Intro Relational Database - Queries

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Consider the following relational database Employee SSN Lastname Firstname Age Participation Emp Proj Project CodeTitle Cost Jack Jackie Niki Alberto Brabham 88 Stewart Lauda Ascari 78 68 36 Moon120 Mars 140 Jupyter 140 Venus 140 4 Formulate queries that find: 1. 2. 3. 4. In relational algebra: the lastname of employees working on the Mars project In SQL: the age of employees working on the Mars project In SQL: the projects with only one employee, showing the project code In relational algebra: the projects with only one employee, showing the codes of the projects and the lastnames of the employees