大约有 30,000 项符合查询结果（耗时：0.0456秒） [XML]
Primary key or Unique index?
...t SQL Server only allows one null value though.
– David Aldridge
Aug 30 '13 at 14:22
3
but still ...
Java, List only subdirectories from a directory, not files
...lass to list the directories.
File file = new File("/path/to/directory");
String[] directories = file.list(new FilenameFilter() {
@Override
public boolean accept(File current, String name) {
return new File(current, name).isDirectory();
}
});
System.out.println(Arrays.toString(directories...
Postgres: INSERT if does not exist already
...amples. (1) INSERT if not exists else NOTHING - INSERT INTO distributors (did, dname) VALUES (7, 'Redline GmbH') ON CONFLICT (did) DO NOTHING; (2) INSERT if not exists else UPDATE - INSERT INTO distributors (did, dname) VALUES (5, 'Gizmo Transglobal'), (6, 'Associated Computing, Inc') ON CON...
Where can I find the IIS logs?
... local IIS. I've created a website exactly as explained in their install guide, but am having some problems, and would like to see what the IIS log has to say. Embarrassingly enough, the problem is I can't find the log files!
...
How to make input type= file Should accept only pdf and xls
...nspector. So in either case you need to check the file type on the server side (your second question).
Example:
<input type="file" name="upload" accept="application/pdf,application/vnd.ms-excel" />
To your third question "And when I click the files (PDF/XLS) on webpage it automatically sho...
What's the difference between belongs_to and has_one?
...
They essentially do the same thing, the only difference is what side of the relationship you are on. If a User has a Profile, then in the User class you'd have has_one :profile and in the Profile class you'd have belongs_to :user. To determine who "has" the other object, look at where the ...
Are there any CSV readers/writer libraries in C#? [closed]
... @Zimano Not true. You can read individual fields or even just get a string array for the row. Check out the documentation. joshclose.github.io/CsvHelper
– Josh Close
Oct 4 '19 at 15:55
...
Programmatically shut down Spring Boot application
...means closing the underlying ApplicationContext. The SpringApplication#run(String...) method gives you that ApplicationContext as a ConfigurableApplicationContext. You can then close() it yourself.
For example,
@SpringBootApplication
public class Example {
public static void main(String[] arg...
Parsing CSV files in C#, with header
...rs(",");
while (!parser.EndOfData)
{
//Process row
string[] fields = parser.ReadFields();
foreach (string field in fields)
{
//TODO: Process field
}
}
}
The docs are here - TextFieldParser Class
P.S. If you need a CSV exporter, try C...
How do the PHP equality (== double equals) and identity (=== triple equals) comparison operators dif
...verting to boolean
Converting to integer
Converting to float
Converting to string
Converting to array
Converting to object
Converting to resource
Converting to NULL
Type comparison table
As reference and example you can see the comparison table in the manual:
Loose comparisons with ==
┌─...