1，虽然同样是实现了IDataReader接口，但是 对于
MySql.Data.MySqlClient.MySqlDataReader 和 System.Data.SqlClient.SqlDataReader
来说GetSchemaTable 方法的返回结果是不同的
以下是返回的datatable的结构
| mysql | sqlserver |
| AllowDBNull | AllowDBNull |
| BaseCatalogName | BaseCatalogName |
| BaseColumnName | BaseColumnName |
| BaseSchemaName | BaseSchemaName |
| BaseTableName | BaseServerName |
| ColumnName | BaseTableName |
| ColumnOrdinal | ColumnName |
| ColumnSize | ColumnOrdinal |
| DataType | ColumnSize |
| IsAliased | DataType |
| IsAutoIncrement | DataTypeName |
| IsExpression | IsAliased |
| IsHidden | IsAutoIncrement |
| IsIdentity | IsColumnSet |
| IsKey | IsExpression |
| IsLong | IsHidden |
| IsReadOnly | IsIdentity |
| IsRowVersion | IsKey |
| IsUnique | IsLong |
| NumericPrecision | IsReadOnly |
| NumericScale | IsRowVersion |
| ProviderType | IsUnique |
| NonVersionedProviderType | |
| NumericPrecision | |
| NumericScale | |
| ProviderSpecificDataType | |
| ProviderType | |
| UdtAssemblyQualifiedName | |
| XmlSchemaCollectionDatabase | |
| XmlSchemaCollectionName | |
| XmlSchemaCollectionOwningSchema |