mysql - 複数のテーブルを結合して 1 つのテーブルを作成する

Question

Advance、Transport、Medicine という 3 つのテーブルがあります。これらの 3 つのテーブルを結合して、emp_id 1 の最後のテーブルのようなテーブルを作成したいと考えています。dql (教義) または SQL を使用して SQL レベルでこれを行うことは可能ですか?

Answer 1

CREATE TABLE NewTable
SELECT  Date, 
        Emp_ID,
        Amount As Advance, 
        NULL AS Transport,
        NULL AS Medicine
FROM    Advance
WHERE   Emp_ID = 1           -- remove this WHERE clause to include all emp_ID
UNION   ALL
SELECT  Date, 
        Emp_ID,
        NULL As Advance, 
        Amount AS Transport,
        NULL AS Medicine
FROM    Transport
WHERE   Emp_ID = 1           -- remove this WHERE clause to include all emp_ID
UNION   ALL
SELECT  Date, 
        Emp_ID,
        NULL As Advance, 
        NULL AS Transport,
        Amount AS Medicine
FROM    Medicine
WHERE   Emp_ID = 1           -- remove this WHERE clause to include all emp_ID

• CREATE TABLE...SELECT 構文

VIEWこの上に を作成することもできます。

CREATE VIEW EmployeeView
AS
SELECT  Date, 
        Emp_ID,
        Amount As Advance, 
        NULL AS Transport,
        NULL AS Medicine
FROM    Advance
WHERE   Emp_ID = 1           -- remove this WHERE clause to include all emp_ID
UNION   ALL
SELECT  Date, 
        Emp_ID,
        NULL As Advance, 
        Amount AS Transport,
        NULL AS Medicine
FROM    Transport
WHERE   Emp_ID = 1           -- remove this WHERE clause to include all emp_ID
UNION   ALL
SELECT  Date, 
        Emp_ID,
        NULL As Advance, 
        NULL AS Transport,
        Amount AS Medicine
FROM    Medicine
WHERE   Emp_ID = 1           -- remove this WHERE clause to include all emp_ID

• ビューの作成構文