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Should I commit or rollback a read transaction?
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Suppose I create a temp table, populate it with ids, join it with a data table to select the data that goes with the ids, then delete the temp table. I'm really just reading data, and I don't care what happens to the temp table, since it's temporar...
What is ViewModel in MVC?
...might not be set from the view, it might be auto generated by the Employee table. And DateCreated might also be set in the stored procedure or in the service layer of your application. So Id and DateCreated are not needed in the view model. You might want to display these two properties when you v...
Why isn't SQL ANSI-92 standard better adopted over ANSI-89?
...e one and the USING Clause is another. IMHO, the addition of a column to a table shouldn't break code but a NATURAL JOIN breaks in a most egregious fashion. The "best" way to break is by compilation error. For example if you SELECT * somewhere, the addition of a column could fail to compile. The nex...
Using margin:auto to vertically-align a div
...he three elements have to be nested like so:
.container {
display: table;
height: 100%;
position: absolute;
overflow: hidden;
width: 100%;
}
.helper {
#position: absolute;
#top: 50%;
display: table-cell;
vertical-align: middle;
}
.content {
#position: rela...
How many characters can UTF-8 encode?
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According to this table* UTF-8 should support:
231 = 2,147,483,648 characters
However, RFC 3629 restricted the possible values, so now we're capped at 4 bytes, which gives us
221 = 2,097,152 characters
Note that a good chunk of those chara...
Postgresql: Conditionally unique constraint
... a constraint which enforces uniqueness on a column only in a portion of a table.
2 Answers
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Difference between VARCHAR and TEXT in MySQL [duplicate]
When we create a table in MySQL with a VARCHAR column, we have to set the length for it. But for TEXT type we don't have to provide the length.
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Defeating a Poker Bot
... and patterns (i.e., worst case
scenario is a player who plays 24x7
and 16 tables continuously, there is
a tiny tiny chance this is a real
human. (However some players do have the ability to play very large hand volumes which to the inexperienced eye would appear to be a bot)
Throw it glitches. If ...
jquery live hover
...sing the following jquery code to show a contextual delete button only for table rows we are hovering with our mouse. This works but not for rows that have been added with js/ajax on the fly...
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How to reset db in Django? I get a command 'reset' not found error
...I needed not just to flush the values in the database, but to recreate the tables properly. I'm not using migrations yet (early days) so I really needed to drop all the tables.
Two ways I've found to drop all tables, both require something other than core django.
If you're on Heroku, drop all t...