Bug #88509 ExecuteScalar, ExecuteNonQuery and ExecuteReader suspended

• Submitted: 16 Nov 2017 1:53
• Modified: 26 Jul 21:59
• Reporter: JACK ZOU
• Status: Can't repeat
• Category: Connector / NET
• Severity: S4 (Feature request)
• Version: 6.10.4
• OS: Windows
• CPU Architecture: Any
• Tags: ExecuteNonQuery, ExecuteReader, ExecuteScalar

[16 Nov 2017 1:53] JACK ZOU

Description:
Execute a query: select left(rand(),3), count(*) from information_schema.tables group by 1
can got error message: Duplicate entry '0.5' for key '<group_key>'

but execute batch query:  select left(rand(),3), count(*) from information_schema.tables group by 1; select left(rand(),3), count(*) from information_schema.tables group by 1
Execute method suspended and session in MySQL is sleep

How to repeat:
Imports MySql.Data.MySqlClient
Module Module1

    Sub Main()
        Dim connstr = New MySqlConnectionStringBuilder With {
            .Server = "localhost", .Port = "3306", .Database = "mysql",
            .UserID = "dba_jack", .Password = "jack.1234",
            .AllowBatch = True}.ConnectionString
        Using conn As New MySqlConnection(connstr)
            conn.Open()
            Console.WriteLine(" *** Test 2 =================================")
            Dim sql = "select left(rand(),3), count(*) from information_schema.tables group by 1"
            Console.WriteLine(sql)
            Query(conn, sql)            ' Sucess got error

            Console.WriteLine(" *** Test 2 =================================")
            sql &= ";" & sql
            Console.WriteLine(sql)
            Query(conn, sql)            ' Suspended on ExecuteScalar, ExecuteNonQuery and ExecuteReader
            conn.Close()
        End Using
    End Sub

    Sub Query(conn As MySqlConnection, sql As String)
        Try
            Using cmd As New MySqlCommand(sql, conn)
                ' Console.WriteLine(cmd.ExecuteScalar ())
                ' Console.WriteLine(cmd.ExecuteNonQuery())
                Using reader = cmd.ExecuteReader
                    If reader.IsClosed = False Then
                        While reader.Read()
                            Console.WriteLine(reader(0))
                        End While
                        reader.Close()
                    End If
                End Using
            End Using
        Catch ex As Exception
            Console.WriteLine(ex.Message)
        End Try
    End Sub
End Module