从oracle表中的列中获取最大值 [英] fetching max value from a column in oracle table

问题描述

我的编码是这样的

my coding is like this

dim quer as string
dim a as integer
dim dr as OracleDataReader

query = select max(refno)+1 from porder;
orc.open()
cmd = New OracleCommand(query1, orc)
dr = cmd.ExecuteReader()
a = dr.read()

每次显示零(0)

请先提供帮助，并先谢谢您.

each time it is showing the zero(0)

please help and thanks in advance

推荐答案

尝试一下:

替换此:

try this :

replace this:

query = select max(refno)+1 from porder;
orc.open()
cmd = New OracleCommand(query1, orc)

具有:

with:

query = select max(refno)+1 from porder;
orc.open()
cmd = New OracleCommand(query, orc)

当您传递不正确的查询时.

希望对您有所帮助:)

as you are passing the incorrect query.

hope it helps :)

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