select to select in sql code example

Example 1: sql update select

UPDATE
    Table_A
SET
    Table_A.col1 = Table_B.col1,
    Table_A.col2 = Table_B.col2
FROM
    Some_Table AS Table_A
    INNER JOIN Other_Table AS Table_B
        ON Table_A.id = Table_B.id
WHERE
    Table_A.col3 = 'cool'

Example 2: 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 3: sql select

Used to select data from a database, which is then returned in a results set.
Example 1: Selects all columns from all users.
SELECT * FROM users;
Example 2: Selects the first_name and surname columns
from all users.xx
SELECT first_name, surname FROM users;

Example 4: select in select sql

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

Example 5: select in select sql

SELECT column-names  FROM table-name1 WHERE value IN (SELECT column-name                   FROM table-name2                   WHERE condition)