createtable t1 ( id number, col1 varchar2(100), col2 varchar2(100), col3 generatedalwaysas (id+100) virtual ) partition by range (id) ( partition p1 values less than (200), partition p2 values less than (400) );
xb@PDB12C> @desc t1 NameNull? Type ------------------------------- -------- ---------------------------- 1 ID NUMBER >>>>====已经看不到col1和col2两个字段 2 COL3 NUMBER
col column_namefor a40 col data_type for a20 col data_length for999999999999 col data_default for a20 col virtual_column for a20 SELECTcolumn_name, data_type, data_length, data_default, virtual_column FROM user_tab_cols WHEREtable_name = 'T1';
COLUMN_NAME DATA_TYPE DATA_LENGTH DATA_DEFAULT VIRTUAL_COLUMN ---------------------------------------- -------------------- ------------- -------------------- -------------------- ID NUMBER 22NO SYS_C00002_19031410:18:00$ VARCHAR2 100NO COL2 VARCHAR2 100NO COL3 NUMBER 22 "ID"+100 YES
createtable t2 for exchange withtable t1; createindex idx_t2 on t2(id);
col column_namefor a40 col data_type for a20 col data_length for999999999999 col data_default for a20 col virtual_column for a20 SELECTcolumn_name, data_type, data_length, data_default, virtual_column FROM user_tab_cols WHEREtable_name = 'T2';
COLUMN_NAME DATA_TYPE DATA_LENGTH DATA_DEFAULT VIRTUAL_COLUMN ---------------------------------------- -------------------- ------------- -------------------- -------------------- COL2 VARCHAR2 100NO SYS_C00002_19031410:18:00$ VARCHAR2 100NO ID NUMBER 22NO COL3 NUMBER 22 "ID"+100 YES