The IN operator is a logical operator that allows you to test whether a specified value matches any value in a list.

The following shows the syntax of the SQL Server IN operator:

column | expression IN ( v1, v2, v3, …vn)

In this syntax:

• First, specify the column or expression to test.
• Second, specify a list of values to test. All the values must have the same type as the type of the column or expression.

The SQL Server ALL operator is a logical operator that compares a scalar value with a single-column list of values returned by a subquery.

• The subquery within the parentheses is a Select statement that returns a result of a single column.
• Also, the data type of the returned column must be the same data type as the data type of the scalar expression.

The ALL operator returns TRUE if all the pairs (scalar_expression, v) evaluates to TRUE; v is a value in the single-column result.

If one of the pairs (scalar_expression, v) returns FALSE, then the ALL operator returns FALSE.