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Why is SELECT * considered harmful?
...work. This is especially true when someone adds new columns to underlying tables that didn't exist and weren't needed when the original consumers coded their data access.
Indexing issues. Consider a scenario where you want to tune a query to a high level of performance. If you were to use *, and ...
Disable Laravel's Eloquent timestamps
... we don't want to add the updated_at / created_at fields to all of our tables as we have a logging class that does all this in more depth for us already.
...
How to write a foreach in SQL Server?
...rforms better than a cursor and is simpler:
DECLARE @PractitionerList TABLE(PracticionerID INT)
DECLARE @PractitionerID INT
INSERT @PractitionerList(PracticionerID)
SELECT PracticionerID
FROM Practitioner
WHILE(1 = 1)
BEGIN
SET @PracticionerID = NULL
S...
Why are Oracle table/column/index names limited to 30 characters?
...haracters long. Allowing every line of code that goes something like
l_table_name VARCHAR2(30);
BEGIN
SELECT table_name
INTO l_table_name
FROM dba_tables
WHERE ...
to suddenly break because the DBA 15 years ago used VARCHAR2(30) rather than DBA_TABLES.TABLE_NAME%TYPE in the script...
How to scroll to the bottom of a UITableView on the iPhone before the view appears
I have a UITableView that is populated with cells of a variable height. I would like the table to scroll to the bottom when the view is pushed into view.
...
Oracle: how to UPSERT (update or insert into a table?)
The UPSERT operation either updates or inserts a row in a table, depending if the table already has a row that matches the data:
...
List all the files that ever existed in a Git repository
...$ git ff create
A database/migrations/2014_10_12_000000_create_users_table.php
A database/migrations/2014_10_12_100000_create_password_resets_table.php
A database/migrations/2015_05_11_200932_create_boletin_table.php
A database/migrations/2015_05_15_133500_create_usuarios_tab...
Foreign Key to non-primary key
I have a table which holds data, and one of those rows needs to exist in another table. So, I want a foreign key to maintain referential integrity.
...
Efficiently convert rows to columns in sql server
...Code, LastName, AccountNumber
from
(
select value, columnname
from yourtable
) d
pivot
(
max(value)
for columnname in (Firstname, Amount, PostalCode, LastName, AccountNumber)
) piv;
See Demo.
Pivot with unknown number of columnnames
If you have an unknown number of columnnames that you w...
sqlite alter table add MULTIPLE columns in a single statement
Is it possible to alter table add MULTIPLE columns in a single statement in sqlite?
The following would not work.
4 Answers...