TcaplusDB Client - Desc Command
For TcaplusDB Client Instructions, see Document.
1. Function Descriptions
View the field description of a table.
If it is a nested type field, its field type can only be viewed as a nested type, and the description of the nested structure cannot be viewed.
2. Initial Version
3.40.0
3. Command Syntax
desc [table]/[table.field] [using tdr];
Parameter description:
| Parameter | PB Table | TDR Table |
|---|---|---|
| table | Table name | Table name |
| table.field | Do not support | It can be used to display the structure of nested fields and must be used with using tdr |
| using tdr | Do not support | Read the table structure from the TDR file. If you need to use this parameter, you should specify the TDR file corresponding to the target table through the startup parameter when starting the TcaplusDB Client |
4. Command Example
See Table Definition Example for table definition.
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-layer nested 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)
5. Common Errors
Refer to Common Errors.