大约有 47,000 项符合查询结果（耗时：0.0613秒） [XML]
Checking if a SQL Server login already exists
...
From here
If not Exists (select loginname from master.dbo.syslogins
where name = @loginName and dbname = 'PUBS')
Begin
Select @SqlStatement = 'CREATE LOGIN ' + QUOTENAME(@loginName) + '
FROM WINDOWS WITH DEFAULT_DATABASE=[PUBS], DEFAULT...
How to use GROUP_CONCAT in a CONCAT in MySQL
...
select id, group_concat(`Name` separator ',') as `ColumnName`
from
(
select
id,
concat(`Name`, ':', group_concat(`Value` separator ',')) as `Name`
from mytbl
group by
id,
`Name`
) tbl
group by id;
...
PostgreSQL - fetch the row which has the Max value for a column
...sted index lookup into lives - on my machine
-- the latter query plan was selected given my memory settings and
-- histogram
SELECT
l1.*
FROM
lives AS l1
INNER JOIN (
SELECT
usr_id,
MAX(time_stamp) AS time_stamp_max
FROM
lives
GROUP BY
usr_id
) AS l2
...
How to avoid the “divide by zero” error in SQL?
...rder to avoid a "Division by zero" error we have programmed it like this:
Select Case when divisor=0 then null
Else dividend / divisor
End ,,,
But here is a much nicer way of doing it:
Select dividend / NULLIF(divisor, 0) ...
Now the only problem is to remember the NullIf bit, if I use the "/"...
How do I map lists of nested objects with Dapper
... probably work:
Grab the courses:
var courses = cnn.Query<Course>("select * from Courses where Category = 1 Order by CreationDate");
Grab the relevant mapping:
var mappings = cnn.Query<CourseLocation>(
"select * from CourseLocations where CourseId in @Ids",
new {Ids = course...
Firefox ignores option selected=“selected”
If you change a dropdown and refresh the page, Firefox seems to ignore the selected attribute.
20 Answers
...
Regex select all text between tags
What is the best way to select all the text between 2 tags - ex: the text between all the 'pre' tags on the page.
17 Answe...
Only parameterless constructors and initializers are supported in LINQ to Entities
... where nalTmp.idDziecko == idDziec
select new Payments
{
Imie = nalTmp.Dziecko.Imie,
Nazwisko = nalTmp.Dziecko.Nazwisko,
Nazwa= ...
How to split the name string in mysql?
...ast names. The middle name will show as NULL if there is no middle name.
SELECT
SUBSTRING_INDEX(SUBSTRING_INDEX(fullname, ' ', 1), ' ', -1) AS first_name,
If( length(fullname) - length(replace(fullname, ' ', ''))>1,
SUBSTRING_INDEX(SUBSTRING_INDEX(fullname, ' ', 2), ' ', -1) ,NU...
Selecting all text in HTML text input when clicked
...
You can use this javascript snippet:
<input onClick="this.select();" value="Sample Text" />
But apparently it doesn't work on mobile Safari. In those cases you can use:
<input onClick="this.setSelectionRange(0, this.value.length)" value="Sample Text" />
...