大约有 45,000 项符合查询结果（耗时：0.0379秒） [XML]
Why do most C developers use define instead of const? [duplicate]
...s is actually my preference in such a case.
enum { FIELD_WIDTH = 16384 };
char buf[FIELD_WIDTH];
In C++ this is a huge advantage as you can scope your enum in a class or namespace, whereas you cannot scope a #define.
In C you don't have namespaces and cannot scope an enum inside a struct, and am...
How to send objects in NIB files to front/back?
...
Just to give a clean, up-to-date answer to this:
Select an interface object, then "Editor | Arrange | Send to back/front/etc", OR
Select the window object, then click on 'Window' above the interface editor and select the objects it contains
This pic shows where to click: ...
Selecting a row of pandas series/dataframe by integer index
...
The primary purpose of the DataFrame indexing operator, [] is to select columns.
When the indexing operator is passed a string or integer, it attempts to find a column with that particular name and return it as a Series.
So, in the question above: df[2] searches for a column name matchin...
Difference between 2 dates in SQLite
...
SELECT julianday('now') - julianday(DateCreated) FROM Payment;
share
|
improve this answer
|
follo...
What is base 64 encoding used for?
...You never know -- some protocols may interpret your binary data as control characters (like a modem), or your binary data could be screwed up because the underlying protocol might think that you've entered a special character combination (like how FTP translates line endings).
So to get around th...
#1071 - Specified key was too long; max key length is 767 bytes
...o 3072 bytes.
You also have to be aware that if you set an index on a big char or varchar field which is utf8mb4 encoded, you have to divide the max index prefix length of 767 bytes (or 3072 bytes) by 4 resulting in 191. This is because the maximum length of a utf8mb4 character is four bytes. For a...
Dropping Unique constraint from MySQL table
...AINT unq_tab_id UNIQUE(id));
-- checking constraint name if autogenerated
SELECT * FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE TABLE_NAME = 'tab';
-- dropping constraint
ALTER TABLE tab DROP CONSTRAINT unq_tab_id;
db<>fiddle demo
...
Disabling highlighting of current line in the Visual Studio editor
... in Fonts and Colors dialog controls the background color of the currently selected line in the editor?
6 Answers
...
What are the most common SQL anti-patterns? [closed]
...ost programmers' tendency to mix their UI-logic in the data access layer:
SELECT
FirstName + ' ' + LastName as "Full Name",
case UserRole
when 2 then "Admin"
when 1 then "Moderator"
else "User"
end as "User's Role",
case SignedIn
when 0 then "Logged i...
【可动态编辑表格】App Inventor 2 Dynamic Editable HTML Table - App应用...
...mary key), and then the other data columns, for example data returned by a SELECT query from an sqlite/mysql database or similar dataset from a google sheet. Therefore it will not let you edit the id (primary key row) because this is essential unique data and should not be changed. If you add a new ...