在Concat mysql中选择

Question

I'm trying to get a date value with: - Current year - Current month - Day number from one select

the query

SELECT rat_data FROM rate_unita WHERE rateid = 1 

as a result one INT value.

When I try to execute the following:

SELECT DATE(CONCAT(YEAR(NOW())),(MONTH(NOW())), (SELECT rat_data FROM rate_unita WHERE rateid = 1))

Mysql mark my syntax as incorrect near ' ( MONTH( NOW( ) ) ) , ( SELECT rat_data FROM rate_unita WHERE r

I think that there is something wrong with the way I'm calling the SELECT in the CONCAT, what is the correct query to reach my goal?

Thanks L

Answer 1

You're closing the concat function too early. Remove some extra parentheis

SELECT DATE(CONCAT(YEAR(NOW()),
  MONTH(NOW()),
  (SELECT rat_data FROM rate_unita WHERE rateid = 1)
))

But you need to add some hyphens to make it a true date value

SELECT DATE(
  CONCAT(
    YEAR(NOW()),
    '-',
    MONTH(NOW()),
    '-',
    (SELECT rat_data FROM rate_unita WHERE rateid = 1)
  )
)

This should result in a date of YEAR-MONTH-rat_data

Here's a working SQL Fiddle

Answer 2

Use DATE_FORMAT function. Here are a few examples: http://www.w3schools.com/sql/func_date_format.asp http://www.mysqltutorial.org/mysql-date_format/