Last updated: 2020-12-25 16:40:13

    Overview

    This command is used to view the table definition information. For a nested field, you can only see that its attribute is nested type, but you cannot view the nested structure definition.

    Syntax

    desc [table]/[table.field] [using tdr];

    Parameters

    Parameter Protobuf TDR
    table Table name Table name
    table.field Not supported To show the structure of a nested field, using tdr needs to be used along with this parameter.
    using tdr Not supported This parameter is used to query the table structure from a TDR file which must be provided when the client is launched.

    Errors

    For more information, please see Error Codes.

    Sample

    tcaplus> desc table_list;
    
    Table Structure From: Tcaplus System
    TableName: table_list
    TableType: LIST, IdlType: TDRXML
    SvrTdrCurrentVersion: 5
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |Field                |Type                |Key     |Index|Size  |Version|DefaultValue|Count|Select               |Desc          |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |uin                  |unsigned long long  |PRI,SPLT|-    |8     |1      |-           |1    |-                    |QQ            |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |name                 |string              |PRI     |-    |640   |1      |-           |1    |-                    |Name          |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |key1                 |unsigned char       |PRI     |-    |1     |1      |-           |1    |-                    |key4          |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |level                |int                 |-       |-    |4     |1      |1           |1    |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |count                |unsigned char       |-       |-    |1     |1      |0           |1    |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |array_count          |unsigned int        |-       |-    |4     |1      |1           |1    |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |items                |unsigned long long[]|-       |-    |8     |1      |-           |10   |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |c_int8               |char                |-       |-    |1     |1      |-1          |1    |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |c_uint8              |unsigned char       |-       |-    |1     |1      |2           |1    |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |c_int16              |short               |-       |-    |2     |1      |-3          |1    |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |c_uint16             |unsigned short      |-       |-    |2     |1      |4           |1    |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |c_int32              |int                 |-       |-    |4     |1      |-5          |1    |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |c_uint32             |unsigned int        |-       |-    |4     |1      |6           |1    |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |c_int64              |long long           |-       |-    |8     |1      |-7          |1    |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |c_uint64             |unsigned long long  |-       |-    |8     |1      |-           |1    |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |c_float              |float               |-       |-    |4     |2      |1.234568    |1    |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |c_double             |double              |-       |-    |8     |3      |9.876543    |1    |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |c_string             |string              |-       |-    |200   |3      |-           |1    |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |c_string_128K        |string              |-       |-    |131072|1      |123456789   |1    |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |c_string_256K        |string              |-       |-    |262144|1      |123456789   |1    |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |c_binary             |char[]              |-       |-    |1     |1      |-           |10   |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |binary               |char                |-       |-    |1     |5      |-           |1    |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |selector             |short               |-       |-    |2     |1      |-           |1    |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |single_struct        |struct_type         |-       |-    |119   |1      |-           |1    |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |simple_struct        |simple_struct       |-       |-    |30    |4      |-           |1    |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |single_union_selector|char                |-       |-    |1     |1      |0           |1    |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |single_union         |union_type          |-       |-    |64    |1      |-           |1    |single_union_selector|-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |array                |TableInfo[]         |-       |-    |125   |1      |-           |3    |-                    |three lyaer struct|
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |c_union              |union_type          |-       |-    |64    |1      |-           |1    |selector             |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |union_array          |union_type[]        |-       |-    |64    |1      |-           |3    |selector             |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |c_struct             |struct_type         |-       |-    |119   |1      |-           |1    |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    |struct_array         |struct_type[]       |-       |-    |119   |1      |-           |3    |-                    |-             |
    +---------------------+--------------------+--------+-----+------+-------+------------+-----+---------------------+--------------+
    
    32 rows in set (36252 us)
    
    tcaplus> desc table_list.single_struct using tdr;
    
    Table Structure From: Local tdr file(/mnt/e/tdr/2.3.table_list.tdr)
    table_list.single_struct
    |---single_struct(struct)
    |   |---x(int)
    |   |---y(int)
    |   |---score(double)
    |   |---rank(uchar)
    |   |---title(string)
    |   |---level2_struct(struct)
    |   |   |---uin(int)
    |   |   |---name(string)