Description: ‘All’ is a keyword used in SQL (Structured Query Language) that allows selecting all records from a table in a query. This instruction is fundamental for data manipulation and retrieval in relational databases. By using ‘SELECT *’, the user can obtain all columns and rows from a specific table, which is useful for gaining a comprehensive view of the stored data. This functionality is especially valuable in situations where an exhaustive analysis of the information is required, as it allows developers and data analysts to work with complete datasets without needing to specify each individual column. However, it is important to use this instruction with caution, as it may result in retrieving large volumes of data, which could affect query performance and system efficiency. In summary, ‘all’ is a powerful tool in SQL that facilitates interaction with databases, allowing for broader exploration and analysis of the available information.
Examples: An example of using ‘all’ in SQL would be the query ‘SELECT * FROM employees;’, which retrieves all records from the ’employees’ table.
