大约有 44,000 项符合查询结果（耗时：0.0520秒） [XML]
How to find Unused Amazon EC2 Security groups
...can't easily (might not even be possible) to delete active security groups if you miss one associated w/another service.
Using the newer AWS CLI tool, I found an easy way to get what I need:
First, get a list of all security groups
aws ec2 describe-security-groups --query 'SecurityGroups[*].GroupId'...
mongoDB/mongoose: unique if not null
I was wondering if there is way to force a unique collection entry but only if entry is not null .
e
Sample schema:
4 Answ...
Assertion failure in dequeueReusableCellWithIdentifier:forIndexPath:
...
You're using the dequeueReusableCellWithIdentifier:forIndexPath: method. The documentation for that method says this:
Important: You must register a class or nib file using the registerNib:forCellReuseIdentifier: or registerClass:forCellReuseIdentifier: method befo...
How do I put an 'if clause' in an SQL string?
...
For your specific query, you can do:
UPDATE purchaseOrder
SET purchaseOrder_status = 'COMPLETED'
WHERE purchaseOrder_ID = '@purchaseOrder_ID' and
not exists (SELECT *
FROM itemsOrdered WHERE purcha...
Are the shift operators () arithmetic or logical in C?
In C, are the shift operators ( << , >> ) arithmetic or logical?
11 Answers
...
How can I stop a Postgres script when it encounters an error?
Is there a way to specify that when executing a sql script it stops when encountering the first error on the script, it usually continues, regardless of previous errors.
...
What are static factory methods?
...o we use a static factory method getDbConnection that creates a connection if we're below the limit. Otherwise, it tries to provide a "spare" connection, failing with an exception if there are none.
public class DbConnection{
private static final int MAX_CONNS = 100;
private static int total...
Why does a function with no parameters (compared to the actual function definition) compile?
...at the function returns. This can not be an array type or a function type. If not given, then int
is assumed.
function-name is the name of the function.
parameter-list is the list of parameters that the function takes separated by commas. If no parameters are given, then the function
d...
Use of “global” keyword in Python
...e documentation is that Python has a separate namespace for functions, and if I want to use a global variable in that function, I need to use global .
...
JavaScript :How to set a Conditional Break Point in Chrome debugger tools
...hat breakpoint. Type an expression and the breakpoint will only pause only if the condition is true.
share
|
improve this answer
|
follow
|
...