SQL to make new column(mySQL)

Question

I got two sql statements:

SELECT username AS userA FROM WHERE username='abc'
SELECT username AS userB FROM WHERE username='abcd' AND password='abcd'

I want to output the result as below:

userA  |  userB
----------------
abc    |  abcd

How to combine two SQL statements?

I don't think you can join them like that. The closest I know of is a union, which will select them as two rows instead of two columns. — Richard Theobald
– Richard Theobald, Commented Feb 2, 2016 at 1:49
Why are you selecting the username when you already know what it is? (The value is in the where clause.) — Gordon Linoff
– Gordon Linoff, Commented Feb 2, 2016 at 1:52
Can you provide us with some table structure? The easiest way to handle this would be to join the two tables together. — Tim Biegeleisen
– Tim Biegeleisen, Commented Feb 2, 2016 at 1:52

uh_big_mike_boi · Accepted Answer · 2016-02-02 02:12:22Z

1

SELECT tableA.username as userA
    tableB.username as userB
FROM tableA
CROSS JOIN table B
WHERE tableA.username='abc'
    AND tableB.username='abcd'
    AND tableB.password='abcd';

CROSS JOIN! :P CARTESIAN PRODUCT!

answered Feb 2, 2016 at 2:12

uh_big_mike_boi

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ffflabs · Accepted Answer · 2016-02-02 01:52:54Z

1

You can combine tables and fields with the syntax:

SELECT tableA.username as userA
    tableB.username as userB
FROM tableA
JOIN table B
WHERE tableA.username='abc'
    AND tableB.username='abcd'
    AND tableB.password='abcd';

Unless there's some kind of relation between the tables, you'll be getting the cross product times rows, so it might be an NxM result which is just useless.

answered Feb 2, 2016 at 1:52

ffflabs

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Zamrony P. Juhara · Accepted Answer · 2016-02-02 02:01:12Z

1

I haven't try it but here something you can try:

SELECT 
  (SELECT username AS userA FROM WHERE username='abc' LIMIT 1) AS 'userA',
  (SELECT username AS userB FROM WHERE username='abcd' AND password='abcd' LIMIT 1) AS 'userB';

answered Feb 2, 2016 at 2:01

Zamrony P. Juhara

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Raffaello.D.Huke · Accepted Answer · 2016-02-02 02:06:19Z

1

try this:

select t1.userA,t2.userB  
 from
      (SELECT username AS userA FROM WHERE username='abc')t1
 join (SELECT username AS userB FROM WHERE username='abcd' AND password='abcd')t2
 where 1=1

where 1=1 will combine any 2 queries without condition but it's meaningless. Although it match what you asked i don't suggest people use it

answered Feb 2, 2016 at 2:06

Raffaello.D.Huke

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