我有来自不同日子的同一个数据库的两个实例。一天中的所有表称为 tableA*，而另一天的所有表称为 tableB*。我想比较数据，看看发生了什么变化。我想选择所有不完全匹配的行。因此，例如，如果表 tableA1 和 tableB1 中的一个值不同，我想从表 A 中选择相应的行并将其标记为“新”，然后从表 B 中将其标记为“已删除”。我试过这样的查询：
SELECT 'new', ta1.name, ta2.name, ta3.name, ta4.name, ta5.name
FROM tableA1 ta1
LEFT JOIN tableA2 ta2 ON ta1.ta2_id = ta2.id
LEFT JOIN tableA3 ta3 ON ta1.ta3_id = ta3.id
LEFT JOIN tableA4 ta4 ON ta1.ta4_id = ta4.id
LEFT JOIN tableA5 ta5 ON ta5.ta1_id = ta1.id WHERE NOT EXISTS
(SELECT tb1.name, tb2.name, tb3.name, tb4.name, tb5.name
FROM tableB1 tb1
LEFT JOIN tableB2 tb2 ON tb1.tb2_id = tb2.id
LEFT JOIN tableB3 tb3 ON tb1.tb3_id = tb3.id
LEFT JOIN tableB4 tb4 ON tb1.tb4_id = tb4.id
LEFT JOIN tableB5 tb5 ON tb5.tb1_id = tb1.id WHERE
tb1.name = ta1.name AND
tb2.name = ta2.name AND
tb3.name = ta3.name AND
tb4.name = ta4.name AND
tb5.name = ta5.name)
UNION
SELECT 'deleted', tb1.name, tb2.name, tb3.name, tb4.name, tb5.name
FROM tableB1 tb1
LEFT JOIN tableB2 tb2 ON tb1.tb2_id = tb2.id
LEFT JOIN tableB3 tb3 ON tb1.tb3_id = tb3.id
LEFT JOIN tableB4 tb4 ON tb1.tb4_id = tb4.id
LEFT JOIN tableB5 tb5 ON tb5.tb1_id = tb1.id WHERE NOT EXISTS
(SELECT ta1.name, ta2.name, ta3.name, ta4.name, ta5.name
FROM tableA1 ta1
LEFT JOIN tableA2 ta2 ON ta1.ta2_id = ta2.id
LEFT JOIN tableA3 ta3 ON ta1.ta3_id = ta3.id
LEFT JOIN tableA4 ta4 ON ta1.ta4_id = ta4.id
LEFT JOIN tableA5 ta5 ON ta5.ta1_id = ta1.id WHERE
tb1.name = ta1.name AND
tb2.name = ta2.name AND
tb3.name = ta3.name AND
tb4.name = ta4.name AND
tb5.name = ta5.name)
希望如果我创建相同的结构并比较所有值，我会得到预期的结果。即使数据库相同，我也会选择很多行。