mysql COALESCE

COALESCE函数在MySQL中用于返回参数列表中的第一个非空值。如果所有参数都为空，则返回NULL。其语法如下：COALESCE(val1, val2, ..., valN)，其中val1、val2到valN表示可选的多个参数，函数会从左到右依次检查这些参数是否为空，然后返回第一个非空值。该函数在MySQL中也可以用来替代Oracle中的nvl函数，其使用方法类似，可以传入多个参数。<em>1</em><em>2</em><em>3</em>
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- *1* [如何在 MySQL 中使用 COALESCE 函数](https://blog.csdn.net/weixin_65846839/article/details/131322142)[target="_blank" data-report-click={"spm":"1018.2226.3001.9630","extra":{"utm_source":"vip_chatgpt_common_search_pc_result","utm_medium":"distribute.pc_search_result.none-task-cask-2~all~insert_cask~default-1-null.142^v92^chatsearchT0_1"}} ] [.reference_item]
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- *3* [mysql coalesce](https://blog.csdn.net/u010365819/article/details/106556467)[target="_blank" data-report-click={"spm":"1018.2226.3001.9630","extra":{"utm_source":"vip_chatgpt_common_search_pc_result","utm_medium":"distribute.pc_search_result.none-task-cask-2~all~insert_cask~default-1-null.142^v92^chatsearchT0_1"}} ] [.reference_item]
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