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data.table vs dplyr: can one do something well the other can't or does poorly?
... ## data.table syntax
left_join(DT2, DT1) ## dplyr syntax
# 2. select columns while join
DT1[DT2, .(z, i.mul)]
left_join(select(DT2, x, y, mul), select(DT1, x, y, z))
# 3. aggregate while join
DT1[DT2, .(sum(z) * i.mul), by = .EACHI]
DF1 %>% group_by(x, y) %>% summarise(z = su...
“Incorrect string value” when trying to insert UTF-8 into MySQL via JDBC?
...
The second approach should be used selectively, i. e. never be applied to SELECT queries, as set names utf8mb4; select ... from ... will never produce a ResultSet and instead result in a ResultSet is from UPDATE. No Data. error.
– Bass
...
Why is Visual Studio 2013 very slow?
...available" check box to prevent the use of hardware graphics acceleration.
Select or clear the "Enable rich client visual experience" check box to make sure that rich visuals are always on or off, respectively. When this check box is selected, rich visuals are used independent of the computer enviro...
git stash apply version
...
git stash list
then select the stash to apply and use only number:
git stash apply 1
share
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improve this answer
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fo...
Doctrine - How to print out the real sql, not just the prepared statement?
...hoWriteSQLWithoutParamsLogger implements SQLLogger
{
const QUERY_TYPE_SELECT="SELECT";
const QUERY_TYPE_UPDATE="UPDATE";
const QUERY_TYPE_INSERT="INSERT";
const QUERY_TYPE_DELETE="DELETE";
const QUERY_TYPE_CREATE="CREATE";
const QUERY_TYPE_ALTER="ALTER";
private $dbPlat...
App Inventor 2 SQLite 拓展：超流行兼容主流SQL语法的迷你本地数据库引擎 ...
...允许您修改数据库以使其兼容。
此设置会影响各种 Select 方法返回结果行的方式。
当此属性为 false 时，Select 方法返回的列表中的每个元素将是一个简单的值列表，这些值表示为每个匹配行选择的列的值。
当此属性为 true ...
What is the precise meaning of “ours” and “theirs” in git?
...ics:
Merges:
$ git checkout master
$ git merge feature
If you want to select the version in master:
$ git checkout --ours codefile.js
If you want to select the version in feature:
$ git checkout --theirs codefile.js
Rebases:
$ git checkout feature
$ git rebase master
If you want to s...
Importing CommonCrypto in a Swift framework
...code.app path which can vary system-to-system, especially if you use xcode-select to switch to a beta version, or are building on a CI server where multiple versions are installed in non-standard locations. You also don't need to hard code the SDK so this should work for iOS, macOS, etc. You also do...
Get data from file input in JQuery
...tml>
<head>
<script>
function handleFileSelect()
{
if (!window.File || !window.FileReader || !window.FileList || !window.Blob) {
alert('The File APIs are not fully supported in this browser.');
return;
}
...
Duplicate and rename Xcode project & associated folders [closed]
...ame or any associated folders at this stage.
In Xcode, rename the project. Select your project from the navigator pane (left pane). In the Utilities pane (right pane) rename your project, Accept the changes Xcode proposes.
In Xcode, rename the schemes in "Manage Schemes", also rename any targets you...