大约有 43,000 项符合查询结果（耗时：0.0303秒） [XML]
How to select all records from one table that do not exist in another table?
...
SELECT t1.name
FROM table1 t1
LEFT JOIN table2 t2 ON t2.name = t1.name
WHERE t2.name IS NULL
Q: What is happening here?
A: Conceptually, we select all rows from table1 and for each row we attempt to find a row in table2 wi...
What to do with “Unexpected indent” in python?
... allowed (at least on my version of Python), but Python assumes tabs are 8 characters long, which may not match your editor. Just say "no" to tabs. Most editors allow them to be automatically replaced by spaces.
The best way to avoid these issues is to always use a consistent number of spaces when ...
How to pass boolean values to a PowerShell script from a command prompt
... accept
booleans or numbers, use $true, $false, 1 or 0 instead.
At line:1 char:36
+ function f( [bool]$b ) { $b }; f -b <<<< '$false'
+ CategoryInfo : InvalidData: (:) [f], ParentContainsErrorRecordException
+ FullyQualifiedErrorId : ParameterArgumentTransformationErro...
SQL statement to select all rows from previous day
I am looking for a good SQL Statement to select all rows from the previous day from one table. The table holds one datetime column. I am using SQL Server 2005.
...
Opening a folder in explorer and selecting a file
I'm trying to open a folder in explorer with a file selected.
11 Answers
11
...
How to select rows that have current day's timestamp?
I am trying to select only today's records from a database table.
9 Answers
9
...
SQL - find records from one table which don't exist in another
...shortest statement, and may be quickest if your phone book is very short:
SELECT *
FROM Call
WHERE phone_number NOT IN (SELECT phone_number FROM Phone_book)
alternatively (thanks to Alterlife)
SELECT *
FROM Call
WHERE NOT EXISTS
(SELECT *
FROM Phone_book
WHERE Phone_book.phon...
When to use SELECT … FOR UPDATE?
Please help me understand the use-case behind SELECT ... FOR UPDATE .
2 Answers
2
...
SELECT INTO Variable in MySQL DECLARE causes syntax error?
I´d like to SELECT a single value into a variable. I´d tried to following:
11 Answers
...
Expert R users, what's in your .Rprofile? [closed]
...se it might breaks my coauthors' code, I wish it was the default. Why?
1) Character vectors use less memory (but only barely);
2) More importantly, we would avoid problems such as:
> x <- factor(c("a","b","c"))
> x
[1] a b c
Levels: a b c
> x <- c(x, "d")
> x
[1] "1" "2" "3" "...