A comment is text that the PL/SQL compiler ignores. Its primary purpose is to document code, but you can also disable obsolete or unfinished pieces of code by turning them into comments. PL/SQL has both single-line and multiline comments.
Turns the rest of the line into a single-line comment. Any text that wraps to the next line is not part of the comment.
Begins a comment, which can span multiple lines.
Ends a comment.
A single-line comment can appear within a statement, at the end of a line. A single-line comment can appear inside a multiline comment.
Caution:Do not put a single-line comment in a PL/SQL block that will be processed dynamically by an Oracle Precompiler program. The Oracle Precompiler program ignores end-of-line characters, which means that a single-line comment will end at the end of the block.
A multiline comment can appear anywhere except within another multiline comment.