大约有 40,000 项符合查询结果（耗时：0.0452秒） [XML]
IN vs OR in the SQL WHERE Clause
...h are nearly instant. When the column is not indexed I got these results:
SELECT COUNT(*) FROM t_inner WHERE val IN (1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000);
1 row fetched in 0.0032 (1.2679 seconds)
SELECT COUNT(*) FROM t_inner WHERE val = 1000 OR val = 2000 OR val = 3000 OR val = 40...
Can I bind an array to an IN() condition?
...(0, count($ids), '?'));
$db = new PDO(...);
$stmt = $db->prepare(
'SELECT *
FROM table
WHERE id IN(' . $inQuery . ')'
);
// bindvalue is 1-indexed, so $k+1
foreach ($ids as $k => $id)
$stmt->bindValue(($k+1), $id);
$stmt->execute();
?>
fix: dan, you were right. ...
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[...
How to do a regular expression replace in MySQL?
...ositions and perform substring substitution and extraction, respectively.
SELECT REGEXP_REPLACE('Stackoverflow','[A-Zf]','-',1,0,'c');
-- Output:
-tackover-low
DBFiddle Demo
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improve this ...
best way to add license section to iOS settings bundle
...save it to the root of your project.
Expand the Settings.bundle group and select Root.plist. You will need to add a new section where its key will be Preference Items of type Array. Add the following information:
The Filename key points to the plist that was created by this script. You can cha...
ng-model for `` (with directive DEMO)
...cope.fileread = changeEvent.target.files[0];
// or all selected files:
// scope.fileread = changeEvent.target.files;
});
});
}
}
}]);
share
...
Open terminal here in Mac OS finder [closed]
...not just Finder, and they operate on folders as well as absolute pathnames selected in text.
You can even assign command keys to them.
Services appear in the Services submenu of each application menu, and within the contextual menu (Control-Click or Right-Click on a folder or pathname).
The New T...
Use tab to indent in textarea
...which;
if (keyCode == 9) {
e.preventDefault();
var start = this.selectionStart;
var end = this.selectionEnd;
// set textarea value to: text before caret + tab + text after caret
$(this).val($(this).val().substring(0, start)
+ "\t"
+ $(this).val...
Oracle PL/SQL - How to create a simple array variable?
... INDEX BY PLS_INTEGER;
employee_array employee_arraytype;
BEGIN
SELECT *
BULK COLLECT INTO employee_array
FROM employee
WHERE department = 10;
--
FOR i IN employee_array.FIRST .. employee_array.LAST
LOOP
-- Do something
END LOOP;
END;
The associative arra...
SQL JOIN - WHERE clause vs. ON clause
...
They are not the same thing.
Consider these queries:
SELECT *
FROM Orders
LEFT JOIN OrderLines ON OrderLines.OrderID=Orders.ID
WHERE Orders.ID = 12345
and
SELECT *
FROM Orders
LEFT JOIN OrderLines ON OrderLines.OrderID=Orders.ID
AND Orders.ID = 12345
The first will re...