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[英]My where statement with a JSON_extract function on a nullable column is confirmed when said column's value is NULL?
[英]WHERE statement with condition when one column is NULL
让我说我有
ID | Column 1 | Column 2
2 | NULL | "a"
3 | "b" | NULL
4 | "c" | "c"
我想写的是:
SELECT ID FROM table, AnotherTable
WHERE (Table.Column1 = AnotherTable.Column IF Table.Column1 IS NOT NULL
OR Table.Column2 = AnotherTable.Column IF Table.Column2 IS NOT NULL)
编辑:我也添加了案例IF Table.Column1 IS NOT NULL和Table.Column2 IS NOT NULL,然后选择Table.Column2 = AnotherTable.Column
您可以使用COALESCE()
函数:
SELECT ID
FROM table JOIN AnotherTable
ON AnotherTable.Column = COALESCE(table.Column1, table.Column2)
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