Combine STRING on ORACLE

We could append String on ORACLE by ‘||’.

Examples Statement:

SELECT ‘Vietnam’ || ‘ ‘ || ‘ is beautiful’ AS “My country” FROM DUAL;

Examples Statement:

SELECT FIRST_NAME || ‘ ‘ || LAST_NAME AS “NAME” FROM EMPLOYEES;

We could use CONCAT(String1, String2) to append String. CONCAT function has two parameter, so when you want to combine more than 2 String, we need to use nest statements. For statements above, we could write them again:

SELECT CONCAT(‘Vietnam’, CONCAT(‘ ’, ‘is beautiful’))  FROM DUAL;

SELECT CONCAT(FIRST_NAME, CONCAT(‘ ’, LAST_NAME))  AS “NAME” FROM EMPLOYEES;