是不是 约等于将选中的多列按照字符串拼接后去重. 不太理解 distinct 多列背后的逻辑
1
zydxn 2021-12-30 14:42:10 +08:00 1
In most cases, a DISTINCT clause can be considered as a special case of GROUP BY.
https://dev.mysql.com/doc/refman/8.0/en/distinct-optimization.html |
2
breadenglish 2021-12-30 14:51:51 +08:00 1
是
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