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How do I explicitly specify a Model's table-name mapping in Rails?
I have a Model class called Countries and I want it to map to a DB table called 'cc'.
2 Answers
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SQLAlchemy: cascade delete
...relationship doesn't dictate the parent-child setup. Using ForeignKey on a table is what sets it up as the child. It doesn't matter if the relationship is on the parent or child.
– d512
Aug 4 '16 at 2:04
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Fastest way to flatten / un-flatten nested JSON objects
...object:
var flatten = (function (isArray, wrapped) {
return function (table) {
return reduce("", {}, table);
};
function reduce(path, accumulator, table) {
if (isArray(table)) {
var length = table.length;
if (length) {
var index ...
Counting the number of elements with the values of x in a vector
...
You can just use table():
> a <- table(numbers)
> a
numbers
4 5 23 34 43 54 56 65 67 324 435 453 456 567 657
2 1 2 2 1 1 2 1 2 1 3 1 1 1 1
Then you can subset it:
> a[names(a)==435]
4...
Generate table relationship diagram from existing schema (SQL Server) [closed]
Is there a way to produce a diagram showing existing tables and their relationships given a connection to a database?
9 Ans...
MySQL maximum memory usage
...the (f'ing) manual.
As for the database -- a few important constraints:
table engine (InnoDB, MyISAM, ...)
size
indices
usage
Most MySQL tips on stackoverflow will tell you about 5-8 so called important settings. First off, not all of them matter - e.g. allocating a lot of resources to InnoDB a...
Mean per group in a data.frame [duplicate]
...ype of operation is exactly what aggregate was designed for:
d <- read.table(text=
'Name Month Rate1 Rate2
Aira 1 12 23
Aira 2 18 73
Aira 3 19 45
Ben 1 53 19
Ben 2 22 87
Ben 3 19 ...
Oracle PL/SQL - How to create a simple array variable?
...n Oracle PL/SQL that uses pure memory, they all seem to be associated with tables. I'm looking to do something like this in my PL/SQL (C# syntax):
...
How to find a text inside SQL Server procedures / triggers?
...
Just be aware that the syscomments table stores the values in 8000-character chunks, so if you are unlucky enough to have the text you're searching for split across one of these boundaries, you won't find it with this method.
– ErikE
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Select where count of one field is greater than one
...e result comparison.
Taking the query at face value:
SELECT *
FROM db.table
HAVING COUNT(someField) > 1
Ideally, there should be a GROUP BY defined for proper valuation in the HAVING clause, but MySQL does allow hidden columns from the GROUP BY...
Is this in preparation for a unique cons...