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how do I query sql for a latest record date for each user
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select t.username, t.date, t.value
from MyTable t
inner join (
select username, max(date) as MaxDate
from MyTable
group by username
) tm on t.username = tm.username and t.date = tm.MaxDate
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Check if all checkboxes are selected
How do I check if all checkboxes with class="abc" are selected?
9 Answers
9
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How can I delete multiple lines in vi?
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I find this easier
Go VISUAL mode Shift+v
Select lines
d to delete
https://superuser.com/questions/170795/how-can-i-select-and-delete-lines-of-text-in-vi
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i...
How do I restore a dump file from mysqldump?
... following these steps…
Open MySQL Administrator and connect to server
Select "Catalogs" on the left
Right click in the lower-left box and choose "Create New Schema"
MySQL Administrator http://img204.imageshack.us/img204/7528/adminsx9.th.gif enlarge image
Name the new schema (example: "dbn")
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使用 C++ 处理 JSON 数据交换格式 - C/C++ - 清泛网 - 专注C/C++及内核技术
...单的例子。
Json::Reader reader;
Json::Value json_object;
const char* json_document = "{/"age/" : 26,/"name/" : /"huchao/"}";
if (!reader.parse(json_document, json_object))
return 0;
std::cout << json_object["name"] << std::endl;
std::cout << json_object["age"] << std::endl;
输...
INSERT IF NOT EXISTS ELSE UPDATE?
...ike:
insert or replace into Book (ID, Name, TypeID, Level, Seen) values
((select ID from Book where Name = "SearchName"), "SearchName", ...);
Note that any field not in the insert list will be set to NULL if the row already exists in the table. This is why there's a subselect for the ID column: I...
App Inventor 2 项目合并工具 AIMerge · App Inventor 2 中文网
... CountDownScreen1 project, then clicking on the “Project” dropdown and selecting “Export selected project (.aia) to my computer”. Figure 4 shows how to select a project and where to click to download the project.
Figure 4: Steps to download the CountDownScreen1 project
Developer 2 Work I...
StringUtils.isBlank() vs String.isEmpty()
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StringUtils.isBlank() checks that each character of the string is a whitespace character (or that the string is empty or that it's null). This is totally different than just checking if the string is empty.
From the linked documentation:
Checks if a String is whi...
How to recover a dropped stash in Git?
...t/ {print $3}'
...or using Powershell for Windows:
git fsck --no-reflog | select-string 'dangling commit' | foreach { $_.ToString().Split(" ")[2] }
This will show you all the commits at the tips of your commit graph which are no longer referenced from any branch or tag – every lost commit, inclu...
XPath: How to select nodes which have no attributes?
Using XPath, how to select nodes which have no attributes (where attribute count = 0)?
3 Answers
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