大约有 47,000 项符合查询结果(耗时:0.0404秒) [XML]

https://stackoverflow.com/ques... 

How to delete a row by reference in data.table?

...el.idxs' vs. 'keep.idxs' keep.idxs <- setdiff(DT[, .I], del.idxs); # select row indexes to keep cols = names(DT); DT.subset <- data.table(DT[[1]][keep.idxs]); # this is the subsetted table setnames(DT.subset, cols[1]); for (col in cols[2:length(cols)]) { DT.subset[, (col) := DT[...
https://stackoverflow.com/ques... 

jQuery Selector: Id Ends With?

Is there a selector that I can query for elements with an ID that ends with a given string? 9 Answers ...
https://stackoverflow.com/ques... 

XPath: How to select elements based on their value?

...st thing is when using [], there are only two types of data: [number] to select a node from node-set [bool] to filter a node-set from node-set In this case, the value is evaluated to boolean by function boolean(), and there is a rule: Filters are always evaluated with respect to a context. ...
https://stackoverflow.com/ques... 

How to create relationships in MySQL

...s defined as the default storage engine,can check using command (mysql> SELECT @@default_storage_engine;) – Arun Feb 18 at 4:00 add a comment  |  ...
https://stackoverflow.com/ques... 

This Row already belongs to another table error when trying to add rows?

I have a DataTable which has some rows and I am using the select to filter the rows to get a collection of DataRows which I then loop through using foreach and add it to another DataTable, but it is giving me the error "This Row already belongs to another table". Here is the code: ...
https://stackoverflow.com/ques... 

MySQL convert date string to Unix timestamp

... Here's an example of how to convert DATETIME to UNIX timestamp: SELECT UNIX_TIMESTAMP(STR_TO_DATE('Apr 15 2012 12:00AM', '%M %d %Y %h:%i%p')) Here's an example of how to change date format: SELECT FROM_UNIXTIME(UNIX_TIMESTAMP(STR_TO_DATE('Apr 15 2012 12:00AM', '%M %d %Y %h:%i%p')),'%m-%d-...
https://stackoverflow.com/ques... 

What's the difference between NOT EXISTS vs. NOT IN vs. LEFT JOIN WHERE IS NULL?

... using Standard SQL. An obvious omission is the equivalent using EXCEPT: SELECT a FROM table1 EXCEPT SELECT a FROM table2 Note in Oracle you need to use the MINUS operator (arguably a better name): SELECT a FROM table1 MINUS SELECT a FROM table2 Speaking of proprietary syntax, there may also ...
https://stackoverflow.com/ques... 

How to select an element by classname using jqLite?

...y, and as-noted by @kevin-b: // find('#id') angular.element(document.querySelector('#id')) //find('.classname'), assumes you already have the starting elem to search from angular.element(elem.querySelector('.classname')) Note: If you're looking to do this from your controllers you may want to ha...
https://stackoverflow.com/ques... 

Cleanest way to build an SQL string in Java

...uild an SQL string to do database manipulation (updates, deletes, inserts, selects, that sort of thing) - instead of the awful string concat method using millions of "+"'s and quotes which is unreadable at best - there must be a better way. ...
https://stackoverflow.com/ques... 

jquery how to empty input field

... On a related note, .val([]) can also unselect any selected option in select list... not so much with .val(''). Best thing about it is it's cross-browser support. P.S: This is an alternative to only other efficient cross-browser solution - $("select option").prop("...