Another kind of key used is the foreign key which is created when a particular column from one table is actually referencing the column of another table. This primary key should be unique for each row or record of the table and can be made up of single or multiple columns grouped together. Note: Along with all the terms used in the above syntax, you can even make the use of primary keys, which can be auto-incremented and will work as an identifier to recognize an individual row from the multiple rows of the table. Name of the table – This is the table name that you want to create in which you will store the data in row-column format.When not specified, the default value of this constraint is considered as NULL. By specifying this constraint, we can have control over whether the NULL values be stored inside the column or not. NOT NULL | NULL – This constraint can be applied to the individual columns and is optional in nature.Datatype – The datatype can be NUMBER, VARCHAR, BOOLEAN, DATE, TIMESTAMP, DATETIME, etc., which will represent what type of value will be stored in this column of the table.The column names should be short and meaningful so that you can easily understand from the name itself the purpose and type of column created for storing values. Name of the column – This is the column name that will define which attribute value you want to store in that column.
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