private IEnumerable <DataColumn> GetColumns(ClickHouseDataReader reader)
{
for (int i = 0; i < reader.FieldCount; i++)
{
var columnType = reader.GetFieldType(i);
yield return(new DataColumn(reader.GetName(i), columnType));
}
}
private static object[] DescribeColumn(this ClickHouseDataReader reader, int ordinal)
{
var chType = reader.GetClickHouseType(ordinal);
var result = new object[Columns.Length];
result[0] = reader.GetName(ordinal); // ColumnName
result[1] = ordinal; // ColumnOrdinal
result[2] = null; // ColumnSize
result[3] = null; // NumericPrecision
result[4] = null; // NumericScale
result[5] = chType.FrameworkType; // DataType
result[6] = chType.ToString(); // ProviderType
result[7] = chType.TypeCode == ClickHouseTypeCode.String; // IsLong
result[8] = chType.TypeCode == ClickHouseTypeCode.Nullable; // AllowDBNull
result[9] = true; // IsReadOnly
result[10] = false; // IsRowVersion
result[11] = false; // IsUnique
result[12] = false; // IsKey
result[13] = false; // IsAutoIncrement
result[14] = null; // BaseCatalogName
result[15] = null; // BaseSchemaName
result[16] = null; // BaseTableName
result[17] = reader.GetName(ordinal); // BaseColumnName
result[18] = null; // AutoIncrementSeed
result[19] = null; // AutoIncrementStep
result[20] = null; // DefaultValue
result[21] = null; // Expression
result[22] = MappingType.Element; // ColumnMapping
result[23] = null; // BaseTableNamespace
result[24] = null; // BaseColumnNamespace
if (chType is DecimalType dt)
{
result[2] = dt.Size;
result[3] = dt.Precision;
result[4] = dt.Scale;
}
return(result);
}