How to use cross join twice SQL - sql

Question

Table1:
ID
Name
Class
1
Paul
1st
Table2:
ID
Name
Class
Date
Intime
INAM
1
Paul
1st
06-12-2022
8:30AM
P
Table3:
ID
Name
Class
Date
Outtime
OUTPM
1
Paul
1st
06-12-2022
4:30PM
P
Table4:
ID
Name
Class
Date
Intime
Outtime
INAM
OUTPM
ID
Paul
1st
06-12-2022
8:30AM
4:30PM
P
P
I have two tables('Table2','Table3') I'm trying to join these two tables and insert into Table4 using Table1.
I have tried:
INSERT INTO table4
SELECT DISTINCT
COALESCE(tt.ID, t1.ID) AS ID,
COALESCE(tt.Name, t1.Name) AS Name,
COALESCE(tt.Class, t1.Class) AS Class,
tt.Date, tt.Intime, tt.Outtime, tt.INAM, tt.OUTPM
FROM
table1 AS t1
CROSS JOIN
(SELECT * FROM Table4
UNION ALL
SELECT ID, Name, Class, Indate AS Date, Intime, NULL, INAM, NULL
FROM Table2) AS tt
CROSS JOIN
(SELECT * FROM Table4
UNION ALL
SELECT ID, Name, Class, Outdate AS Date, NULL, Outtime, NULL, OUTPM
FROM Table3) AS tt
SELECT * FROM Table4
Please someone help me two join Table2 and Table3 and insert into Table4 using Table1. Thank you...

Answer 1

Try this code
I start by create tables for your testdata
USE [tempdb]
IF OBJECT_ID('table1') IS NOT NULL DROP TABLE table1
CREATE TABLE table1 (ID int, Name varchar(50), Class varchar(20))
INSERT INTO table1 VALUES (1, 'Paul', '1st')
IF OBJECT_ID('table2') IS NOT NULL DROP TABLE table2
CREATE TABLE table2 (ID int, Name varchar(50), Class varchar(20), Date date, Intime time, INAM varchar(20))
INSERT INTO table2 VALUES (1, 'Paul', '1st', '2022-12-06', '8:30AM', 'P')
IF OBJECT_ID('table3') IS NOT NULL DROP TABLE table3
CREATE TABLE table3 (ID int, Name varchar(50), Class varchar(20), Date date, Outtime time, OUTPM varchar(20))
INSERT INTO table3 VALUES (1, 'Paul', '1st', '2022-12-06', '4:30PM', 'P')
IF OBJECT_ID('table4') IS NOT NULL DROP TABLE table4
CREATE TABLE Table4 (ID int, Name varchar(50), Class varchar(20), Date date, Intime time, Outtime time, INAM varchar(20), OUTPM varchar(20))
SELECT * FROM table1
SELECT * FROM table2
SELECT * FROM table3
INSERT INTO table4
SELECT t1.[ID], t1.[Name], t1.[Class], t2.[Date], t2.[Intime], NULL, t2.[INAM], NULL FROM table2 AS t2 JOIN table1 AS t1 ON t1.[ID] = t2.[ID]
UNION ALL
SELECT t1.[ID], t1.[Name], t1.[Class], t2.[Date], NULL, t2.[Outtime] , NULL, t2.[OUTPM] FROM table3 AS t2 JOIN table1 AS t1 ON t1.[ID] = t2.[ID]
SELECT * FROM table4

Answer 2

You almost certainly do not want a CROSS JOIN, you want an INNER JOIN. A CROSS JOIN gives you the Cartesian product, which is every possible combination of the rows. An INNER JOIN gives you the matching records.
Assuming that ID is a primary key in Table2 and Table3, then something like this:
INSERT INTO Table4 ([ID], [Name], [Class], [Date], [Intime], [Outtime], [INAM], [OUTPM])
SELECT t2.[ID], y2.[Name], t2.[Class], t2.[Date], t2.[Intime], t3.[Outtime], t2.[INAM], t3.[OUTPM]
FROM Table2 AS t2
INNER JOIN Table3 AS t3 ON t2.ID = t3.ID;
Your sample data is very limited, but what is shown is an INNER JOIN.