The difference between 'AND' and '&&' in SQL
AND is Standard SQL
&& is proprietary syntax
For mySQL: The manual is not saying it explicitly, but they are listed as identical:
AND, &&
Logical AND. Evaluates to 1 if all operands are nonzero and not NULL, to 0 if one or more operands are 0, otherwise NULL is returned.
The operator precedence page also makes no distiction.
If you're working with PostgreSQL, '&&' means overlap (have elements in common):
example: ARRAY[1,4,3] && ARRAY[2,1]
https://www.postgresql.org/docs/9.1/static/functions-array.html