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How to define two fields “unique” as couple
... How would you handle this say if volume_number could be null? Mysql won't seem to enforce unique in that case.
– Greg
Jun 27 '11 at 17:28
27
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Android View.getDrawingCache returns null, only null
...
View root = currActivity.getWindow().getDecorView().findViewById(android.R.id.content); root.setDrawingCacheEnabled(true); root.layout(0, 0, 480, 854); mBitmap = root.getDrawingCache();
...
INSERT with SELECT
... lets you put whatever you inserted into another table also. I don't think MySQL has an equivalent. You might create a temporary table, select into that table, then populate courses from that table, then use the temp table for whatever else you needed.
– Andrew
...
How to disable back swipe gesture in UINavigationController on iOS 7
...etting the delegate to nil leads to hanging issues when you go back to the root view controller and make a swipe gesture before navigating elsewhere.
The following example assumes iOS 7:
{
id savedGestureRecognizerDelegate;
}
- (void)viewWillAppear:(BOOL)animated
{
savedGestureRecognizer...
What does the KEY keyword mean?
In this MySQL table definition:
2 Answers
2
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SQL UPDATE all values in a field with appended string CONCAT not working
...
That's pretty much all you need:
mysql> select * from t;
+------+-------+
| id | data |
+------+-------+
| 1 | max |
| 2 | linda |
| 3 | sam |
| 4 | henry |
+------+-------+
4 rows in set (0.02 sec)
mysql> update t set data=concat(d...
Laravel Schema onDelete set null
...cument what options there are, but I think you can assume it's the default mysql values (see ../ vendor / laravel / framework / src / Illuminate / Database / Schema / Grammars / Grammar.php)
– Dirk Jan
Mar 23 at 14:47
...
How to perform file system scanning
...tf("Visited: %s\n", path)
return nil
}
func main() {
flag.Parse()
root := flag.Arg(0)
err := filepath.Walk(root, visit)
fmt.Printf("filepath.Walk() returned %v\n", err)
}
Please note that filepath.Walk walks the directory tree recursively.
This is an example run:
$ mkdir -p dir1/dir...
Cannot change column used in a foreign key constraint
... DELETE ) will wait till timeout or UNLOCK TABLES; is executed
http://dev.mysql.com/doc/refman/5.5/en/lock-tables.html
EDIT 2: OP asked for a more detailed explanation of the line "The type and definition of foreign key field and reference must be equal. This means your foreign key disallows chang...
Remove duplicate entries using a Bash script [duplicate]
...s. Interestingly enough the same record set took 15.1 seconds to perform a MySQL DISTINCT query on.
– Tegan Snyder
Feb 11 '16 at 19:13
1
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