TcaplusDB Client - desc命令
TcaplusDB Client的使用方法参见文档。
1. 功能说明
查看表的字段信息。
嵌套类型字段只能看到其字段类型为嵌套类型，无法查看嵌套结构体的信息。
2. 启始版本
3.40.0
3. 命令语法
desc [table]/[table.field] [using tdr];
参数说明：
| 参数 | PB表 | TDR表 |
|---|---|---|
| table | 表格的名字 | 表格的名字 |
| table.field | 不支持 | 显示嵌套字段的结构，必须配合using tdr使用 |
| using tdr | 不支持 | 从TDR文件中读取表结构 如果需要使用该参数，则在启动TcaplusDB Client时，就要通过启动参数指定与目标表对应的TDR文件 |
4. 命令示例
表定义详见示例表定义。
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 |- |三层嵌套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. 常见错误
参考常见错误文档。