Html 如何将SQLCOMMAND转换为INT
我有以下代码,其中表名为student,列名为Html 如何将SQLCOMMAND转换为INT,html,asp.net,sql,vb.net,Html,Asp.net,Sql,Vb.net,我有以下代码,其中表名为student,列名为sem\u of\u study来自INT Dim userquery As String = "select sem_of_study from student where username='" + Session("user") + "'" Dim usercom As New SqlCommand(userquery, conn) Dim a = usercom.ExecuteReader 我想知道是否可以将SQL命令转换为整数,以便在if
sem\u of\u study
来自INT
Dim userquery As String = "select sem_of_study from student where username='" + Session("user") + "'"
Dim usercom As New SqlCommand(userquery, conn)
Dim a = usercom.ExecuteReader
我想知道是否可以将SQL命令转换为整数,以便在if
语句中使用它
所以变量a会
if a=1 then
else if a=2 then
除了应该使用
参数化查询
(这样搜索--大量示例)之外,还需要在数据读取器
行中执行类似的读取操作:
Dim a as Integer
Dim myReader As SqlDataReader = usercom.ExecuteReader()
If myReader.HasRows Then
myReader.Read()
a = myReader.GetInt32(0)
End If
对于参数:
Dim userquery As String = "select sem_of_study from student where username=@username"
Dim usercom as SqlCommand = new SqlCommand()
usercom.Connection = conn
usercom.CommandType = CommandType.Text
usercom.CommendText = userquery
usercom.Parameters.AddWithValue("username", Session("user"))