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Ways to save enums in database
...g.
But if you wanted to really do that, i would create a Suits dimension table:
| Suit | SuitID | Rank | Color |
|------------|--------------|---------------|--------|
| Unknown | 4 | 0 | NULL |
| Heart | 1 | 1 | Red ...
Change a column type from Date to DateTime during ROR migration
...
First in your terminal:
rails g migration change_date_format_in_my_table
Then in your migration file:
For Rails >= 3.2:
class ChangeDateFormatInMyTable < ActiveRecord::Migration
def up
change_column :my_table, :my_column, :datetime
end
def down
change_column :my_tabl...
Update multiple columns in SQL
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Try this:
UPDATE table1
SET a = t2.a, b = t2.b, .......
FROM table2 t2
WHERE table1.id = t2.id
That should work in most SQL dialects, excluding Oracle.
And yes - it's a lot of typing - it's the way SQL does this.
...
FIND_IN_SET() vs IN()
I have 2 tables in my database. One is for orders, and one is for companies.
6 Answers
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Parse JSON in TSQL
...le Talk website that outlines how to take a JSon string and output it into tables and columns that can be queried. This is for SQL Server 2016: https://www.simple-talk.com/sql/learn-sql-server/json-support-in-sql-server-2016/
– codeaf
Jul 28 '16 at 18:10
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The multi-part identifier could not be bound
...
FROM (a, b) LEFT JOIN dkcd ON …
WHERE …
that is, the combination of tables a and b is joined with the table dkcd. In fact, what's happening is
SELECT
…
FROM a, (b LEFT JOIN dkcd ON …)
WHERE …
that is, as you may already have understood, dkcd is joined specifically against b and onl...
How to customize the background color of a UITableViewCell?
...ike to customize the background (and maybe the border too) of all of the UITableViewCells within my UITableView. So far I have not been able to customize this stuff, so I have a bunch of white background cells which is the default.
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Check if value exists in Postgres array
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how can I search for a column from another table to have a value in the array? e.g. select * from beers where style_id in (select preferences from users where id=1) limit 1; style_id is an integer data type; preferences is integer[] I get this error ERROR: operato...
Is there any performance gain in indexing a boolean field?
...is is not entirely correct, without an index mySql needs to scan the whole table to find the relevant rows.
– ilanco
May 9 '12 at 22:04
4
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How to write the Fibonacci Sequence?
...bject every time the function is called, but normally you wouldn't use a mutable default argument for exactly this reason):
def mem_fib(n, _cache={}):
'''efficiently memoized recursive function, returns a Fibonacci number'''
if n in _cache:
return _cache[n]
elif n > 1:
...