A constraint is a rule that is applied to a column in a table to ensure that the data in the column meets certain requirements. There are several types of constraints in SQL, including NOT NULL, UNIQUE, PRIMARY KEY, FOREIGN ...Read more
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A view is a virtual table that is created based on the result of a query, while a table is a physical object that stores data in a database. Views are used to provide a customized view of the data ...Read more
A foreign key is a column or set of columns in a table that refers to the primary key of another table. It is used to establish a relationship between two tables.When we study databases, one important idea is how ...Read more
What is a primary key?When we work with databases, one of the first ideas we must understand is how to uniquely identify each record. Just like every student in a class has a unique roll number, every row in a ...Read more
No, JSON does not support comments. According to the official JSON specification, comments are not allowed in JSON files. Any comments included in a JSON file will result in a syntax error when the file is parsed. However, you can ...Read more