大约有 37,000 项符合查询结果（耗时：0.0173秒） [XML]
Building a notification system [closed]
...this topic is already quite old, however i'm a bit puzzled about the first table, what excactly is the purpose of this table? what is the advantage of having this as a separate table versus putting the userID in the notification_object table? In other words when will you create a new entry in notifi...
Laravel Eloquent: How to get only certain columns from joined tables
I have got 2 joined tables in Eloquent namely themes and users.
15 Answers
15
...
Insert picture/table in R Markdown [closed]
So I want to insert a table AND a picture into R Markdown. In regular word document I can just easily insert a table (5 rows by 2 columns), and for the picture just copy and paste.
...
What is the optimal length for user password salt? [closed]
...ices for how long the salt should be? I'll be storing the salt in my user table, so I would like the best tradeoff between storage size and security. Is a random 10 character salt enough? Or do I need something longer?
...
How to get cumulative sum
...
@Franklin Only cost efficient for small tables. Cost grows proportional to the square of the number of rows. SQL Server 2012 allows this to be done much more efficiently.
– Martin Smith
May 18 '13 at 19:57
...
Laravel Eloquent groupBy() AND also return count of each group
I have a table that contains, amongst other columns, a column of browser versions. And I simply want to know from the record-set, how many of each type of browser there are. So, I need to end up with something like this: Total Records: 10; Internet Explorer 8: 2; Chrome 25: 4; Firefox 20: 4. (All ad...
Return rows in random order [duplicate]
Is it possible to write SQL query that returns table rows in random order every time the query run?
6 Answers
...
Is there a way to view past mysql queries with phpmyadmin?
I'm trying to track down a bug that's deleting rows in a mysql table.
13 Answers
13...
Quick Way to Implement Dictionary in C
...ection 6.6 of The C Programming Language presents a simple dictionary (hashtable) data structure. I don't think a useful dictionary implementation could get any simpler than this. For your convenience, I reproduce the code here.
struct nlist { /* table entry: */
struct nlist *next; /* next ent...
Fastest Way to Find Distance Between Two Lat/Long Points
...
Create your points using Point values of Geometry data types in MyISAM table. As of Mysql 5.7.5, InnoDB tables now also support SPATIAL indices.
Create a SPATIAL index on these points
Use MBRContains() to find the values:
SELECT *
FROM table
WHERE MBRContains(LineFromText(CONCAT(
...