Relačná algebra
The syntax of a SELECT statement is:
subselect { UNION [ALL] (subselect) }
[ ORDER BY column [ASC|DESC] {, column [ASC|DESC] } ]
where a subselect has the syntax:
SELECT [ALL|DISTINCT] expression [AS column] {,expression [AS column]}
FROM tablename [corr_name] {, tablename [corr_name] }
[ WHERE search_condition]
[ GROUP BY column {, column} ]
[ HAVING search_condition ]
Note: UNION [ALL] is not supported by Open SQL.
Examples:
select pno, sno from sp;
select x.pno, y.sno from p x, s y
where x.color=’red‘;
select sum(qty), pno
from sp
where sno != ‚s1‘
group by pno;
The syntax of a CREATE TABLE statement is:
CREATE TABLE tablename
[ ( columnname [format] {, columnname [format] } ) ]
[ AS subselect ]
[ WITH with_clause ]
Examples:
create table sample ( col1 integer, col2 varchar(6), col3 float );
create table sample as
select pno, pname, color
from p
where weight > 10;
reate table sample (col1 integer) with journaling;
Additional help is available on ‚datatypes‘ and on SELECT.
