I am learning SQL Basics..So If my Answer is wrong Plz do
reply to tht,
In the First Query Where 1=1 implies Show all where The
first coloum element is equal to 1
and second query show all from table
Both are returns the SAME results.
I dont know the meaning of the
SELECT * FROM Table_Name WHERE 1=1
SELECT * FROM Table_Name WHERE 2=2
SELECT * FROM Table_Name WHERE 5=5
SELECT * FROM Table_Name WHERE 100=100
.
.
.
etc..,
It accepts the where both are equal.
If you give like
SELECT * FROM Table_Name WHERE 100=1001
It is not accept.
hey! I too agree there wont be any difference in result it
displays but the performance will be different. While
executing the first query the where condition to be checked
for each record it displays hence it takes much time to
execute while compared with question no 2 i.e, without
where condition. this is what I believe in.
Of course, both the Queries will get you the same data but,
When compared to the first case processing time will be
slightly reduced in the second case.
Bytes sent from client and Bytes received from server will
be more in the first case.
and one more thing is better not using "select * from ..."
i have 4 tables.. T1, T2, T3, T4..
these tables have the same structure and they store the
information entered in different years..
T1 stored 2002, T2 stored 2003, T3 stored 2004 and T4 stored
2005..
i want to copy contents in T1 to T2, T2 to T3, T3 to T4 and
T4 to T1..
how do i do that? Temp tables cannot be used..