题解 | #查询表总行数#
查询表总行数
https://www.nowcoder.com/practice/c5df013faa764a57aee041f8a043c2c3
SELECT COUNT(*) AS 'cnt' FROM deliver_record;
Q1:为什么是COUNT(*)而不能是COUNT(id)?
查询表总行数
https://www.nowcoder.com/practice/c5df013faa764a57aee041f8a043c2c3
SELECT COUNT(*) AS 'cnt' FROM deliver_record;
Q1:为什么是COUNT(*)而不能是COUNT(id)?
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