Question

我要从数据库中提取日期“ ddMMyyyy”，然后将其转换为MM-dd-yyyy”，然后再显示输出。由于某些原因，有些日期仅包含7位数字，默认情况下必须为8位数字。

当系统发现日期中的数字少于8个字符时，它会引发转换日期的错误，作为一种选择，我想在显示输出的当天添加0。例如08-12-1983，默认情况下来自数据库8-12-1983

我想在显示输出的那一天加0。

我使用vb.net和sql命令。

这是我的代码。

Public BGC1, BGC2, BGC3, BGC4 As String
Public str As String

 Public Sub GetBGC()
        Try
            myConnection.Open()
            'Main.PresStartResults.Text = "Prestart Checks : "
            'Main.BGCName.Text = "Employee Name "
            'Main.BGCDOB.Text = "DOB"
            'Dim str As String
            str = "SELECT * FROM tblEmp WHERE (EmpID = '" & ADS.UserEmpID & "')"
            Dim cmd As OleDbCommand = New OleDbCommand(str, myConnection)
            dr = cmd.ExecuteReader
            While dr.Read()
                Dim stringinp = dr("DOB").ToString
                Dim DateTime1 = DateTime.ParseExact(stringinp, "ddMMyyyy", System.Globalization.CultureInfo.InvariantCulture)
                Dim outp = DateTime1.ToString("MM-dd-yyyy")
                BGC3 = outp


            End While


        Catch ex As Exception

            MsgBox("Unable to Connect to BGC DB. You may not have access or DB not available." & ex.ToString)
        End Try

myConnection.Close()

Answer 1

Imports System
Imports System.Globalization

Public Module Module1

    Public Sub Main()

        Dim dateValue as DateTime
        Dim stringinp as String
        stringinp = "8-12-1983"
        Dim formats = New String(){"dd-MM-yyyy", "d-MM-yyyy", "MM-dd-yyyy"}

        For Each format as String in formats
            If DateTime.TryParseExact(stringinp, formats, System.Globalization.CultureInfo.InvariantCulture, DateTimeStyles.None, dateValue)
                Exit For            
            End If
        Next

        Console.WriteLine(dateValue)

    End Sub
End Module

Answer 2

您可以使用PadLeft方法，如下所示：

Dim stringinp = dr("DOB").ToString().PadLeft(8, "0")

它将在字符串的开头附加零，直到字符串的长度等于8。

Answer 3

尝试

str = "SELECT * FROM tblEmp WHERE (EmpID = '" & ADS.UserEmpID & "')"
            Dim cmd As OleDbCommand = New OleDbCommand(str, myConnection)
            dr = cmd.ExecuteReader
            While dr.Read()
                dim mydate as Date = dr("DOB")
                Dim outp = mydate.tostring("M/dd/yyyy")
                BGC3 = outp


            End While

或

Dim outp = mydate.tostring("MM/dd/yyyy")

如何从转换为MM-DD-yyyy的格式日期开始添加文本“ 0”

3 个答案: