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)