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How to add column if not exists on PostgreSQL?
...statement:
DO $$
BEGIN
BEGIN
ALTER TABLE <table_name> ADD COLUMN <column_name> <column_type>;
EXCEPTION
WHEN duplicate_column THEN RAISE NOTICE 'column <column_name> already exists in <table_name>.';
END;
END;
$$
...
PHP mail function doesn't complete sending of e-mail
... one you need to run through the checklist below to find any potential pitfalls you may be encountering.
Make sure error reporting is enabled and set to report all errors
Error reporting is essential to rooting out bugs in your code and general errors that PHP encounters. Error reporting needs to ...
Can you do a partial checkout with Subversion?
...ight find useful. From the documentation:
... sparse directories (or shallow checkouts) ... allows you to easily check out a working copy—or a portion of a working copy—more shallowly than full recursion, with the freedom to bring in previously ignored files and subdirectories at a later tim...
List all base classes in a hierarchy of given class?
...ass Foo (whether it is a new-style class or not), how do you generate all the base classes - anywhere in the inheritance hierarchy - it issubclass of?
...
Find out how much memory is being used by an object in Python [duplicate]
...and internal structures related to object types and garbage collection. Finally, some python objects have non-obvious behaviors. For instance, lists reserve space for more objects than they have, most of the time; dicts are even more complicated since they can operate in different ways (they have a ...
Unable to verify leaf signature
...
Note: the following is dangerous, and will allow API content to be intercepted and modified between the client and the server.
This also worked
process.env['NODE_TLS_REJECT_UNAUTHORIZED'] = '0';
...
What is your single most favorite command-line trick using Bash? [closed]
We all know how to use <ctrl>-R to reverse search through history, but did you know you can use <ctrl>-S to forward search if you set stty stop "" ? Also, have you ever tried running bind -p to see all of your keyboard shortcuts listed? There are over 455 on Mac OS X by default. ...
Getting LaTeX into R Plots
...t interferes with the ggplot ~ # tikzDecice combo
colnames(AR) <- c("$V_{BB}[V]$", "$V_{RB}[V]$" , "$V_{RC}[V]$" , "$I_B[\\mu A]$" , "IC" , "$V_{BE}[V]$" , "$V_{CE}[V]$" , "beta" , "$I_E[mA]$")
# make sure the working directory is where you want your tikz file to go
setwd("~/TexImageFolder/")
...
convert_tz returns null
...ving these files to a different location such as /usr/share/zoneinfo/.bak/ allows for the command
mysql_tzinfo_to_sql /usr/share/zoneinfo | mysql -u root -p mysql
to fully populate all of the expected timezone information.
This may or may not be a bug in my installed version of MySQL:
$ mysql -...
File Upload ASP.NET MVC 3.0
...maxRequestLength="x" /> in your web.config, where x is the number of KB allowed for upload.
– rsbarro
May 22 '11 at 20:33
86
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