大约有 6,100 项符合查询结果（耗时：0.0207秒） [XML]
MYSQL OR vs IN performance
...s the same.
$t = microtime(true);
for($i=0; $i<10000; $i++):
$q = DB::table('users')->where('id',1)
->orWhere('id',2)
->orWhere('id',3)
->orWhere('id',4)
->orWhere('id',5)
->orWhere('id',6)
->orWhere('id',7)
->orWhere('id',8)
->orWhere(...
How to find the statistical mode?
... hope it's helpful. It is also what I was thinking anyways. You'll want to table() the data, sort and then pick the first name. It's hackish but should work.
names(sort(-table(x)))[1]
share
|
impr...
Why should I capitalize my SQL keywords? [duplicate]
...nk the latter is more readable. You can easily separate the keywords from table and column names, etc.
share
|
improve this answer
|
follow
|
...
How can I get a list of all functions stored in the database of a particular schema in PostgreSQL?
...
After some searching, I was able to find the information_schema.routines table and the information_schema.parameters tables. Using those, one can construct a query for this purpose. LEFT JOIN, instead of JOIN, is necessary to retrieve functions without parameters.
SELECT routines.routine_name, pa...
How to implement a unique index on two columns in rails
I have a table and I'm trying to add a unique index on two columns. Those columns are also indexed. So my question is if I just can remove the indexes who were just for one column or if I have to use all three indexes:
...
Why is the Fibonacci series used in agile planning poker? [closed]
...nd verbal description in the software domain is closer to the one shown in Table 3 than to Saaty’s." And in this table we see that something is called "slightly bigger" if it is 125% of the base size and it is called "bigger", if it is 175% of the base size.
– asmaier
...
What is the difference between a database and a data warehouse?
... as Data Warehousing. This records the data from the user for history.
The tables and joins are complex since they are normalized (for RDMS). This is done to reduce redundant data and to save storage space.
Entity – Relational modeling techniques are used for RDMS database design.
Optimized for wr...
source of historical stock data [closed]
...n reverse engineer the following example:
http://ichart.finance.yahoo.com/table.csv?s=YHOO&d=0&e=28&f=2010&g=d&a=3&b=12&c=1996&ignore=.csv
Essentially:
sn = TICKER
a = fromMonth-1
b = fromDay (two digits)
c = fromYear
d = toMonth-1
e = toDay (two digits)
f = toYear...
Design Pattern for Undo Engine
...e object is needed, you lookup the current definition of the object from a table. The table contains a linked list for each object that contains all the previous versions, along with information regarding which checkpoint they were active for.
Implementing undo/redo is simple: Do your action and es...
Dynamic SELECT TOP @var In SQL Server
...
SELECT TOP (@count) * FROM SomeTable
This will only work with SQL 2005+
share
|
improve this answer
|
follow
|
...