无法将 MySQL 日期/时间值转换为 System.DateTime

Question

I get this error:

Unable to convert MySQL date/time value to System.DateTime

while I am trying to fetch the data from a MySQL database. I have the date datatype in my MySQL database. But while retrieving it into my datatable, it get the error above.

How can I fix this?

Answer 1

您必须将Convert Zero Datetime=True添加到您的连接字符串中，例如：

server=localhost;User Id=root;password=mautauaja;Persist Security Info=True;database=test;Convert Zero Datetime=True

Answer 2

If I google for "Unable to convert MySQL date/time value to System.DateTime" I see numerous references to a problem accessing MySQL from Visual Studio. Is that your context?

One solution suggested is:

This is not a bug but expected behavior. Please check manual under connect options and set "Allow Zero Datetime" to true, as on attached pictures, and the error will go away.

Reference: http://bugs.mysql.com/bug.php?id=26054

Answer 3

我添加了Convert Zero Datetime=True和Allow Zero Datetime=True并且它工作正常

Answer 4

Pull the datetime value down as a string and do a DateTime.ParseExact(value, "ddd MMM dd hh:mm:ss yyyy", culture, styles); You would just need to set the date format up for the date you are returning from the database. Most likely it's yyyy-MM-dd HH:mm:ss . At least is is for me.

Check here more info on the DateTime.ParseExact

Answer 5

I also faced the same problem, and get the columns name and its types. Then cast(col_Name as Char) from table name. From this way i get the problem as '0000-00-00 00:00:00' then I Update as valid date and time the error gets away for my case.

Answer 6

Let MySql convert your unix timestamp to string. Use the mysql function FROM_UNIXTIME( 113283901 )

Answer 7

Rather than changing the connection string, you can use the IsValidDateTime property of the MySqlDateTime object to help you determine if you can cast the object as a DateTime .

I had a scenario where I was trying to load data from an "UpdateTime" column that was only explicitly set when there was an update to the row (as opposed to the InsertedTime which was always set). For this case, I used the MySqlDataReader.GetMySqlDateTime method like so:

using (MySqlDataReader reader = await MySqlHelper.ExecuteReaderAsync(...))
{
    if (await reader.ReadAsync())
    {
        DateTime? updateTime = reader.GetMySqlDateTime("UpdateTime").IsValidDateTime ? (DateTime?)reader["UpdateTime"] : null;
    }
}

Answer 8

在 Stimulsoft 报告中，将此参数添加到连接字符串中（右键单击数据源-> 编辑）

Convert Zero Datetime=True;

Answer 9

You can make the application fully compatible with the date and time that is used by MySql. When the application runs at runtime provide this code. First Go to the Application Events. In the list of tools

1. Go to the project
2. Project Properties
3. Select the Application tab
4. View Application Events

This will open a new file. This file contains code used at the start of the application.

Write this code in that new file:

 Partial Friend Class MyApplication

    Private Sub MyApplication_Startup(ByVal sender As Object, ByVal e As Microsoft.VisualBasic.ApplicationServices.StartupEventArgs) Handles Me.Startup
        My.Application.ChangeCulture("en")
        My.Application.ChangeUICulture("en")
        My.Application.Culture.DateTimeFormat.ShortDatePattern = "yyyy-MM-dd"
        My.Application.Culture.DateTimeFormat.LongDatePattern = "yyyy-MM-dd"
        My.Application.Culture.DateTimeFormat.LongTimePattern = "HH:mm:ss"
        My.Application.Culture.DateTimeFormat.ShortTimePattern = "HH:mm:ss"
    End Sub


End Class

Answer 10

if "allow zero datetime=true" is not working then use the following sollutions:-

Add this to your connection string: "allow zero datetime=no" - that made the type cast work perfectly.

Answer 11

When you're using EF edmx with MySql, please review the Precision attribute in the entitytype.

<EntityType Name="table">
  <Key>
    <PropertyRef Name="Id" />
  </Key>
  <Property Name="Id" Type="int" StoreGeneratedPattern="Identity" Nullable="false" />
  <Property Name="date_field" Type="datetime" Precision="0" Nullable="false" />
</EntityType>

If you made changes in the datetime field, it could be possible you're missing this attribute in the property.