code: func fieldTypeFromPBColumn(col *tipb.ColumnInfo) *types.FieldType {
  	return &types.FieldType{
  		Tp:      byte(col.GetTp()),
  		Flag:    uint(col.Flag),
  		Flen:    int(col.GetColumnLen()),
  		Decimal: int(col.GetDecimal()),
  		Elems:   col.Elems,
  		Collate: mysql.Collations[uint8(col.GetCollation())],
  	}
  }
docs: // fieldTypeFromPBColumn creates a types.FieldType from tipb.ColumnInfo.