invoked the mysql remote connection.

mysql > \! vi file.sql

Will allow you to edit the file on your local drive without having to close the mysql cli.

Executing Dynamically Generated SQL Queries from a Shell Script

Posted on by rchapin

Following is how to generate dynamic SQL in a shell script and then execute those queries.

Let’s say, for instance, that you have a list of tables that you want to flush regularly during development and don’t want to type in the SQL queries each time.  Moreover, you just want to maintain a list of the table names and add and remove from it when necessary and have your script dynamically generate and execute the delete statements.

For the purposes of this tutorial we are running these commands as root to avoid the additional complication of authentication.

The first thing you need is your text file with the list of your tables:

table_list.txt:

table_a
table_b
table_c

delete_data.sh:

table_list.txt:

table_a
table_b
table_c

delete_data.sh:

#!/bin/bash

for i in `cat tables_list.txt`
do

   mysql -u root dbase_name << END_SQL
   delete from ${i};
END_SQL
#
# It is imperitive that the END_SQL redirect identifier
# be on its own line without any leading or trailing spaces
#

done

The script will run, will make a connection to MySQL and then execute the command with the dynamically generated target table.

This will work with other databases other than MySQL as well.

Send a Text Message To Your Cell Phone From E-mail

Posted on by rchapin

This might be old news but I came accross this today and wanted to make a note of it for myself for future reference.

All that you need to do is address the message to the phone number @ the service prodivers designated domain that they use to convert and forward the message content to your mobile device.

What I see interesting in this is being able to send txt messages from a system or service that encounters an error that requires human intervention.

For example, if you want to send a message to someone on a Verizon phone, you would address the e-mail to:

5551230987@vtext.com

Send your message as normal, and they will get it as a SMS.

All of the providers follow the schema of the 10-digit phone number followed by the @ and then the domain for the provider.

Following is a list of the domains used by the major providers.  If you don’t see your provider in the list the search string I used to find each was “send a text message to a cell phone from email [name-of-provider]”

  • Alltel: @message.alltel.com
  • AT&T: @txt.att.net.  To send multimedia messages use @mms.att.net
  • Bell Canada: @txt.bellmobility.ca
  • Boost Mobile: myboostmobile.com
  • Cricket Wireless: @sms.mycricket.com.  To send multimedia messages use @mms.mycricket.com
  • Metro PCS: @mymetropcs.com or @metropcs.sms.us
  • Qwest: @qwestmp.com
  • Sprint: @messaging.sprintpcs.com
  • T-Mobile: @tmomail.net
  • U.S. Cellular: @email.uscc.net
  • Verizon: @vtext.com
  • Virgin Mobile USA: @vmobl.com

Setting Up Android SDK and Plugin in an Existing Install of Eclipse

Posted on by rchapin

To set up an existing install of Eclipse to do some Android development do the following:

  • Go to http://developer.android.com/sdk/index.html and look for and download the ADT bundle for your OS (in my case I was using Fedora Core 18 at the time)
  • Unpack it as the user that is going to be running Eclipse and/or after you unpack it make sure that your user has read/write/execute permissons for the files in this directory (obviously, you don’t need execute permssion for non executables).  To make things easy, I just created an ~/sdks directory and unpacked it in there.
  • Fire up eclipse and go to Help/New Software.
  • Add the following repository: https://dl-ssl.google.com/android/eclipse/
  • Check off both the Developer Tools and NDK Plugins.
  • After those plugins install go to Window/Preferences/Android, and click the ‘Browse’ button next to ‘SDK Location:’, selecting the /path-to/adt-bundle-linux-x86_64-20130917/sdk.  When setting this up you might get a dialogue box that indicates that the version of the Android SDK Tools and/or Android SDK Platform Tools is not compatible with the version of the adt-bundle you are attempting to use.  In my case, I was prompted to update it via the Android SDK Manager and was able to download an updated version.

If you have an existing project that you are working with you might have to update the project.properties to update the sdk level number.

You might see an error like:

Unable to resolve target ‘android-17’ until the SDK is loaded

If so, update the ‘target=android-17’ property in the project.properties file to match the value of ‘Platform.MinPlatformToolsRev’ in the /path-to/adt-bundle-linux-x86_64-20130917/sdk/tools/source.properties file.

In my case, I updated the project.properties to:

# Project target.
target=android-18

Getting the value ’18’ from the source.properties:

Platform.MinPlatformToolsRev=18

Showing Hidden Files and Folders Under Mac OSX

Posted on by rchapin

By default the Mac hides a number of different Folder as well as any file or folder that starts with a “.” character.

To show all of these files/folders in the Finder open a terminal and enter teh following commands:

$ defaults write com.apple.Finder AppleShowAllFiles TRUE

$ killall Finder

The Finder should restart and you should be able to see all of the files and folders on the machine.

Do Not Use Symlinks in Jetty’s webapps Directory

Posted on by rchapin

I set up a development instance of Jetty on my local machine and have been happily coding, compiling and deploying via a shell script.  The script copies the war from my user’s target directory to the jetty users’s home dir changes the permissions and then moves it to the /webapp dir creating a symlink to the name of the .war that is referenced in a number of config files.

This was working just fine until I did a merge with another developers code and a significant portion of it changed that Jetty had problems determining whether or not is should dump it’s local cache of .class files and configs and got into a very funky state.  Unfortunately, not one in which it was obviously funky, but where, all of the sudden I could not look up defined DataSources in JNDI.

Ultimately, after looking through many other different things, I decided to delete the symlink and, rename the .war in the /webapps dir.

Bingo, worked right away.

© 2005 Ryan Chapin