Search code examples
sqlgreenplum

using concat function in sql

Sample data

 yearmon
 Jul-2017
 Aug-2017
 Sep-2017
 Jan-2018
 Jul-2018

I want to add '15' for yearmon column .

I have tried using concat function but it doesnt work.

Expected 

  yearmon
 15-Jul-2017
 15-Aug-2017
 15-Sep-2017
 15-Jan-2018
 15-Jul-2018
Solution

  • The SQL Standard has an operator for concatenation, which is easy to understand and quick to type. You just use the || operator, just like you'd use a + for integers:

    SELECT '15-' || yearmon AS full_date FROM table;

    concat function is calling || operator internally. concat function will be called as following.

    SELECT concat ('15-', yearmon) AS full_date FROM table;
SELECT concat_ws ('-', '15', yearmon) AS full_date FROM table;