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How to remove a column from an existing table?
...lete a column from an unexisting table ;-)
BEGIN TRANSACTION
IF exists (SELECT * FROM sys.columns c
INNER JOIN sys.objects t ON (c.[object_id] = t.[object_id])
WHERE t.[object_id] = OBJECT_ID(N'[dbo].[MyTable]')
AND c.[name] = 'ColumnName')
BEGIN TRY
ALTER TABLE [dbo].[MyTable] DRO...
How to run iPhone emulator WITHOUT starting Xcode?
...s an icon for the simulator in the dock area. Right-click on that icon and select Options - Keep in Dock.
– RenniePet
Mar 8 '17 at 10:43
|
s...
Xcode - How to fix 'NSUnknownKeyException', reason: … this class is not key value coding-compliant f
...ng from "File's Owner" under "Place Holders" to "view" under "Objects" and selecting the view outlet.
– Nirma
Aug 11 '11 at 14:49
...
MySQL Insert into multiple tables? (Database normalization?)
... 2 and 3:
Will stock the LAST_INSERT_ID() in
a MySQL variable:
INSERT ...
SELECT LAST_INSERT_ID() INTO @mysql_variable_here;
INSERT INTO table2 (@mysql_variable_here, ...);
INSERT INTO table3 (@mysql_variable_here, ...);
Will stock the LAST_INSERT_ID() in a
php variable (or any language that
can c...
Convert an image (selected by path) to base64 string
How do you convert an image from a path on the user's computer to a base64 string in C#?
12 Answers
...
Getting jQuery to recognise .change() in IE
..., in my testing this is not correct and jquery's click does trigger when i select the next radio button using arrow keys. (vista, ie7)
– svandragt
Nov 7 '08 at 13:51
1
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postgresql COUNT(DISTINCT …) very slow
...
You can use this:
SELECT COUNT(*) FROM (SELECT DISTINCT column_name FROM table_name) AS temp;
This is much faster than:
COUNT(DISTINCT column_name)
share
...
How to get the index of an item in a list in a single step?
...g different (e.g. on top of any IEnumerable<>).
Use the overload of Select which takes an index in the predicate, so you transform your list into an (index, value) pair:
var pair = myList.Select((Value, Index) => new { Value, Index })
.Single(p => p.Value.Prop == oProp...
MySQL error 1449: The user specified as a definer does not exist
...finer for views
Run this SQL to generate the necessary ALTER statements
SELECT CONCAT("ALTER DEFINER=`youruser`@`host` VIEW ",
table_name, " AS ", view_definition, ";")
FROM information_schema.views
WHERE table_schema='your-database-name';
Copy and run the ALTER statements
How to change the...
SQL中使用update inner join和delete inner join；Oracle delete join替代...
...
下面是Oracle的：
Sql代码
DELETE TABLE1 where KHID exists ( select KHID from table2 where FWDWID=8)
Sql代码
DELETE TABLE1 where exists ( select 1 from table2 where and table1.khid=table2.khid and FWDWID=8);
Oracle的delete与join如何使用
delete from A where sid i...