SQL LEFT JOIN

SQL using RIGHT JOIN.

  • LEFT JOIN - Return all rows from the left table, even if there are no matches in the right table of two tables joined.

    Pictorial representation :

  • LEFT JOIN and LEFT OUTER JOIN are the same.
  • A skeleton version of LEFT JOIN syntax is this:
    SELECT select_list
    FROM table_1 LEFT [OUTER] JOIN table_2
    ON [table_1.]column  join_operator  [table_2.]column
    [WHERE search_conditions ]
    [ORDER BY column1, column2, ... ]
    Example using LEFT JOIN between the tables:
    SQL server, MySQL, Oracle, PostgreSQL :
    Select a.US_STATE_CD "Addresses code", ADDR_LINE "Address",
            CITY, u.US_STATE_CD "State code", US_STATE_NM 
     from US_STATES u
     LEFT OUTER JOIN ADDRESSES a
     ON a.US_STATE_CD=u.US_STATE_CD
    WHERE US_STATE_NM LIKE 'A%'
    ORDER BY u.US_STATE_CD;
    The result should be:
    Addresses code Address city State code us_state_nm
    AK Alaska
    AL Alabama
    AR 3009 Table Rock Road Biglerville Alleene AR Arkansas
    AR 3009 Table Rock Road Biglerville Alleene AR Arkansas
    AZ Arizona
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