select query in sql code example

Example 1: sql select syntax

select [all/distinct] <COL1>, <COL2>, <COL3>
from <TABLE_NAME>
[join <JOIN_CONDITION>]
[where <CONDITION>]
[group by <COLUMN_NAME>]
[having <SEARCH_CONDITION>]
[order by <SORT_SPECIFICATION>]


/*
Specifically for SQL -> Oracle

LEGEND: 
[...]   :   optional entries
<...>   :   your specific entry
*/

Example 2: how select from db

SELECT columname FROM tablename

Example 3: return columns from table sql

SELECT *
FROM INFORMATION_SCHEMA.COLUMNS -- INFORMATION_SCHEMA is an ANSI-standard (American National Standard Institute) set of read-only views which provide information about all of the tables, views, columns, and procedures in a database
WHERE TABLE_NAME = N'Customers' -- "N" defines the subsequent string (the string after the N) as being in unicode

Example 4: select query in sql

SELECT column_name FROM table_name;

Example 5: select in select sql

SELECT column1 = (SELECT column-name FROM table-name WHERE condition),       column-names  FROM table-name WEHRE condition

Example 6: sql select statement

Projection = Select the columns in
a table that are returned by a query
Selection = Selects the rows in a
table that are returned by a query
Join = Brings together data that is 
stored in different tables by
specifying the link between them