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ORA-00054: resource busy and acquire with NOWAIT specified or timeout expired
...table is already locked by some query. For example, you may have executed "select for update" and have not yet committed/rollbacked and fired another select query. Do a commit/rollback before executing your query.
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Get selected subcommand with argparse
When I use subcommands with python argparse, I can get the selected arguments.
2 Answers
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Create code first, many to many, with additional fields in association table
...OfMembers = context.Members
.Where(m => m.LastName == "Smith")
.SelectMany(m => m.MemberComments.Select(mc => mc.Comment))
.ToList();
... or ...
var commentsOfMembers = context.MemberComments
.Where(mc => mc.Member.LastName == "Smith")
.Select(mc => mc.Comment)
...
What is LINQ and what does it do? [closed]
...;string> result =
from c in myCustomers
where c.Name.StartsWith("B")
select c.Name;
Lambda Expressions - This is a shorthand for specifying a method. The C# compiler will translate each into either an anonymous method or a true System.Linq.Expressions.Expression. You really need to understand...
Oracle “(+)” Operator
...dize OUTER joins.
The query would be re-written in ANSI-92 syntax as:
SELECT ...
FROM a
LEFT JOIN b ON b.id = a.id
This link is pretty good at explaining the difference between JOINs.
It should also be noted that even though the (+) works, Oracle recommends not using it:
Oracle re...
How can I split and trim a string into parts all on one line?
...
Try
List<string> parts = line.Split(';').Select(p => p.Trim()).ToList();
FYI, the Foreach method takes an Action (takes T and returns void) for parameter, and your lambda return a string as string.Trim return a string
Foreach extension method is meant to modif...
What is SELF JOIN and when would you use it? [duplicate]
...et information for both people in one row, you could self join like this:
select e1.EmployeeID,
e1.FirstName,
e1.LastName,
e1.SupervisorID,
e2.FirstName as SupervisorFirstName,
e2.LastName as SupervisorLastName
from Employee e1
left outer join Employee e2 on e1.SupervisorID ...
JPA eager fetch does not join
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JPA doesn't provide any specification on mapping annotations to select fetch strategy. In general, related entities can be fetched in any one of the ways given below
SELECT => one query for root entities + one query for related mapped entity/collection of each root entity = (n+1) que...
A generic list of anonymous class
... okay cool, now we need an example of replacing the new {} lines with a select statement. var list = sourceList.Select( o => new { o.ModelId, ...
How to undo another user’s checkout in TFS?
...t-clicking the desired project, folder, or file in Source Control Explorer
Select Properties
Select the Security tab
Select the appropriate user or group in the Users and Groups section at the top
View the "Permissions for [user/group]:" section at the bottom
Deleting the workspace
tf workspace /...