select left(sub.subjectdesignameno,2) as subjectdesignameno from acc_vouchdetail vd
left outer join acc_subjectdesigname sub on vd.subjectdesigname_id = sub.subjectdesigname_id 這樣的結果是
subjectnameno
4但是我加上這樣的條件,居然連一條記錄都不顯示了,為什么
where subjectdesignameno = '4'
left outer join acc_subjectdesigname sub on vd.subjectdesigname_id = sub.subjectdesigname_id 這樣的結果是
subjectnameno
4但是我加上這樣的條件,居然連一條記錄都不顯示了,為什么
where subjectdesignameno = '4'
那你在WHERE时.是看不到这个SELECT..所以你可以尝试 WHERE left(sub.subjectdesignameno,2)='4'
select left(sub.subjectdesignameno,2) as subjectdesignameno
from acc_vouchdetail vd
left outer join acc_subjectdesigname sub on vd.subjectdesigname_id = sub.subjectdesigname_id
where ltrim(left(sub.subjectdesignameno,2))='4'
不等于
sub.subjectdesignameno = "4"原因楼上说了.
功能得到字符串左部指定个数的字符。
语法Left ( string, n )
select
left(sub.subjectdesignameno,2) as subjectdesignameno
from
acc_vouchdetail vd
left outer join
acc_subjectdesigname sub
on
vd.subjectdesigname_id = sub.subjectdesigname_id
having subjectdesignameno='4'用having 就可以了