Saturday, February 8, 2014

9.Columns And Rows


Columns :
       column is a set of data values of a particular simple type
       When you create a table  its each columns have a column name, a valid data type, and a width
       A table has a specified number of columns  specified by the user.
       Different Constraints are applied to the columns while the creation of the tables
       Eg: not null,unique,primary key , foreign key constraint …
       We can use any one of these Constraints in the columns
ROWS
Ø  A Table have any number of rows defined as a tuple or a record.
Ø  A database record is a row of data in a database table
Ø  Each Rows have unique Row id
Every rows in the table has the same structure

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