select * from tab_a inner join tab_b on tab_a.col1 = tab_b.col1 inner join tab_c on tab_b.col1 = taselect * from tab_a inner join tab_b on tab_a.col1 = tab_b.col1inner join tab_c on tab_b.col1 = tab_c.col1 and tab_b.col2 = tab_c.col2;其中的co|1、

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select * from tab_a inner join tab_b on tab_a.col1 = tab_b.col1 inner join tab_c on tab_b.col1 = taselect * from tab_a inner join tab_b on tab_a.col1 = tab_b.col1inner join tab_c on tab_b.col1 = tab_c.col1 and tab_b.col2 = tab_c.col2;其中的co|1、

select * from tab_a inner join tab_b on tab_a.col1 = tab_b.col1 inner join tab_c on tab_b.col1 = taselect * from tab_a inner join tab_b on tab_a.col1 = tab_b.col1inner join tab_c on tab_b.col1 = tab_c.col1 and tab_b.col2 = tab_c.col2;其中的co|1、
select * from tab_a inner join tab_b on tab_a.col1 = tab_b.col1 inner join tab_c on tab_b.col1 = ta
select * from
tab_a inner join tab_b on
tab_a.col1 = tab_b.col1
inner join tab_c on
tab_b.col1 = tab_c.col1
and tab_b.col2 = tab_c.col2;
其中的co|1、co|2是指什么,tab_a 、 tab_b 、tab_c是表名对吧,on tab_b.col1 = tab_c.col1 and tab_b.col2 = tab_c.col2;是指什么

select * from tab_a inner join tab_b on tab_a.col1 = tab_b.col1 inner join tab_c on tab_b.col1 = taselect * from tab_a inner join tab_b on tab_a.col1 = tab_b.col1inner join tab_c on tab_b.col1 = tab_c.col1 and tab_b.col2 = tab_c.col2;其中的co|1、
co|1、co|2 表的列1列2的简写 ; on tab_b.col1 = tab_c.col1 and tab_b.col2 = tab_c.col2是指join的字段