PL/SQL stands for Procedural Language extension of SQL. PL/SQL is a combination of SQL along with the procedural features of programming languages. It was developed by Oracle Corporation in the early ...

SELECT SUBSTR('Oracle SQL', 1, 6); -- → Oracle (start at 1, take 6 chars) SELECT SUBSTR('Oracle SQL', 8, 3); -- → SQL (start at 8, take 3 chars) SELECT SUBSTR('Oracle SQL', 8); -- → SQL (start at 8, ...

-- INTEGER / INT → whole numbers, no decimals (e.g. 1, 42, -7) -- Oracle: NUMBER(p) PostgreSQL: INTEGER ← different! -- NUMBER(p, s) → Oracle type: p = total ...