主题：[讨论] 如何判断外部数据的列类型？

老大的方法:

Dim cnn As new Data.OleDB.OleDbConnection(connections("Sale").ConnectionString)

Dim ada As New Data.OleDB.OleDbDataAdapter("Select *  From 产品 Where [_indentify] is null",cnn)

Dim dt As New Data.DataTable

ada.FillSchema (dt,System.Data.SchemaType.Source)

For Each dc As data.DataColumn In dt.Columns    

    output.show(dc.ColumnName)

    Output.Show(dc.DataType.name)   '列类型

    output.show(dc.MaxLength)

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