HIM-650: Health Care Data Management (Data Manipulation and Querying with SQL

Data Manipulation and Querying with SQL In June 1970, Dr. E. F. Codd published the paper, “A Relational Model of Data for Large Shared Data Banks", in the Association of Computer Machinery (ACM) journal, Communications of the ACM (Lorentz & Gregoire, 2003). IBM used Codd’s findings when they started working on a new language for relational database management. Originally the language was called Structured English Query Language (SEQUEL). The project had a few implementations and revisions, and the language changed several times. The final name for the language is SQL, which is still used today. SQL/DS (1981) and DB2 (1983) are some of the commercial products developed by IBM. Other vendors including Oracle, Sybase and Ingres announced their own commercial SQL-based products (Pickett, 2020). SQL is a specialized programming language that is used for managing relational databases and performing different operations on that data. SQL has many uses to include modifying database tables and index structures. SQL is used to add, update, and delete rows of data within a database. The retrieval of different subsets of information in a database for transaction processing and analytics applications is also done in SQL (Boyini, 2018). There are two main sets of commands that are used to create and modify databases in SQL. The first set of commands are Data Definition Language, and they are used to develop and delete databases and its objects. The second set of commands are Data Manipulation Language and these are used to insert, modify, and delete data stored in a database (IAC Publishing, 2020). SQL functions are sub-programs that are commonly used throughout SQL database applications. These functions are used for processing and manipulation data. SQL functions may have zero or more input parameters but can return only one value. The simplest way to classify SQL functions is to divide them into built-in functions and user-defined functions. The built-in 2 functions are standard functions that are already provided by the SQL database system. ANSI (American National Standards Institute) SQL standards defines most of the built-in functions. These built-in functions can be divided further into aggregate functions or scalar functions. User defined functions, however, are functions that are created by the user for a specific purpose. The user-defined functions can either return a single value or a set of values. There are many advantages of using functions. A function needs to be written only once and can be reused multiple times. This saves time and effort and supports modular programming. Functions improve performance and efficiency of the database. SQL functions are compiled and cached before use. Complex programming logic can be decomposed into a number of smaller and simpler functions, thus making it easier to understand and maintain (What are SQL Functions? - Use