Oracle queries the table's primary key and foreign key

Summary of some SQL statements used in Oracle to query Table Primary keys and Foreign keys (in oracle): 1. query all indexes of a table (including index names, types, and columns) select t. *, I. index_type from user_ind_columns t, user_indexes I where t. index_name = I. index_name and t. table_name = I. table_name and t. table_name = the table to be queried 2. query the table's primary key (including the name and column composition) select cu. * from user_cons_columns cu, user_constraints au where cu. constraint_name = au. constraint_name and au. constraint_type = 'p' and au. table_name = table to be queried 3. uniqueness constraints for the query table (including names and columns) select column_name from user_cons_columns cu, user_constraints au where cu. constraint_name = au. constraint_name and au. constraint_type = 'U' and au. table_name = table to be queried 4. Search for the table's foreign key (including name, reference table name and corresponding key name, which is divided into multiple steps for query)) select * from user_constraints c where c. constraint_type = 'r' and c. table_name = Name of the column with foreign key constraints for the table to be queried B) select * from user_cons_columns cl where cl. constraint_name = Name of the column where the referenced table key is queried by the foreign key name c) select * from user_cons_columns cl where cl. constraint_name = foreign key reference table key name 5. query all columns of the table and their attributes select t. *, c. COMMENTS from user_tab_columns t, user_col_comments c where t. table_name = c. table_name and t. column_name = c. column_name and t. table_name = table to be queried