SQLite 选择两列作为一列与 Null

Question

如果其中一列有 Null，我将如何组合这两列？

SELECT (column1 || " " || column2) AS expr1 FROM your_table;

我希望输出是：

Answer 1

SELECT (COALESCE(column1,'') || " " || COALESCE(column2, '')) AS expr1 FROM your_table;