我是Visual Studio中Oracle的新手,
我使用Oracle.ManagedDataAccess作为参考,这种情况是,每当我试图从Oracle查询中的算术中检索十进制值时,它总是返回null
例如
SELECT 26/3 FROM DUAL
<----这段代码在我的visual studio中返回null,但在TOAD中有一个值
我做错了吗?
这是我检索值的代码
List<object[]> result = new List<object[]>();
OracleDataReader data;
string constr = ConfigurationManager.ConnectionStrings["OraConnection"].ConnectionString;
using (OracleConnection con = new OracleConnection(constr))
{
string query = QueryString;
using (OracleCommand cmd = new OracleCommand(query))
{
cmd.Connection = con;
con.Open();
data = cmd.ExecuteReader();
try
{
if (data.HasRows)
{
while (data.Read())
{
object[] itemData = new object[data.FieldCount];
//Dictionary<string, string> itemData = new Dictionary<string, string>();
for (int i = 0; i < data.FieldCount; i++)
{
Type type = data.GetValue(i).GetType();
if (typeof(string) == type)
{
itemData[i] = data.GetString(i);
}
if (typeof(DateTime) == type)
{
itemData[i] = data.GetDateTime(i);
}
if (typeof(int) == type)
{
itemData[i] = data.GetInt32(i);
}
if (typeof(decimal) == type)
{
itemData[i] = data.GetDecimal(i);
}
if (typeof(bool) == type)
{
itemData[i] = data.GetBoolean(i);
}
if (typeof(TimeSpan) == type)
{
itemData[i] = data.GetTimeSpan(i);
}
if (typeof(Single) == type)
{
itemData[i] = Convert.ToDecimal(data.GetOracleDecimal(i).ToString());
}
}
result.Add(itemData);
}
}
else
{
Console.WriteLine("Rows not found.");
}
}
finally
{
data.Close();
}
con.Close();
}
}
return result;
更新:仅对于具有十进制值的除法,它就变为null。加法、减法、乘法没有问题
您的数据类型似乎与任何if
表达式都不匹配。由于没有默认分支,itemData[i]
保持为空。我建议用以下方法来找出差距:
for (int i = 0; i < data.FieldCount; i++)
{
Type type = data.GetValue(i).GetType();
switch(type)
{
case typeof(string):
itemData[i] = data.GetString(i);
break;
case typeof(DateTime):
itemData[i] = data.GetDateTime(i);
break;
case typeof(int):
itemData[i] = data.GetInt32(i);
break;
case typeof(decimal):
itemData[i] = data.GetDecimal(i);
break;
case typeof(bool):
itemData[i] = data.GetBoolean(i);
break;
case typeof(TimeSpan):
itemData[i] = data.GetTimeSpan(i);
break;
case typeof(Single):
itemData[i] = Convert.ToDecimal(data.GetOracleDecimal(i).ToString());
break;
default:
MessageBox.Show("Unknown type " + type.Name);
break;
}
}
因此,我收到了编辑oracle查询的建议
From(例如(SELECT 26/7 FROM DUAL
toSELECT TO_CHAR(26/7) FROM DUAL
是的,它有效
但是,我仍然不知道为什么