SQL查询，从多个表中获取数据和查询结果

Question

I have a table T1, which contains which contains columns (A , B, C ,D) in which A is PK.

And I have some more tables. And I want to get some data from these tables. I get the data as per my sql query from these tables. Sql query (query1) is as follows

select t3.col1 as A, t3.col4 as F, t4.col as H
from t3, t4
where  t3.col1 = t4.col2;

Now I want to get data from Table T1 and above query1 result.

select B , C , D , F,  H
from T1, Temp
where t1.A = Temp.A;

where Temp is the above sql query1 result.

How I can achieve this?

Any suggestions.

Answer 1

try this

SELECT t1.B as B, t1.C as B, t1.D as D, t3.col4 as F, t4.col as H
FROM t1, t3, t4
WHERE t1.A=t3.col1 AND t3.col1=t4.col2

Answer 2

I'd suggest using explicit join as in:

select t1.B, t1.C, ..., t3.col1 as A, t3.col4 as F, t4.col as H
from t3
join t4
    on t3.col1 = t4.col2
join t1
    on t1.A = t3.col1;

Answer 3

Use inner join

consider this exapmle

lets say two table 1st one is "Order" and 2nd is "Customer"

SELECT Orders.OrderID(table_name.column_name), Customers.CustomerName(table_name.column_name), Orders.OrderDate(table_name.column_name) FROM Orders(1st table_name) INNER JOIN Customers(2nd table_name) ON Orders.CustomerID=Customers.CustomerID(Must be matching field for joining);