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Rails 3 migrations: Adding reference column?
...class AddUserToTester < ActiveRecord::Migration
def change
change_table :testers do |t|
t.references :user, index: true
end
end
def down
change_table :testers do |t|
t.remove :user_id
end
end
end
c.f.: http://apidock.com/rails/ActiveRecord/ConnectionAdapters...
How to set the UITableView Section title programmatically (iPhone/iPad)?
I've created a UITableView in Interface Builder using storyboards . The UITableView is setup with static cells and a number of different sections.
...
Naming convention for unique constraint
...rimary key and foreign key have commonly used and obvious conventions ( PK_Table and FK_Table_ReferencedTable , respectively). The IX_Table_Column naming for indexes is also fairly standard.
...
What does SQL clause “GROUP BY 1” mean?
...d name, you may also group by ordinal, or position of the field within the table. 1 corresponds to the first field (regardless of name), 2 is the second, and so on.
This is generally ill-advised if you're grouping on something specific, since the table/view structure may change. Additionally, it ma...
MySQL: selecting rows where a column is null
...for a certain column, it returns an empty set. However, when I look at the table in phpMyAdmin, it says null for most of the rows.
...
How to get current date & time in MySQL?
...ccepted answers, I think this way is also possible:
Create your 'servers' table as following :
CREATE TABLE `servers`
(
id int(11) NOT NULL PRIMARY KEY auto_increment,
server_name varchar(45) NOT NULL,
online_status varchar(45) NOT NULL,
_exchange varchar(45) NOT NULL,
...
How to escape apostrophe (') in MySql?
...y be written as “''”.
(Also, you linked to the MySQL 5.0 version of Table 8.1. Special Character Escape Sequences, and the current version is 5.6 — but the current Table 8.1. Special Character Escape Sequences looks pretty similar.)
I think the Postgres note on the backslash_quote (string)...
SELECT * WHERE NOT EXISTS
...
You didn't join the table in your query.
Your original query will always return nothing unless there are no records at all in eotm_dyn, in which case it will return everything.
Assuming these tables should be joined on employeeID, use the foll...
How to add a footer to a UITableView in Storyboard
...
You can just drag a view to the bottom area of the tableView. You'll see in the hierarchy that it will be a subview of the tableview. You can then drag subviews such as labels and buttons there, adjust the height, etc.
...
Is floating point math broken?
...754 is anything with an error of less than one unit in the last place. The table of reciprocals of Y (1/Y) is known as the quotient selection table (QST) in the slow division, and the size in bits of the quotient selection table is usually the width of the radix, or a number of bits of the quotient ...