大约有 37,000 项符合查询结果（耗时：0.0305秒） [XML]
In SQL, what's the difference between count(column) and count(*)?
...column) does not
[edit] added this code so that people can run it
create table #bla(id int,id2 int)
insert #bla values(null,null)
insert #bla values(1,null)
insert #bla values(null,1)
insert #bla values(1,null)
insert #bla values(null,1)
insert #bla values(1,null)
insert #bla values(null,null)
se...
Should MySQL have its timezone set to UTC?
...`timestamp_field`, @@session.time_zone, '+00:00') AS `utc_datetime`
FROM `table_name`
You can also set the sever or global or current session timezone to UTC and then select the timestamp like so:
SELECT `timestamp_field` FROM `table_name`
To select the current datetime in UTC:
SELECT UTC_TIM...
T-SQL split string
...CTION dbo.splitstring ( @stringToSplit VARCHAR(MAX) )
RETURNS
@returnList TABLE ([Name] [nvarchar] (500))
AS
BEGIN
DECLARE @name NVARCHAR(255)
DECLARE @pos INT
WHILE CHARINDEX(',', @stringToSplit) > 0
BEGIN
SELECT @pos = CHARINDEX(',', @stringToSplit)
SELECT @name = SUBSTRING(@strin...
What are best practices for multi-language database design? [closed]
...hat is the best way to create multi-language database? To create localized table for every table is making design and querying complex, in other case to add column for each language is simple but not dynamic, please help me to understand what is the best choose for enterprise applications
...
Using R to download zipped data file, extract, and import data
...oad.file("http://www.newcl.org/data/zipfiles/a1.zip",temp)
data <- read.table(unz(temp, "a1.dat"))
unlink(temp)
Compressed (.z) or gzipped (.gz) or bzip2ed (.bz2) files are just the file and those you can read directly from a connection. So get the data provider to use that instead :)
...
Why do you create a View in a database?
...ews can hide complexity
If you have a query that requires joining several tables, or has complex logic or calculations, you can code all that logic into a view, then select from the view just like you would a table.
2. Views can be used as a security mechanism
A view can select certain columns an...
SQL statement to get column type
Is there a SQL statement that can return the type of a column in a table?
22 Answers
2...
How do exceptions work (behind the scenes) in c++
...atching_functionv, .-_Z20my_catching_functionv
.section .gcc_except_table,"a",@progbits
.align 4
.LLSDA9:
.byte 0xff
.byte 0x0
.uleb128 .LLSDATT9-.LLSDATTD9
.LLSDATTD9:
.byte 0x1
.uleb128 .LLSDACSE9-.LLSDACSB9
.LLSDACSB9:
.uleb128 .LEHB0-.LFB9
.uleb128 .L...
Check if a row exists, otherwise insert
I need to write a T-SQL stored procedure that updates a row in a table. If the row doesn't exist, insert it. All this steps wrapped by a transaction.
...
Sequelize Unknown column '*.createdAt' in 'field list'
...he error is that you have timestamps enabled in sequelize, but your actual table definitions in the DB do not contain a timestamp column.
When you do user.find it will just do SELECT user.*, which only takes the columns you actually have. But when you join, each column of the joined table will be a...