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Difference between Key, Primary Key, Unique Key and Index in MySQL
...: The columns in which no two rows are similar
Primary Key: Collection of minimum number of columns which can uniquely identify every row in a table (i.e. no two rows are similar in all the columns constituting primary key). There can be more than one primary key in a table. If there exists a uniqu...
In C#, how do I calculate someone's age based on a DateTime type birthday?
...m>
/// <returns>Age in years on a later day. 0 is returned as minimum.</returns>
public static int Age(this DateTime birthDate, DateTime laterDate)
{
int age;
age = laterDate.Year - birthDate.Year;
if (age > 0)
{
age -= Conve...
Saving grid.arrange() plot to file
...
@JackAidley ask a new question, with a minimum self-contained reproducible example, and your sessionInfo() (make sure you have recent versions of R and packages).
– baptiste
Jun 16 '14 at 12:34
...
Retrieve specific commit from a remote Git repository
...changes you don't have. Think in terms of Git making the right thing, with minimum load.
Git stores everything in .git folder. A commit can't be fetched and stored in isolation, it needs all its ancestors. They are interrelated.
To reduce download size you can however ask git to fetch only objec...
Increasing the maximum number of TCP/IP connections in Linux
...ost can create from a particular I.P. address. The fin_timeout defines the minimum time these sockets will stay in TIME_WAIT state (unusable after being used once).
Usual system defaults are:
net.ipv4.ip_local_port_range = 32768 61000
net.ipv4.tcp_fin_timeout = 60
This basically means your sys...
How to check for an undefined or null variable in JavaScript?
...riables (simply returns undefined). Yet these cases should be reduced to a minimum for good reasons, as Alsciende explained.
Note 2
This - even shorter - variant is not equivalent:
if ( !some_variable ) {
// some_variable is either null, undefined, 0, NaN, false, or an empty string
}
so
if (...
SQL Server indexes - ascending or descending, what difference does it make?
...he maximum possible value than in the case when \@myvalue is closed to the minimum possible value.
– Lajos Arpad
Oct 24 '16 at 18:15
...
Incrementing a date in JavaScript
... they wanted to in Date.parse. The new 5th edition specification now has a minimum format that must be accepted, but I wouldn't count on that yet.
– T.J. Crowder
Sep 9 '10 at 8:18
...
How to make Java honor the DNS Caching Timeout?
...to some extend reducing the TTL is fine. (However I dont think 0 is a good minimum and the default of 30s for non-security managers is just fine in most cases).
– eckes
Aug 14 '15 at 16:14
...
How do you get the footer to stay at the bottom of a Web page?
...on of the flex-shrink property, which allows items to shrink more than the minimum height that would be required to display the content.
To fix this issue you will have to set the flex-shrink property explicitly to 0 to the .content and the footer in the above example:
.content {
flex-shrink: 0;
}...