Is a view of one or more tables?
Views in SQL are kind of virtual tables. A view also has rows and columns as they are in a real table in the database. We can create a view by selecting fields from one or more tables present in the database. A View can either have all the rows of a table or specific rows based on certain condition.
What is difference between views and tables?
A table consists of rows and columns to store and organized data in a structured format, while the view is a result set of SQL statements. A table is structured with columns and rows, while a view is a virtual table extracted from a database. The table is an actual or real table that exists in physical locations.
Which is easier to use, one table or two?
If every table has a 1 to 1 relation then one table would be easier to use. There is no need to split the table in that case. Splitting the table sugests that there are more then 1 row, which could lead to a case where another developer would treat them that way.
Which is more efficient : multiple MySQL tables or one large table?
MySQL is capable of using only JOIN method, namely NESTED LOOPS. This means that for each record in the driving table, MySQL locates a matching record in the driven table in a loop.
What should go into a common table with PersonID?
Birth date, height, weight etc.) are candidates to go into a common table with PersonId as the key. The number of attributes in each table should not be of concern at this point. Multi valued attributes such as Hobby need a slightly different treatment.
What should go into a common table in MySQL?
Single valued attributes (eg. Birth date, height, weight etc.) are candidates to go into a common table with PersonId as the key. The number of attributes in each table should not be of concern at this point. Multi valued attributes such as Hobby need a slightly different treatment.