大约有 3,551 项符合查询结果（耗时：0.0297秒） [XML]
Django in / not in query
...ite to exact. Author.objects.filter(name__ne='Jack') will translate to the SQL: "author"."name" <> 'Jack'"
from django.db.models import Lookup
class NotEqual(Lookup):
lookup_name = 'ne'
def as_sql(self, compiler, connection):
lhs, lhs_params = self.process_lhs(compiler, conn...
How to find gaps in sequential numbering in mysql?
...ve, syntax can be generated for other programming languages. Or maybe even SQL.
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string.ToLower() and string.ToLowerInvariant()
... in Turkey.
=Using ToLower incorrectly=
Now pretend you are writing an SQL parser. Somewhere you will have code that looks like:
if(operator.ToLower() == "like")
{
// Handle an SQL LIKE operator
}
The SQL grammar does not change when you change cultures. A Frenchman does not write SÉLECT...
Compare two data.frames to find the rows in data.frame 1 that are not present in data.frame 2
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SQLDF provides a nice solution
a1 <- data.frame(a = 1:5, b=letters[1:5])
a2 <- data.frame(a = 1:3, b=letters[1:3])
require(sqldf)
a1NotIna2 <- sqldf('SELECT * FROM a1 EXCEPT SELECT * FROM a2')
And the rows which...
PHP - Modify current object in foreach loop
...logic.
For retrieving objects by ID / PK, depending upon if you are using SQL or not (it seems suggested), I'd use a filter to ensure I get an array of valid PK's, then implode with comma and place into an SQL IN() clause to return the result-set. It makes one call instead of several via SQL, optim...
Are GUID collisions possible?
I'm working on a database in SQL Server 2000 that uses a GUID for each user that uses the app it's tied to. Somehow, two users ended up with the same GUID. I know that microsoft uses an algorithm to generate a random GUID that has an extremely low chance of causing collisons, but is a collision stil...
JOIN two SELECT statement results
Is it possible to join the results of 2 sql SELECT statements in one statement?
I have a database of tasks where each record is a separate task, with deadlines (and a PALT , which is just an INT of days from start to deadline. Age is also an INT number of days.)
...
What is a NullReferenceException, and how do I fix it?
... at once. Note: It does not matter which data provider you are using -- MySQL, SQL Server, OleDB, etc. -- the concepts are the same.
Example 1
Dim da As OleDbDataAdapter
Dim ds As DataSet
Dim MaxRows As Integer
con.Open()
Dim sql = "SELECT * FROM tblfoobar_List"
da = New OleDbDataAdapter(sql, con)...
Rails Model find where not equal
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Vikrant's answer does provide a solution doesn't involve sql or including another gem. But, I stand corrected, your answer is definitely the most coder-friendly/fancy.
– tybro0103
Jun 22 '12 at 0:22
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How to find current transaction level?
How do you find current database's transaction level on SQL Server?
5 Answers
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