how to select data from two tables in sql without join code example

Example 1: join multiple tables sql

SELECT TableA.*, TableB.*, TableC.*, TableD.*
FROM TableA
    JOIN TableB
        ON TableB.aID = TableA.aID
    JOIN TableC
        ON TableC.cID = TableB.cID
    JOIN TableD
        ON TableD.dID = TableA.dID
WHERE DATE(TableC.date)=date(now())

Example 2: sql select from multiple tables without join

-- UNION: distinct values (slower)
SELECT emp_name AS name from employees
UNION       
SELECT cust_name AS name from customers;

-- UNION ALL: keeps duplicates (faster)
SELECT emp_name AS name from employees
UNION ALL      
SELECT cust_name AS name from customers;

Example 3: sql combine results from two tables

SELECT *
  FROM tutorial.crunchbase_investments_part1

 UNION

 SELECT *
   FROM tutorial.crunchbase_investments_part2