SQL JOINS結合

2600 ワード
OuterJoin sql selfjoin leftjoin サイン JOIN RIGHTJOIN テキストリンク
● LEFT JOIN
A
SELECT <FIELD_LIST> 
FROM TABLEA A LEFT JOIN TABLEB B
ON A.PKEY = B.PKEY
A-B
SELECT <FIELD_LIST> 
FROM TABLEA A LEFT JOIN TABLEB B
ON A.PKEY = B.PKEY
WHERE B.PKEY IS NULL
● RIGHT JOIN
B
SELECT <FIELD_LIST> 
FROM TABLEA A RIGHT JOIN TABLEB B
ON A.PKEY = B.PKEY
B-A
SELECT <FIELD_LIST> 
FROM TABLEA A RIGTH JOIN TABLEB B
ON A.PKEY = B.PKEY
WHERE B.PKEY IS NULL
● OUTER JOIN
A∪B
SELECT <FIELD_LIST>
FROM TABLEA A FULL OUTER JOIN TABLEB B
ON A.PKEY = B.PKEY
A≒B−(A∏B):A≒BからA,Bの主キー部分を取り除く
SELECT <FIELD_LIST>
FROM TABLEA A FULL OUTER JOIN TABLEB B
ON A.PKEY = B.PKEY
WHERE A.PKEY IS NULL
AND B.PKEY IS NULL
● SELF JOIN
A∩B
SELECT <FIELD_LIST>
FROM TABLEA A INNER JOIN TABLEB B
ON A.PKEY = B.PKEY
牙列缺损
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