A SQL query requests data from the database and receives the results. This process, also known as data retrieval, is expressed using the select statement. You can use it for selections, which retrieve a subset of the rows in one or more tables, and you can use it for projections, which retrieve a subset of the columns in one or more tables.
A simple example of a select statement is:
select select_list from table_list where search_conditions
The select clause specifies the columns you want to retrieve. The from clause specifies the tables to search. The where clause specifies which rows in the tables you want to see. For example, the following select statement finds the first and the last names of writers living in Oakland from the authors table, in the pubs2 database.
select au_fname, au_lname from authors where city = "Oakland"
Results of this query appear in columnar format:
au_fname au_lname -------------- ----------- Marjorie Green Dick Straight Dirk Stringer Stearns MacFeather Livia Karsen (5 rows affected)
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