Amazon Redshift
Database Developer Guide

|| (Concatenation) Operator

Concatenates two strings on either side of the || symbol and returns the concatenated string.

Similar to CONCAT.


For both the CONCAT function and the concatenation operator, if one or both strings is null, the result of the concatenation is null.


string1 || string2


string1, string2

Both arguments can be fixed-length or variable-length character strings or expressions.

Return Type

The || operator returns a string. The type of string is the same as the input arguments.


The following example concatenates the FIRSTNAME and LASTNAME fields from the USERS table:

select firstname || ' ' || lastname from users order by 1 limit 10; ?column? ----------------- Aaron Banks Aaron Booth Aaron Browning Aaron Burnett Aaron Casey Aaron Cash Aaron Castro Aaron Dickerson Aaron Dixon Aaron Dotson (10 rows)

To concatenate columns that might contain nulls, use the NVL Expression expression. The following example uses NVL to return a 0 whenever NULL is encountered.

select venuename || ' seats ' || nvl(venueseats, 0) from venue where venuestate = 'NV' or venuestate = 'NC' order by 1 limit 10; seating ----------------------------------- Ballys Hotel seats 0 Bank of America Stadium seats 73298 Bellagio Hotel seats 0 Caesars Palace seats 0 Harrahs Hotel seats 0 Hilton Hotel seats 0 Luxor Hotel seats 0 Mandalay Bay Hotel seats 0 Mirage Hotel seats 0 New York New York seats 0