大约有 41,000 项符合查询结果（耗时：0.0463秒） [XML]
Regular expression to limit number of characters to 10
...a regular expression that will only allow lowercase letters and up to 10 characters. What I have so far looks like this:
...
Oracle “(+)” Operator
...dize OUTER joins.
The query would be re-written in ANSI-92 syntax as:
SELECT ...
FROM a
LEFT JOIN b ON b.id = a.id
This link is pretty good at explaining the difference between JOINs.
It should also be noted that even though the (+) works, Oracle recommends not using it:
Oracle re...
Obtaining a powerset of a set in Java
... return this;
}
}
To call it, use this pattern:
Set<Character> set = new TreeSet<Character> ();
for(int i = 0; i < 5; i++)
set.add((char) (i + 'A'));
PowerSet<Character> pset = new PowerSet<Character>(set);
for(Set&l...
How to get current time and date in C++?
...rentDateTime() {
time_t now = time(0);
struct tm tstruct;
char buf[80];
tstruct = *localtime(&now);
// Visit http://en.cppreference.com/w/cpp/chrono/c/strftime
// for more information about date/time format
strftime(buf, sizeof(buf), "%Y-%m-%d.%X", &tst...
CROSS JOIN vs INNER JOIN in SQL
...ame situation.
These 2 examples will return the same result:
Cross join
select * from table1 cross join table2 where table1.id = table2.fk_id
Inner join
select * from table1 join table2 on table1.id = table2.fk_id
Use the last method
...
Select 50 items from list at random to write to file
... leaving the original population unchanged. The resulting list is
in selection order so that all sub-slices will also be valid random
samples. This allows raffle winners (the sample) to be partitioned
into grand prize and second place winners (the subslices).
Members of the popul...
An explicit value for the identity column in table can only be specified when a column list is used
...tead of
SET IDENTITY_INSERT archive_table ON;
INSERT INTO archive_table
SELECT *
FROM source_table;
SET IDENTITY_INSERT archive_table OFF;
you need to write
SET IDENTITY_INSERT archive_table ON;
INSERT INTO archive_table (field1, field2, ...)
SELECT field1, field2, ...
FROM source_table;...
Find value in an array
...
Using Array#select will give you an array of elements that meet the criteria. But if you're looking for a way of getting the element out of the array that meets your criteria, Enumerable#detect would be a better way to go:
array = [1,2,...
Multiple line code example in Javadoc comment
...se of Eclipse, this is because of (bugged?) javadoc utility. If you have @ character in the multiline code inside {@code ...multiline...} then javadoc fails to parse it correctly:( At least this is what I see with Oracle JDK1.7.0_45 javadoc implementation.
– Male
...
What is the equivalent of 'describe table' in SQL Server?
...
use Select * From INFORMATION_SCHEMA.COLUMNS Where TABLE_NAME = 'TABLENAME' if you don't want to use a stored procedure
– Matias Elorriaga
Aug 4 '14 at 18:21
...