Why is "BINARY" in a SELECT statement?
The model Votehas validation:
validates_uniqueness_of :topic_id, :scope => [:user_id]
It translates to the following SQL in the development log:
SELECT 1 AS one FROM `votes` WHERE (`votes`.`topic_id` = BINARY 2 AND `votes`.`user_id` = 1) LIMIT 1
Where is there BINARYbefore 2 (topic_id)? And what does it mean?
+5
1 answer
This is an efficient way to compare byte with byte instead of character for character
Example
Suppose you have a database table with a name productsthat has vin_number( column name ) with an entry with a vin_numbersay value123456
Now if you run this
select * from products where vin= '123456'
and
select * from products where vin = '123456 '
Both results will lead to the same result.
Note the space in the second selection
But with a binary comparison
select * from products where vin= BINARY '123456'
or
select * from producst where vin = BINARY '123456 '
Byte byte match is executed as character with character
valid
+7