Oracle 18c

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CREATE TABLE /*HR.*/my_employees (
  id NUMBER,
  first_name VARCHAR2(20),
  last_name VARCHAR2(20),
  userid VARCHAR2(20),
  salary NUMBER
);
INSERT into /*HR.*/my_employees(ID,LAST_NAME,FIRST_NAME,userid,SALARY)
WITH data (id, last_name, first_name, salary) AS (
  SELECT 3, 'Biri', 'Ben', 1100 FROM DUAL UNION ALL
  SELECT 4, 'Newman', 'Chad', 750 FROM DUAL
)
SELECT id,
       last_name,
       first_name,
       SUBSTR(first_name,1,1) || SUBSTR(last_name,1,7),
       salary
FROM   data;
2 rows affected

SELECT * FROM /*HR.*/my_employees;


ID
FIRST_NAME
LAST_NAME
USERID
SALARY


3
Ben
Biri
BBiri
1100

4
Chad
Newman
CNewman
750


ROLLBACK;
INSERT into /*HR.*/my_employees(ID,LAST_NAME,FIRST_NAME,userid,SALARY)
SELECT id,
       last_name,
       first_name,
       SUBSTR(first_name,1,1) || SUBSTR(last_name,1,7),
       salary
FROM   (
  SELECT 3 AS id, 'Biri' AS last_name, 'Ben' AS first_name, 1100 AS salary FROM DUAL
UNION ALL
  SELECT 4, 'Newman', 'Chad', 750 FROM DUAL
);
2 rows affected

SELECT * FROM /*HR.*/my_employees;


ID
FIRST_NAME
LAST_NAME
USERID
SALARY


3
Ben
Biri
BBiri
1100

4
Chad
Newman
CNewman
750