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THE RELATIONAL DATA BASE (RDB) AND STRUCTURED QUERY LANGUAGE (SQL)

THE RELATIONAL DATA BASE (RDB) AND STRUCTURED QUERY LANGUAGE (SQL). History:. Based on relational theory Relational model first introduced by Dr. E.F Codd in early 70s First prototype system developed by IBM in the mid 70s First commercial version from ORACLE in 1979.

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THE RELATIONAL DATA BASE (RDB) AND STRUCTURED QUERY LANGUAGE (SQL)

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  1. THE RELATIONAL DATA BASE (RDB) AND STRUCTURED QUERY LANGUAGE (SQL) History: • Based on relational theory • Relational model first introduced by Dr. E.F Codd in early 70s • First prototype system developed by IBM in the mid 70s • First commercial version from ORACLE in 1979

  2. THE RELATIONAL DATA BASE (RDB) AND STRUCTURED QUERY LANGUAGE (SQL) Current status: • RDBs are now the standard for data storage • SQL is the standard for accessing and manipulating RDBs • SQL is an ANSI standard in the public domain • SQL is implemented by many vendors including all major data base systems

  3. Description of an RDB: • Data stored in related tables • Tables made up of rows and columns • Rows in are uniquely identified by a primary key • Rows in different tables are related by a foreign key

  4. Description of SQL: • Non-procedural • Works on an entire set of data at a time • Has English like syntax • Very concise and powerful • Combines functionality of the data step and several procedures into a single statement

  5. DNAME LOC DEPTNO ACCOUNTING NEW YORK 10 RESEARCH DALLAS 20 SALES CHICAGO 30 OPERATIONS BOSTON 40 EMPNO ENAME JOB MGR HIREDATE SAL DEPTNO COMM 7369 SMITH CLERK 7902 17DEC80 $800 20 . 7499 ALLEN SALESMAN 7698 20FEB81 $1,600 30 $300 7521 WARD SALESMAN 7698 22FEB81 $1,250 30 $500 7566 JONES MANAGER 7839 02APR81 $2,975 20 . 7654 MARTIN SALESMAN 7698 28SEP81 $1,250 30 $1,400 7698 BLAKE MANAGER 7839 01MAY81 $2,850 30 . 7782 CLARK MANAGER 7839 09JUN81 $2,450 10 . 7788 SCOTT ANALYST 7566 19APR87 $3,000 20 . 7839 KING PRESIDENT . 17NOV81 $5,000 10 . 7844 TURNER SALESMAN 7698 08SEP81 $1,500 30 $0 7876 ADAMS CLERK 7788 23MAY87 $1,100 20 . 7900 JAMES CLERK 7698 03DEC81 $950 30 . 7902 FORD ANALYST 7566 03DEC81 $3,000 20 . 7934 MILLER CLERK 7782 23JAN82 $1,300 10 . A ONE-TO-MANY RELATIONSHIP DEPT Table (Mater table) PK 1 EMP Table (Detail table) * FK PK

  6. STRUCTURE OF SQL SELECT STATEMENT SYNTAX SELECT variable list FROM table list; SELECT variable list FROM table list WHERE condition; SELECT variable list FROM table list WHERE condition ORDER BY variable list; SELECT variable list FROM table list WHERE condition GROUP BY variable list HAVING condition ORDER BY variable list;

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