you can rename a table or a column temporarily by giving another name, which is known as alias. the use of table aliases means to rename a table in a particular sqlite statement. renaming is a temporary change and the actual table name does not change in the database.
the column aliases are used to rename a table's columns for the purpose of a particular sqlite query.
syntax
following is the basic syntax of table alias.
select column1, column2.... from table_name as alias_name where [condition];
following is the basic syntax of column alias.
select column_name as alias_name from table_name where [condition];
example
consider the following two tables, (a) company table is as follows −
sqlite> select * from company; id name age address salary ---------- -------------------- ---------- ---------- ---------- 1 paul 32 california 20000.0 2 allen 25 texas 15000.0 3 teddy 23 norway 20000.0 4 mark 25 rich-mond 65000.0 5 david 27 texas 85000.0 6 kim 22 south-hall 45000.0 7 james 24 houston 10000.0
(b) another table is department as follows −
id dept emp_id ---------- -------------------- ---------- 1 it billing 1 2 engineering 2 3 finance 7 4 engineering 3 5 finance 4 6 engineering 5 7 finance 6
now, following is the usage of table alias where we use c and d as aliases for company and department tables respectively −
sqlite> select c.id, c.name, c.age, d.dept
from company as c, department as d
where c.id = d.emp_id;
the above sqlite statement will produce the following result −
id name age dept ---------- ---------- ---------- ---------- 1 paul 32 it billing 2 allen 25 engineering 3 teddy 23 engineering 4 mark 25 finance 5 david 27 engineering 6 kim 22 finance 7 james 24 finance
consider an example for the usage of column alias where company_id is an alias of id column and company_name is an alias of name column.
sqlite> select c.id as company_id, c.name as company_name, c.age, d.dept
from company as c, department as d
where c.id = d.emp_id;
the above sqlite statement will produce the following result −
company_id company_name age dept ---------- ------------ ---------- ---------- 1 paul 32 it billing 2 allen 25 engineering 3 teddy 23 engineering 4 mark 25 finance 5 david 27 engineering 6 kim 22 finance 7 james 24 finance