SQL yyyymm date formatting

Question

I have a month column in YYYYMM-Example 201204 format and I need to break it into two column year(2012) and month(04)????

I've tried using Ltrim & Rtrim to break apart but not really working.

Answer 1

This requires string manipulations, which differ by database. A typical method is:

select substr(col, 1, 4) as yyyy, substr(col, 5, 2) as mm

In some databases, the function would be substring() . Most databases support either substr() or substring() .

Answer 2

Try

select yyyy = datepart( year  , t.datetime_column ) ,
       mm   = datepart( month , t.datetime_column ) ,
       ...
from dbo.some_table t

Or

select yyyy = year(  t.datetime_column ) ,
       mm   = month( t.datetime_column ) ,
       ...
from dbo.some_table t

Or, if the column is a string:

select yyyy = convert(int, left(  t.some_column , 4 ) ) ,
       mm   = convert(int, right( t.some_column , 2 ) ) ,
       ...
from dbo.some_table t
where t.some_column like '[0-9][0-9][0-9][0-9][0-9][0-9]'

Answer 3

Assuming Oracle (since none is specified) and varchar/char this would be another option:

select 
    extract(year from (to_date('201204', 'yyyymm'))) year, 
    extract(month from (to_date('201204', 'yyyymm'))) month 
from dual;

First, convert to date and then get the month and year using extract function. Assumes month is always two chars and year four.