stno name addr city state zip
1011 Edwards P. David 10 Red Rd. Newton MA 02159
2415 Grogan A. Mary 8 Walnut St. Malden MA 02148
2661 Mixon Leatha 100 School St. Brookline MA 02146
2890 McLane Sandy 30 Cass Rd. Boston MA 02122
3442 Novak Roland 42 Beacon St. Nashua NH 03060
3566 Pierce Richard 70 Park St. Brookline MA 02146
4022 Prior Lorraine 8 Beacon St. Boston MA 02125
5544 Rawlings Jerry 15 Pleasant Dr. Boston MA 02115
5571 Lewis Jerry 1 Main Rd Providence RI 02904
6410 Davis Richard 45 Algonquin Rd. Natick MA 01760
7209 Chu Martin 90 Rye Dr. Ayer MA 01290
INSTRUCTORS
empno name rank roomno telno
019 Evans Robert Professor 82 7122
023 Exxon George Professor 90 9101
056 Sawyer Kathy Assoc. Prof. 91 5110
126 Davis William Assoc. Prof. 72 5411
234 Will Samuel Assist.Prof. 90 7024
323 Campbell Kenneth Professor 102 7077
Figure 5.1: Tables with tuples with null components
94 SQL — The Relational Language
stno name
---------------------------
1011 Evans Robert
2415 Evans Robert
2661 Exxon George
2890 Exxon George
5544 Exxon George
3442 Sawyer Kathy
3566 Davis William
4022 Will Samuel
5571 Will Samuel
Campbell Kenneth
Finally, the outer join itself can be computed using the operator outer join: