View All Tables, user tables, column names, primary keys, and foreign keys in Oracle

View all tables in Oracle:
Select * From TAB/dba_tables/dba_objects/CAT;
View the table created by the user:
Select table_name from user_tables; // The table of the current user
Select table_name from all_tables; // tables of all users
Select table_name from dba_tables; // includes the system table
Select * From user_indexes // all user table indexes can be queried.
Query all user tables in all_tables
Primary Key name and foreign key in all_constraints
Index in all_indexes
However, the primary key will also become an index, so the primary key will also be in all_indexes.
You can DESC the required fields to view these views. If you log on to the DBA, you can change all to DBA.
1. Search for 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 = table to be queried
2. Search for the table's primary key (including names and columns ):
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. query the uniqueness constraints of a 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 the name, referenced table name, and corresponding key name. The following is a multi-step query ):
Select * From user_constraints c Where C. constraint_type = "R" and C. table_name = table to be queried
Query the names of Columns with foreign key constraints:
Select * From user_cons_columns Cl where Cl. constraint_name = foreign key name
Query the column name of the key of the referenced table:
Select * From user_cons_columns Cl where Cl. constraint_name = foreign key reference table key name
5. query all the columns and their attributes of the table.
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