[size=medium][align=center][b]Generating Summaries[/b][/align][/size]
[size=small][b]1.Using DISTINCT to Eliminate Duplicates[/b][/size]
select count(DISTINCT name) from driver_log;
count(DISTINCT name) 多少个不同的名字。
[size=small][b]1.Using DISTINCT to Eliminate Duplicates[/b][/size]
select count(DISTINCT name) from driver_log;
count(DISTINCT name) 多少个不同的名字。
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