-- SQL DML: SCHEMA C##ART
SET search_path TO art;

BEGIN;
-- 20 Queries
-- Q1: Select all columns and all rows from one table
SELECT * FROM USERROLE;

-- Q2: Select five columns and all rows from one table
SELECT CONTACT_ID, FIRST_NAME, LAST_NAME, PHONE_NO, EMAIL FROM CONTACT;

-- Q3: Select all columns from all rows from one view
SELECT * FROM VIEW_AVAILABLE_INVENTORY;

-- Q4: Using a join on 2 tables, select all columns and all rows from the tables without the use of a Cartesian product
SELECT * FROM CONTACT ct
JOIN ADDRESS ad ON ad.FK_CONTACT_ID=ct.CONTACT_ID;

-- Q5: 5: Select and order data retrieved from one table
SELECT * FROM ZIP ORDER BY 1;

-- Q6: Using a join on 3 tables, select 5 columns from the 3 tables. Use syntax that would limit the output to 10 rows
SELECT iv.SKU, iv.PRODUCT_NAME,iv.BASE_PRICE,iv.LEAD_TIME_DAYS, iv.QUANTITY_AVAILABLE,
 au.AUTHORIZATION_STATUS, au.EXPIRATION_DATE, au.AUTHORIZATION_DATE, c.*, au.FK_DOCUMENT_ID
FROM INVENTORY iv
JOIN authorize au ON au.AUTHORIZATION_ID = iv.FK_AUTHORIZATION_ID
JOIN CONTACT c ON c.CONTACT_ID= iv.FK_CONTACT_ID
FETCH FIRST 10 ROWS ONLY;

--Q7: Select distinct rows using joins on 3 tables
SELECT DISTINCT iv.SKU, iv.PRODUCT_NAME,iv.BASE_PRICE,iv.LEAD_TIME_DAYS, iv.QUANTITY_AVAILABLE,
 au.AUTHORIZATION_STATUS, au.EXPIRATION_DATE, au.AUTHORIZATION_DATE, au.FK_CONTACT_ID, au.FK_DOCUMENT_ID,
 oi.ORDER_ITEM_ID, oi.QUANTITY, oi.UNIT_PRICE, oi.TRANSACTION_ID, oi.LINE_TOTAL
FROM INVENTORY iv
JOIN AUTHORIZE au ON au.AUTHORIZATION_ID = iv.FK_AUTHORIZATION_ID
JOIN ORDER_ITEMS oi ON oi.FK_INVENTORY_ID = iv.INVENTORY_ID;

-- Q8: Use GROUP BY and HAVING in a select statement using one or more tables
SELECT iv.SKU
FROM INVENTORY iv
JOIN AUTHORIZE au ON au.AUTHORIZATION_ID = iv.FK_AUTHORIZATION_ID
JOIN ORDER_ITEMS oi ON oi.FK_INVENTORY_ID = iv.INVENTORY_ID
GROUP BY iv.SKU, iv.QUANTITY_AVAILABLE HAVING iv.QUANTITY_AVAILABLE > 0;

-- Q9: Use IN clause to select data from one or more tables
SELECT * FROM PROFILE pf JOIN USERROLE ur ON pf.PROFILE_ID = ur.FK_PROFILE_ID;

-- Q10: Select length of one column from one table (use LENGTH function)
SELECT LENGTH(ROLENAME) FROM USERROLE;

-- Q11: Delete one record from one table. ROLLBACK afterwards so that the data will not be physically removed.
SAVEPOINT sp1;

SELECT * FROM PROFILE pf JOIN USERROLE ur ON pf.PROFILE_ID = ur.FK_PROFILE_ID;
DELETE FROM USERROLE WHERE FK_PROFILE_ID=3;
SELECT * FROM PROFILE pf JOIN USERROLE ur ON pf.PROFILE_ID = ur.FK_PROFILE_ID; 

ROLLBACK TO SAVEPOINT sp1;

-- Q12: Update one record from one table. demonstrate table contents before and after the UPDATE.
SELECT * FROM PROFILE WHERE PROFILE_ID=3;
UPDATE PROFILE SET ACTIVE = FALSE WHERE PROFILE_ID=3;
SELECT * FROM PROFILE WHERE PROFILE_ID=3;

ROLLBACK TO SAVEPOINT sp1;
COMMIT;

-- Q13: Plans show
SELECT * FROM PLAN pl
LEFT OUTER JOIN DOCUMENT doc ON pl.FK_DOCUMENT_ID = doc.DOCUMENT_ID;

-- Q14: show authorized suppliers whose expiration date is greater than 30 days from now.
SELECT * FROM VIEW_SUPPLIER vsu
LEFT OUTER JOIN AUTHORIZE aut ON aut.FK_CONTACT_ID = vsu.FK_CONTACT_ID
WHERE aut.AUTHORIZATION_STATUS='approved' AND aut.EXPIRATION_DATE > CURRENT_TIMESTAMP + INTERVAL '30 days';

-- Q15:
SELECT ur.ROLENAME, ct.FIRST_NAME, ct.LAST_NAME, pl.DESCRIPTION FROM SUBSCRIPTION srp
LEFT OUTER JOIN CONTACT ct ON srp.FK_CONTACT_ID = ct.CONTACT_ID
LEFT OUTER JOIN PROFILE pf ON pf.FK_CONTACT_ID = ct.CONTACT_ID
LEFT OUTER JOIN USERROLE ur ON ur.FK_PROFILE_ID = pf.PROFILE_ID
LEFT OUTER JOIN PLAN pl ON srp.FK_PLAN_ID = pl.PLAN_ID;

-- Q16:
SELECT ct.FIRST_NAME, ct.LAST_NAME, adr.STREET, z.CITY, z.STATE, z.ZIP
FROM ADDRESS adr
LEFT OUTER JOIN CONTACT ct ON adr.FK_CONTACT_ID = ct.CONTACT_ID
LEFT OUTER JOIN ZIP z ON adr.ZIP = z.ZIP;

-- Q17:
SELECT COALESCE(vws.ROLENAME, vwsp.ROLENAME, vwc.ROLENAME, vwsys.ROLENAME) AS ROLENAME,
       COALESCE(vws.ACTIVE, vwsp.ACTIVE, vwc.ACTIVE, vwsys.ACTIVE) AS ACTIVE,
       ct.FIRST_NAME, ct.LAST_NAME, adr.STREET, z.CITY, z.STATE, z.ZIP
FROM ADDRESS adr
LEFT OUTER JOIN CONTACT ct ON adr.FK_CONTACT_ID = ct.CONTACT_ID
LEFT OUTER JOIN ZIP z ON adr.ZIP = z.ZIP
LEFT OUTER JOIN VIEW_STAFF vws ON vws.FK_CONTACT_ID = ct.CONTACT_ID
LEFT OUTER JOIN VIEW_SUPPLIER vwsp ON vwsp.FK_CONTACT_ID = ct.CONTACT_ID
LEFT OUTER JOIN VIEW_CUSTOMER vwc ON vwc.FK_CONTACT_ID = ct.CONTACT_ID
LEFT OUTER JOIN VIEW_SYSTEMROLE vwsys ON vwsys.FK_CONTACT_ID = ct.CONTACT_ID;

-- Q18: Verify rows in tables
SELECT 'CONTACT'        AS TABLE_NAME, COUNT(*) AS ROW_COUNT FROM CONTACT        UNION ALL
SELECT 'ZIP',                          COUNT(*)              FROM ZIP            UNION ALL
SELECT 'ADDRESS',                      COUNT(*)              FROM ADDRESS        UNION ALL
SELECT 'PROFILE',                      COUNT(*)              FROM PROFILE        UNION ALL
SELECT 'USERROLE',                     COUNT(*)              FROM USERROLE       UNION ALL
SELECT 'STAFF',                        COUNT(*)              FROM STAFF          UNION ALL
SELECT 'DOCUMENT',                     COUNT(*)              FROM DOCUMENT       UNION ALL
SELECT 'AUTHORIZE',                    COUNT(*)              FROM AUTHORIZE      UNION ALL
SELECT 'PLAN',                         COUNT(*)              FROM PLAN           UNION ALL
SELECT 'INVENTORY',                    COUNT(*)              FROM INVENTORY      UNION ALL
SELECT 'EXHIBIT',                      COUNT(*)              FROM EXHIBIT        UNION ALL
SELECT 'ORDER_ITEMS',                  COUNT(*)              FROM ORDER_ITEMS    UNION ALL
SELECT 'INVOICE',                      COUNT(*)              FROM INVOICE        UNION ALL
SELECT 'SUBSCRIPTION',                 COUNT(*)              FROM SUBSCRIPTION   UNION ALL
SELECT 'TASK_HISTORY',                 COUNT(*)              FROM TASK_HISTORY
ORDER BY TABLE_NAME;

-- Q19: rough check uniqueness: across tables columns
-- Q19: Unique index column counts per table
--      Oracle: user_indexes + user_ind_columns
--      PG equivalent: pg_indexes (basic) or pg_index + pg_class + pg_attribute
SELECT
    t.relname                          AS table_name,
    COUNT(DISTINCT i.indexrelid)       AS unique_index_count,
    COUNT(a.attname)                   AS unique_column_count
FROM pg_index     i
JOIN pg_class     t  ON t.oid = i.indrelid
JOIN pg_class     ix ON ix.oid = i.indexrelid
JOIN pg_attribute a  ON a.attrelid = t.oid
                     AND a.attnum  = ANY(i.indkey)
WHERE i.indisunique     = TRUE
  AND t.relnamespace    = (SELECT oid FROM pg_namespace WHERE nspname = current_schema())
GROUP BY t.relname
ORDER BY t.relname;

-- Q20: Likely weak entity tables — tables where a PK column is also an FK column
--      Oracle: all_cons_columns + all_constraints filtered to USER
--      PG equivalent: information_schema tables
SELECT tc.table_name
FROM information_schema.table_constraints  tc
JOIN information_schema.key_column_usage   kcu_pk
       ON  kcu_pk.constraint_name = tc.constraint_name
       AND kcu_pk.table_schema    = tc.table_schema
JOIN information_schema.key_column_usage   kcu_fk
       ON  kcu_fk.table_name  = tc.table_name
       AND kcu_fk.column_name = kcu_pk.column_name
       AND kcu_fk.table_schema= tc.table_schema
JOIN information_schema.table_constraints  fkc
       ON  fkc.constraint_name = kcu_fk.constraint_name
       AND fkc.table_schema    = kcu_fk.table_schema
WHERE tc.constraint_type  = 'PRIMARY KEY'
  AND fkc.constraint_type = 'FOREIGN KEY'
  AND tc.table_schema     = current_schema()
GROUP BY tc.table_name
ORDER BY tc.table_name;

COMMIT;