learning to make sense of the syntax of syntax

Question

i want to use alter table

but the syntax posted here:

http://dev.mysql.com/doc/refman/5.1/en/alter-table.html

is very confusing

i do not understand what the [ ] mean or the { } mean or the pipes

is there some kind of tutorial that can help me understand this?

Answer 1

• The brackets [ ] denote optional expressions
• The pipes mean OR.
• The braces { } group words for the pipes.

For example:

• [COLUMN] means that the word COLUMN can optionally appear
• {INDEX|KEY} means that either INDEX or KEY must appear
• [FIRST | AFTER col_name ] means that the word FIRST or AFTER (the name of a column) can optionally appear