mysql - Difference between where and and clause in join sql query -

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what difference between following 2 sql queries

select a.id, a.name, a.country  table  left join table b on a.id = b.id a.name not null

and

select a.id, a.name, a.country  table  left join table b on a.id = b.id , a.name not null

base on following 2 test result

select a.id, a.name,a.country table left join table b on a.id = b.id a.name not null

is faster (237 vs 460). far know, standard.

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And