? Concatenate Strings in SQL

Concatenation means joining two or more strings together to form a single string.

? Common Ways to Concatenate in Different SQL Databases

? Examples

Using CONCAT() (MySQL, PostgreSQL, SQL Server 2012+)

SELECT CONCAT(first_name, ' ', last_name) AS full_name FROM employees;

Using || Operator (PostgreSQL, Oracle)

SELECT first_name || ' ' || last_name AS full_name FROM employees;

Using + Operator (SQL Server)

SELECT first_name + ' ' + last_name AS full_name FROM employees;

? Notes

• CONCAT() can take multiple arguments.

• When concatenating NULL with a string:

  • CONCAT() treats NULL as an empty string.

  • Using || or + operator may return NULL if any operand is NULL (depends on DBMS).

• Use functions like COALESCE() to handle NULL values when concatenating.

If you want examples specific to a database system or handling NULLs in concatenation, just ask!