mysql 获取字段值总和

$sql ="select sum(dingdan_price) from dingdan"

$re = mysql_query($sql)

list($sum)=mysql_fetch_row($re)

mysql_free_result($re)

echo "总和=$sum"

selecti.uid,sum(ifnull(deposit,0)+ifnull(ddeposit,0)+ifnull(money,0))asallmoney

frompw_memberinfoileftjoinpw_membersmonm.uid=i.uidleftjoinpw_memberdatadoni.uid=d.uid

whereifnull(deposit,0)+ifnull(ddeposit,0)+ifnull(money,0)>2000

假如产品表为 tb ，表中有产品编号字段， 销售表为 tb2有销售数量字段，他们通过产品id关联

如果是求所有销售数量的总和

select tb.产品编号，svm(销售数量) as 总销售数量

from the inner join tb2 on tb.产品id=tb2.产品id

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