需要从数字数据类型列 (123456789) 获取日期格式 (YYYY-MM-DD)

Question

I have a column with datatype NUMBER(32,0) . This column actually stores the date and time stamp from the application.

I need to export this number data type column as date .

ie,

select column_name from table_name;

 o/p:
1368046452000

I tried this option to export as Date,

SELECT TO_DATE( 
         TO_TIMESTAMP('1970-01-01'
                     ,'YYYY-MM-DD'
         ) + NUMTODSINTERVAL(column_name/1000, 'SECOND')
        ,'YYYY-MM-DD')
FROM  table_name;

It gives me the output "15-JUL-23" as expected.

Question:

This table has around 900+ columns and in which 50+ columns are like this number data_type which stored the date and time in it. I need to convert/format these 50+ columns into YYYY-MM-DD .

How can I get/export/select all the column values from the table in which the above number data_type columns should return with YYYY-MM-DD format?

Please help!!

Thanks, Karthik

Answer 1

Your time appears to the a Unix timestamp which will measure milliseconds since 1970-01-01 in the UTC time zone.

You can use:

SELECT TIMESTAMP '1970-01-01 00:00:00 UTC' + column_name * INTERVAL '0.001' SECOND
FROM   table_name;

Which will get the value as a TIMESTAMP data type (since it can have fractional seconds).

If you want it as a DATE then use CAST to convert it:

SELECT CAST(
         TIMESTAMP '1970-01-01 00:00:00 UTC' + column_name * INTERVAL '0.001' SECOND
         AS DATE
       )
FROM   table_name;

If you want it in a specific time zone (and not UTC) then use AT TIME ZONE 'your_tz' :

SELECT CAST(
         ( TIMESTAMP '1970-01-01 00:00:00 UTC' + column_name * INTERVAL '0.001' SECOND )
           AT TIME ZONE 'PST'
           AS DATE
       )
FROM   table_name;

So for your test data:

CREATE TABLE table_name ( column_name ) AS
SELECT 1368046452000 FROM DUAL;

the query:

SELECT ( TIMESTAMP '1970-01-01 00:00:00 UTC' + column_name * INTERVAL '0.001' SECOND )
         AS UTC_TIMESTAMP,
       CAST(
         ( TIMESTAMP '1970-01-01 00:00:00 UTC' + column_name * INTERVAL '0.001' SECOND )
           AS DATE
       ) AS UTC_DATE,
       CAST(
         ( TIMESTAMP '1970-01-01 00:00:00 UTC' + column_name * INTERVAL '0.001' SECOND )
           AT TIME ZONE 'PST'
           AS DATE
       ) AS PST_DATE
FROM   table_name;

would output:

 UTC_TIMESTAMP |  UTC_DATE |  PST_DATE:-------------------------------- |:------------------ |:------------------ 2013-05-08 20:54:12.000000000 UTC |  2013-05-08 20:54:12 |  2013-05-08 13:54:12 

db<>fiddle here

Answer 2

Just for heck of less coding, create a function

Create or replace function MyConvert(p_val in number ) return varchar2
as
begin
    return TO_CHAR(TO_DATE('1970/01/01 00:00:00', 'YYYY/MM/DD HH24:MI:SS') + 
                NUMTODSINTERVAL(p_val / 1000,'SECOND'), 'YYYY-MM-DD');
end;

And then in your code just do

SELECT MyConvert(col1) col1, ..... MyConvert(col50) col50 FROM table

The "date format" you are getting is not actually a date - this is a string representation of the date