CONCAT

Concatenates two strings and returns a varchar data type. If either argument is null, concat returns null.

Syntax

CONCAT ('string-expression1, string-expression2)

Behavior type

Arguments

string-expression1, string-expression2

The values to concatenate, any data type that can be cast to a string value.

Examples

The following examples use a sample table named alphabet with two varchar columns:

=> CREATE TABLE alphabet (letter1 varchar(2), letter2 varchar(2));
CREATE TABLE
=> COPY alphabet FROM STDIN;
Enter data to be copied followed by a newline.
End with a backslash and a period on a line by itself.
>> A|B
>> C|D
>> \.
=> SELECT * FROM alphabet;
 letter1 | letter2
---------+---------
 C       | D
 A       | B
(2 rows)

Concatenate the contents of the first column with a character string:

=> SELECT CONCAT(letter1, ' is a letter') FROM alphabet;
    CONCAT
---------------
 A is a letter
 C is a letter
(2 rows)

Concatenate the output of two nested CONCAT functions:

=> SELECT CONCAT(CONCAT(letter1, ' and '), CONCAT(letter2, ' are both letters')) FROM alphabet;
          CONCAT
--------------------------
 C and D are both letters
 A and B are both letters
(2 rows)

Concatenate a date and string:

=> SELECT current_date today;
   today
------------
 2021-12-10
(1 row)

=> SELECT CONCAT('2021-12-31'::date - current_date, ' days until end of year 2021');
             CONCAT
--------------------------------
 21 days until end of year 2021
(1 row)