换个写法数一遍
不取内容,只数个数:
这个数字是多少?
mysql> SELECT COUNT(*) FROM learning_record WHERE user_id = 101;
+----------+
| COUNT(*) |
+----------+
| 3 |
+----------+
mysql>
不取内容,只数个数:
这个数字是多少?
mysql> SELECT COUNT(*) FROM learning_record WHERE user_id = 101;
+----------+
| COUNT(*) |
+----------+
| 3 |
+----------+
mysql>
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