Write a Query First to Alter Table to add a new Column managername to the employee table Write an Update query using Self-Join and Case When/Then to update the managername for the respective employees in the managername column. Where there is no manager present, then the CASE When/Then should update the text ‘No Manager’ in the managername column. [Hint: Jennifer has no Manager, everyone else has a manager]
SQL
SQL stands for Structured Query Language, is a form of communication that uses queries structured in a specific format to store, manage & retrieve data from a relational database.
Queries
A query is a type of computer programming language that is used to retrieve data from a database. Databases are useful in a variety of ways. They enable the retrieval of records or parts of records, as well as the performance of various calculations prior to displaying the results. A search query is one type of query that many people perform several times per day. A search query is executed every time you use a search engine to find something. When you press the Enter key, the keywords are sent to the search engine, where they are processed by an algorithm that retrieves related results from the search index. Your query's results are displayed on a search engine results page, or SER.
- Consider the Table: Employee
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Write a Query First to Alter Table to add a new Column managername to the employee table |
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Write an Update query using Self-Join and Case When/Then to update the managername for the respective employees in the managername column. Where there is no manager present, then the CASE When/Then should update the text ‘No Manager’ in the managername column. [Hint: Jennifer has no Manager, everyone else has a manager]
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