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  • SQL UNION ALL

    QL UNION ALL is query that allows you to select related information from 2 tables, the result is different from the UNION statement. It return all the record from SELECT statement that used.

    UNION ALL selects all rows from each table and combines them into a single table.

    The syntax is as follows:

    SELECT [COLUMN NAME 1], [COLUMN NAME 2],… FROM [TABLE NAME 1]
    UNION ALL
    SELECT [COLUMN NAME 1], [COLUMN NAME 2],… FROM [TABLE NAME 2]


    EXAMPLE :

    We have 2 table name GamesScores, GameScores_new.

    Table GameScores

    PlayerName Department Scores
    Jason IT 3000
    Irene IT 1500
    Jane Marketing 1000
    David Marketing 2500
    Paul HR 2000
    James HR 2000

    Table GameScores_new

    PlayerName Department Scores
    Jason IT 3000
    David Marketing 2500
    Paul HR 2000
    James HR 2000

    SQL statement :

    SELECT PlayerName FROM GameScores
    UNION ALL
    SELECT PlayerName FROM GameScores_new

    Result:

    PlayerName
    Jason
    Irene
    Jane
    David
    Paul
    James
    Jason
    David
    Paul
    James
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  • 原文地址:https://www.cnblogs.com/zhoug2020/p/3327821.html
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