input

What kind of a type is char(n)?
fixed-length character string with user-specified length n
What kind of a type is varchar(n)?
variable-length character string with user-specified maximum length n
What kind of a type is int?
integer
What kind of a type is smallint?
small integer
What kind of a type is numeric(p, d)?
fixed-point number with user-specified precision.
What kind of a type are real and double precision?
floating-point and double-precision floating-point numbers with machine-dependent precision
What kind of a type is float(n)?
floating-point number, with precision of at least n digits.
What is a null value?
a value that indicates an absent value that may exist but be unknown or that may not exist at all
What does create table command do?
define an SQL relation
What does insert command do?
load data into the relation
What does delete command do?
delete tuples from a relation
What does drop table command do?
remove a relation from an SQL database
What does alter table command do?
add attributes to an existing relation