VBA执行存储过程

Question

我无法执行存储过程。我有这个代码

Set conn = New ADODB.Connection
    conn.Open connectionString
    Set cmd = New ADODB.Command
    With cmd
        .ActiveConnection = conn
        .CommandText = "schemaname.usp_proc"
        .CommandType = adCmdStoredProc
        .CommandTimeout = 300
        .Parameters.Append .CreateParameter("@user", adVarWChar, adParamInput, , user)
        .Execute
    End With

用户参数为NVARCHAR(255)

我遇到错误Type Mismatch

这是怎么了？