Condition

A condition is made up of one or more expressions combinded with one or more operators

types of expressions

A number

A column in a table or views

A string literal

A built-in function, such as concat('Learning',' ', 'SQL')

A subquery

A list of expressions, such as ('Boston', 'New Yourk', 'Chicago')

types of operators

Comparison operators

=, !=, <, >, <>, like, in, between

Arithmetic operators

+, -, *, /