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In MySQL queries, why use join instead of where?
...FROM clause
Write the association between the tables in the WHERE clause
SELECT *
FROM TABLE_A a,
TABLE_B b
WHERE a.id = b.id
Here's the query re-written using ANSI-92 JOIN syntax:
SELECT *
FROM TABLE_A a
JOIN TABLE_B b ON b.id = a.id
From a Performance Perspective:
Where su...
How can I efficiently select a Standard Library container in C++11?
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Differences between INDEX, PRIMARY, UNIQUE, FULLTEXT in MySQL?
...e - which are typically implemented internally using b-trees (allowing for selecting, sorting or ranges starting from left most column) or hash tables (allowing for selection starting from left most column).
Where the other index types are general-purpose, a FULLTEXT index is specialised, in that it...
Faster s3 bucket duplication
...
If you don't mind using the AWS console, you can:
Select all of the files/folders in the first bucket
Click Actions > Copy
Create a new bucket and select it
Click Actions > Paste
It's still fairly slow, but you can leave it alone and let it do its thing.
...
A weighted version of random.choice
...dom.choice (each element in the list has a different probability for being selected). This is what I came up with:
25 Answ...
Writing data into CSV file in C#
...re the values
var allLines = (from trade in proposedTrades
select new object[]
{
trade.TradeType.ToString(),
trade.AccountReference,
trade.SecurityCodeType.ToString(),
trade.SecurityC...
Convert MySql DateTime stamp into JavaScript's Date format
...d.
A MySQL DATETIME column can be converted to a unix timestamp through:
SELECT unix_timestamp(my_datetime_column) as stamp ...
We can make a new JavaScript Date object by using the constructor that requires milliseconds since the epoch. The unix_timestamp function returns seconds since the epoc...
There is already an open DataReader associated with this Command which must be closed first
...s =
from account in context.Accounts
from guranteer in account.Gurantors
select new AccountsReport
{
CreditRegistryId = account.CreditRegistryId,
AccountNumber = account.AccountNo,
DateOpened = account.DateOpened,
};
return accounts.AsEnumerable()
.Select((account, ind...
How to have an automatic timestamp in SQLite?
....200');
INSERT INTO my_table(name) VALUES('test3');
This is the result:
SELECT * FROM my_table;
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mysql - how many columns is too many?
...every column to be returned by every query is perfectly normal; that's why SELECT statement lets you explicitly name the columns you need.
As a general rule, your table structure should reflect your domain model; if you really do have 70 (100, what have you) attributes that belong to the same entit...