Here are five of the most commonly used SQL queries in data science:

1. SELECT and FROM Clauses
- Basic data retrieval: SELECT column1, column2 FROM table_name;

2. WHERE Clause
- Filtering data: SELECT * FROM table_name WHERE condition;

3. GROUP BY and Aggregate Functions
- Summarizing data: SELECT column1, COUNT(*), AVG(column2) FROM table_name GROUP BY column1;

4. JOIN Operations
- Combining data from multiple tables:

     SELECT a.column1, b.column2
     FROM table1 a
     JOIN table2 b ON a.common_column = b.common_column;
     

5. Subqueries and Nested Queries
- Advanced data retrieval:

     SELECT column1
     FROM table_name
     WHERE column2 IN (SELECT column2 FROM another_table WHERE condition);