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'IF' in 'SELECT' statement - choose output value based on column values
...t
when report_type = 'N'
then -amount
else null
end
from table
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Versioning SQL Server database
...N to N+1. (These go in your version control system.) A _version_history_ table, something like
create table VersionHistory (
Version int primary key,
UpgradeStart datetime not null,
UpgradeEnd datetime
);
gets a new entry every time an upgrade script runs which corresponds to th...
What is the best way to solve an Objective-C namespace collision?
...not changing the address of the original symbol. Objective-C uses a lookup table to map class names to addresses, and it's a 1-1 mapping, so you can't have two classes with the same name. Thus, to load both classes, one of them must have their name changed. However, when other classes need to access...
How can I sanitize user input with PHP?
...o be guaranteed against SQL injection.
Please see my website http://bobby-tables.com/ for more about preventing SQL injection.
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SQL order string as number
... cast your column value to an integer explicitly with
select col from yourtable
order by cast(col as unsigned)
or implicitly for instance with a mathematical operation which forces a conversion to number
select col from yourtable
order by col + 0
BTW MySQL converts strings from left to right....
Differences between Perl and PHP [closed]
...han @foo or %foo.
(related to the previous point) Perl has separate symbol table entries for scalars, arrays, hashes, code, file/directory handles and formats. Each has its own namespace.
Perl gives access to the symbol table, though manipulating it isn't for the faint of heart. In PHP, symbol table...
What is the right way to override a setter method in Ruby on Rails?
...iginal Answer
If you want to override the setter methods for columns of a table while accessing through models, this is the way to do it.
class Model < ActiveRecord::Base
attr_accessible :attribute_name
def attribute_name=(value)
# custom actions
###
write_attribute(:attribute_...
How to use Oracle ORDER BY and ROWNUM correctly?
...ory, in Oracle, you need to limit the results manually when you have large tables and/or tables with same column names (and you don't want to explicit type them all out and rename them all). Easy solution is to figure out your breakpoint and limit that in your query. Or you could also do this in the...
Count number of records returned by group by
... count(*) RecordsPerGroup,
COUNT(*) OVER () AS TotalRecords
from temptable
group by column_1, column_2, column_3, column_4
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Create new user in MySQL and give it full access to one database
... - This is the command used to create users and grant rights to databases, tables, etc.
ALL PRIVILEGES - This tells it the user will have all standard privileges. This does not include the privilege to use the GRANT command however.
dbtest.* - This instructions MySQL to apply these rights for use ...