大约有 40,000 项符合查询结果（耗时：0.0358秒） [XML]
Use didSelectRowAtIndexPath or prepareForSegue method for UITableView?
I'm using storyboards and I have a UITableView. I have a segue setup that pushes from my table to the detail VC. But which method should I use to handle this? I'll have to pass a couple objects to the detail view. But do I use didSelectRowAtIndex or -(void)prepareForSegue:(UIStoryboardSegue *...
How do I expire a PHP session after 30 minutes?
...>
<html>
<form name="form1" method="post">
<table>
<tr>
<td>Username</td>
<td><input type="text" name="text"></td>
</tr>
<tr>
<td&g...
Summarizing multiple columns with dplyr? [duplicate]
... 2.87
#> 3 3 2.85 2.95 2.95 3.06
Also don't forget about data.table (use keyby to sort sort groups):
library(data.table)
setDT(df)[, lapply(.SD, mean), keyby = grp]
#> grp a b c d
#> 1: 1 3.079412 2.979412 2.979412 2.914706
#> 2: 2 3.029126 3....
How to remove not null constraint in sql server using query
...
ALTER TABLE YourTable ALTER COLUMN YourColumn columnType NULL
share
|
improve this answer
|
follow
...
Why does MYSQL higher LIMIT offset slow the query down?
Scenario in short: A table with more than 16 million records [2GB in size]. The higher LIMIT offset with SELECT, the slower the query becomes, when using ORDER BY *primary_key*
...
In a storyboard, how do I make a custom cell for use with multiple controllers?
...he goal is to have those be re-usable throughout the app (ie, in any of my tableview controllers).
6 Answers
...
What are the applications of binary trees?
...nary Tries - Used in almost every high-bandwidth router for storing router-tables.
Hash Trees - used in p2p programs and specialized image-signatures in which a hash needs to be verified, but the whole file is not available.
Heaps - Used in implementing efficient priority-queues, which in turn are u...
LINQ Join with Multiple Conditions in On Clause
...
This works fine for 2 tables. I have 3 tables and on clause has to link 2 conditions from 3 tables.
My code:
from p in _dbContext.Products
join pv in _dbContext.ProductVariants on p.ProduktId equals pv.ProduktId
join jpr in leftJoinQuery
on new {...
Conversion failed when converting date and/or time from character string while inserting datetime
I was trying to create a table as follows,
15 Answers
15
...
How to encrypt/decrypt data in php?
...
Foreword
Starting with your table definition:
- UserID
- Fname
- Lname
- Email
- Password
- IV
Here are the changes:
The fields Fname, Lname and Email will be encrypted using a symmetric cipher, provided by OpenSSL,
The IV field will store the init...