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Are GUID collisions possible?
...ither unique (for things like version 1 GUIDs), or both unique and unpredictable (for things like version 4 GUIDs). SQL Server's implementation for their NEWID() function appears to use a 128-bit random number, so you're not going to get a collision.
For a 1% chance of collision, you'd need to gen...
Check for column name in a SqlDataReader object
...elp anyone setting their debugger to break on exceptions thrown.
GetSchemaTable() is also another suggestion in many answers. This would not be a preffered way of checking for a field's existance as it is not implemented in all versions (it's abstract and throws NotSupportedException in some versio...
What are the use cases of Graph-based Databases (http://neo4j.org/)? [closed]
...nto the current blub architecture, use a graph database, or CouchDB, or BigTable, or whatever fits your app and you think is cool. It might give you an advantage, and its fun to try new things.
Whatever you chose, try not to build the database engine yourself unless you really like building databas...
Test for non-zero length string in Bash: [ -n “$var” ] or [ “$var” ]
...on that shows more differences between [ (aka test) and [[.
The following table shows that whether a variable is quoted or not, whether you use single or double brackets and whether the variable contains only a space are the things that affect whether using a test with or without -n/-z is suitable ...
How to express a NOT IN query with ActiveRecord/Rails?
...
Using Arel:
topics=Topic.arel_table
Topic.where(topics[:forum_id].not_in(@forum_ids))
or, if preferred:
topics=Topic.arel_table
Topic.where(topics[:forum_id].in(@forum_ids).not)
and since rails 4 on:
topics=Topic.arel_table
Topic.where.not(topics[:f...
How to get record created today by rails activerecord?
...ion suggested in the accepted answer can cause performance issues when the table size grows.
Typically, if you perform lookups based on created_at column, add an index on the table in your migration file.
add_index :posts, :created_at
Now, to lookup records created today:
Rails 3/4
Post.where...
Reset the database (purge all), then seed a database
Is there a rake command to wipe out the data in the database tables?
6 Answers
6
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Is the NOLOCK (Sql Server hint) bad practice?
...dated at the same time another process may be selecting data from the same table. If this happens a lot then there's a high probability of deadlocks unless you use a database mode such as READ COMMITED SNAPSHOT.
I have since changed my perspective on the use of NOLOCK after witnessing how it can i...
In jQuery, how do I get the value of a radio button when they all have the same name?
...dflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<table>
<tr>
<td>Sales Promotion</td>
<td><input type="radio" name="q12_3" value="1">1</td>
<td><input type="radio" name="q12_3" value="2">2</td>
...
Should I use 'border: none' or 'border: 0'?
...they behave in different ways when combined with other rules.
Borders in a table context in collapsing border model
When a table is rendered using border-collapse: collapse, then each rendered border is shared between multiple elements (inner borders are shared among as neighbor cells; outer borders...