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How to delete or add column in SQLITE?
... as long as you do a create new table first instead of a create from select, it will have all those things.
– John Lord
Jul 3 '19 at 15:28
1
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How do MySQL indexes work?
...be faster to go through the pages one by one (in a database, this is "poor selectivity").
For a 10-page book, it makes no sense to make an index, as you may end up with a 10-page book prefixed by a 5-page index, which is just silly - just scan the 10 pages and be done with it.
The index also needs t...
Add disabled attribute to input element using Javascript
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Working code from my sources:
HTML WORLD
<select name="select_from" disabled>...</select>
JS WORLD
var from = jQuery('select[name=select_from]');
//add disabled
from.attr('disabled', 'disabled');
//remove it
from.removeAttr("disabled");
...
Difference between a theta join, equijoin and natural join
...ed SQL query would be like this (you can play with all the examples here)
SELECT *
FROM Product
JOIN Component
ON Product.Pname = Component.Pname
and the result:
| PNAME | PRICE | CNAME | COST |
----------------------------------
| Laptop | 1500 | CPU | 500 |
| Laptop | 1500 | hdd ...
Intellij IDEA: Hotkey for “scroll from source”
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In the latest IntelliJ IDEA, there is a keymap entry called "Select in Project View" with no default shortcut. Just add a shortcut key to it. No need for a plugin.
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SQL NVARCHAR and VARCHAR Limits
... large (unavoidable) dynamic SQL query. Due to the number of fields in the selection criteria the string containing the dynamic SQL is growing over 4000 chars. Now, I understand that there is a 4000 max set for NVARCHAR(MAX) , but looking at the executed SQL in Server Profiler for the statement
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How to insert a line break in a SQL Server VARCHAR/NVARCHAR string
...NVARCHAR(100)
SET @text = 'This is line 1.' + CHAR(13) + 'This is line 2.'
SELECT @text
This prints out the following:
This is line 1.
This is line 2.
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Error 908: Permission RECEIVE_SMS has been denied. - App Inventor 2 中...
这篇帖子是关于在MIT App Inventor中遇到错误908（权限接收短信）的讨论。一位用户遇到了这个问题，并询问是否有人知道如何解决。其他用户提供了一些可能的解决方案，包括检查应用程序权限设置、确保手机上的权限设置正确...
Remove all spaces from a string in SQL Server
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Simply replace it;
SELECT REPLACE(fld_or_variable, ' ', '')
Edit:
Just to clarify; its a global replace, there is no need to trim() or worry about multiple spaces for either char or varchar:
create table #t (
c char(8),
v varchar(8))...
Replace String in all files in Eclipse
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Thank you I solved this way. 1.- Select the text to search 2.- Go to Menu Search >Text > Project, a listing of ocurrences pops up, within the search view. 3.- Right Click on the root of that list, 4.- Select Replace All... 5.- Input the text to replace...