I have two tables each with multiple columns.
+------+-------+--+
| Col1 | Col2 | |
+------+-------+--+
| 1 | 1231 | |
| 2 | 123 | |table 1
| 3 | 14124 | |
+------+-------+--+
+------+-------+--+
| Col3 | Col4 | |table 2
+------+-------+--+
| 1 | 1231 | |
| 2 | 323 | |
| 3 | 14324 | |
+------+-------+--+
I want to check is if col1 and col3 are identical. That is: all the values match, to be determined using sql?
I dont want to use except and also I don't want to take difference of the two columns and check if its zero.
Is there a more efficient way to do this?
Am I missing something? Can't you join the tables together and compare?
select
...
from table1
inner join table2
on table1.col1 = table2.col3
You can outer join them and filter on null results
select table_1.col1, table_2.col3
from table_1 full outer join table_2 on table_1.col1, table_2.col3
where table_1.col1 is null
or table_2.col3 is null
This will give you all records where one of the values of either column does not exist in the other table.
Related
I hope everyone is doing well. I have a dilemma that i can not quite figure out.
I am trying to find a unique value for a field that is not a duplicate.
For example:
Table 1
|Col1 | Col2| Col3 |
| 123 | A | 1 |
| 123 | A | 2 |
| 12 | B | 1 |
| 12 | B | 2 |
| 12 | C | 3 |
| 12 | D | 4 |
| 1 | A | 1 |
| 2 | D | 1 |
| 3 | D | 1 |
Col 1 is the field that would have the duplicate values. Col2 would be the owner of the value in Col 1. Col 3 uses the row number() Over Partition syntax to get the numbers in ascending order.
The goal i am trying to accomplish is to remove the value in col 1 if it is not truly unique when looking at col2.
Example:
Col1 has the value 123, Col2 has the value A. Although there are two instances of 123 being owned by A, i can determine that it is indeed unique.
Now look at Col1 that has the value 12 with values in Col2 of B,C,D.
Value 12 is associated with three different owners thus eliminating 12 from our result list.
So in the end i would like to see a result table such as this :
|Col1 | Col2|
| 123 | A |
| 1 | A |
| 2 | D |
| 3 | D |
To summarize, i would like to first use the partition numbers to identify if the value in col1 is repeated. From there i want to verify that the values in col 2 are the same. If so the value in col 1 and col 2 remains as one single entry. However if the values in col 2 do not match, all records for the col1 value are removed.
I will provide the syntax code for my query if needed.
Update**
I failed to mention that table 1 is the result of inner joining two tables.
So Col1 comes from table a and Col2 comes from table b.
The values in table a for col2 are hard to interpret so i had to make sense of them and assigned it proper name values.
The join query i used to combine the two are:
Select a.Col1, B.Col2 FROM Table a INNER JOIN Table b on a.Colx = b.Colx
Update**
Table a:
|Col1 | Colx| Col3 |
| 123 | SMS | 1 |
| 123 | S9W | 2 |
| 12 | NAV | 1 |
| 12 | NFR | 2 |
| 12 | ABC | 3 |
| 12 | DEF | 4 |
| 1 | SMS | 1 |
| 2 | DEF | 1 |
| 3 | DES | 1 |
Table b:
|Colx | Col2|
| SMS | A |
| S9W | A |
| DEF | D |
| DES | D |
| NAV | B |
| NFR | B |
| ABC | C |
Above are sample data for both tables that get joined in order to create the first table displayed in this body.
Thank you all so much!
NOT EXISTS operator can be used to do this task:
SELECT distinct Col1 , Col2
FROM table t
WHERE NOT EXISTS(
SELECT 1 FROM table t1
WHERE t.col1=t1.col1 AND t.col2 <> t1.col2
)
If I understand correctly, you want:
select col1, min(col2)
from t
group by col1
where min(col2) <> max(col2);
I think the third column is confusing you. It doesn't seem to play any role in the logic you want.
Apologies for this but SQL is not a strong point for me, and whilst appears similar to lots of other queries I cannot translate those to this situation successfully.
I have two tables that will be related by a common value (id and Issue) if a row in table 2 exists.
I need to get a distinct count of users raising particular issues. I have users in both tables, with the table 2 user taking precedence if it exists.
There is always a REPORTER in Table 1, but there may not be a Stringvalue of Name (fieldtype = 1) in table 2. If there is a Stringvalue then that is the "User" and the Reporter can be ignored.
Table 1
| id | Reporter| Type |
| 1 | 111111 | 1 |
| 2 | 111111 | 2 |
| 3 | 222222 | 2 |
| 4 | 333333 | 1 |
| 5 | 111111 | 1 |
| 6 | 666666 | 1 |
Table 2
|issue | Stringvalue | fieldType|
| 1 | Fred | 1 |
| 1 | bananas | 2 |
| 2 | Jack | 1 |
| 5 | Steve | 1 |
I have a total of 4 issues of the right type (1,4,5,6), three reporters (111111,333333,666666) and two Stringvalues(Fred, Steve).
My total count of Distinct Users = 4 (Fred, 333333, Steve, 666666)
Result Table
| id| T1.Reporter | T2.Name |
| 1| Null | Fred |
| 4| 333333 | Null |
| 5| Null | Steve |
| 6| 666666 | Null |
How do I get this result in SQL!
Closest try so far:
SELECT
table1.REPORTER,
TO_CHAR(NULL) "NAME"
FROM table1
Where table1.TYPE =1
AND table1.REPORTER <> '111111'
Union
SELECT
TO_CHAR(NULL) "REPORTER",
table2.STRINGVALUE "NAME"
FROM table2,
table1
WHERE table2.ISSUE = table1.ID
AND table2.fieldtype= 1
and table1.issuetype = 1
Without explicitly excluding the default table 1 Reporter, this gets returned in my results even when there is a name value in table 2.
I have tried exists and in but cannot get syntax right or the correct results. As soon as try any Join that links the ID and Issue values the results always end up constrained to the matching rows or for all values. And added additional conditions to the ON does not return correct results.
I have tried too many permutations to list, logically this sounds like should be able to do union with where exists, or left outer join but my skills are lacking to make this work.
You need to use a LEFT JOIN and that is where you specify the fieldtype = 1 clause:
SELECT
table1.id,
CASE
WHEN table2.Stringvalue IS NOT NULL THEN table2.Stringvalue
ELSE table1.Reporter
END AS TheUser
FROM table1
LEFT JOIN table2 ON table1.id = table2.issue AND table2.fieldType = 1
WHERE table1.Type = 1
Result:
+------+---------+
| id | TheUser |
+------+---------+
| 1 | Fred |
| 4 | 333333 |
| 5 | Steve |
| 6 | 666666 |
+------+---------+
If I understand correctly, you want a left join and count(distinct). Here is what I think you are looking for:
select count(distinct coalesce(stringval, reporter) )
from table1 t1 left join
table2 t2
on t1.id = t2.issue and t2.fieldtype = 1
where t1.id in (1, 4, 5, 6);
You need to learn how to use explicit JOIN syntax. As a simple rule: Never use commas in the FROM clause. Always use explicit JOIN syntax. For one thing, it is more powerful, making it easy to express outer joins.
I'm not quite sure how to properly phrase the question, but I am basically trying to develop an SQL query that SELECTs information from this table:
-------------------
| id | Val | Date |
|----|-----|------|
| 1 | A | 10/9 |
| 1 | B | 3/14 |
| 2 | A | 1/6 |
| 3 | A | 4/4 |
| 4 | B | 7/12 |
| 5 | A | 8/6 |
-------------------
And produces a table that looks like this:
------------------------------------------------
| id | Val_1 | Val_1_Date | Val_2 | Val_2_Date |
|----|-------|------------|-------|-------------
| 1 | A | 10/9 | B | 3/14 |
| 2 | A | 1/6 | | |
| 3 | A | 4/4 | | |
| 4 | | | B | 7/12 |
| 5 | A | 8/6 | | |
------------------------------------------------
I have already begun and developed the query to pull out the values in the Val fields into distinct columns:
SELECT * FROM
(
SELECT id, MAX(SWITCH( val='A', 'A')) as Val_1,
MAX(SWITCH( val='B', 'B')) as Val_2
FROM table1 GROUP BY id
)a
WHERE Val_1 IS NULL OR Val_2 IS NULL;
How would I expand on this to pull out their associated dates?
(I am using SWITCH() instead of CASE WHEN because I am using a driver similar to that of MS Access.)
Thanks!
I think following should work:
select id, SWITCH( val='A', 'A') as Val_1, SWITCH( val='A', Date) as Val_1_Date, SWITCH( val='B', 'B') as Val_2, SWITCH( val='B', Date) as Val_2_Date FROM table1 GROUP BY id
I do not prefer switches, so here is a query that does what you want without switches. This also answers your previous question.
Select distinct table1.ID, tableA.Val as Val_1, tableA.Date as Val_1_Date,
tableB.Val as Val_2, tableB.Date as Val_2_Date
FROM table1 left outer join
table1 as tableA on table1.id = tableA.id and tableA.Val = 'A' left outer join
table1 as tableB on table1.id = tableB.id and tableB.Val = 'B'
You can use ISNULL if that is preferred. This works because the first tables selects a distinct column of ID's, and the two joins get the A and B values. When creating selects using this method, make sure that you use tableA.Val = 'A' in the join conditions, and not in the where clause. Having tableA.Val = 'A' in the where clause will filter out all NULL's.
I've tables related with foreign keys and i try to prepare a view to compose them via inner joins on SQL Server. I don't know if using inner join's is the way, but I can't get what I want anyway.
Tables are like below (I have more than 2 tables):
Table1:
| ID | Bla Bla... |
Table2:
| ID | Table1ID | Bla Bla... |
The query I tried is like this:
Select
Table1.ID, COUNT(Table2.ID) as FooCount
From
Table1
Inner Join
Table2 on Table2.Table1ID = Table1.ID
The result I want to see should be this:
| ID | FooCount |
-----------------------
| 1 | 45 |
| 2 | 75 |
| 3 | 98 |
| 4 | 100 |
| 5 | 11 |
| 6 | 37 |
How can I do this?
You don't even need a join to do this:
SELECT Table1Id AS ID, COUNT(*) as FooCount FROM Table2 GROUP BY Table1Id
I have two tables:
T1:
| M_ID | P_ID1 | P_ID2 | rest of T1 columns |
| 0 | 0 | 1 | ... |
| 1 | 2 | 3 | ... |
T2:
| P_ID | Type | A | B |
| 0 | 1 | a | e |
| 1 | 2 | b | f |
| 2 | 1 | c | g |
| 3 | 2 | d | h |
Now, I want to have a query that selects this:
| M_ID | P_1a | P_1b | P_2a | P_2b | rest of T1 columns |
| 0 | a | e | b | f | ... |
| 1 | c | g | c | h | ... |
So, in words: I want to select all columns from T1, but I want to replace P_ID1 with the columns from T2, where the P_ID is equal to P_ID1, and the type is 1, and basically the same for P_ID2.
I can obviously get the information I need with multiple queries, but I was wondering if there is a way that I can do this with one query. Any ideas?
I'm currently using SQL Server 2008r2, but I'd also be interested in solutions for other database software.
Thanks for the help!
Sure, you just need to use a join:
select T1.M_ID, t2_1.A as P_1a, t2_1.B as P_1b, t2_2.A as P_2a, t2_2.B as P_2b, ...
from T1, T2 t2_1, T2 t2_2
where T1.P_ID1 = t2_1.P_ID and T1.P_ID2 = t2_2.P_ID
basically we are joining T1 onto T2 twice, once for the P_1 values and a second time for the P_2 values. You need to alias T2 when you join it twice to distinguish between the two (that's what the t2_1 and t2_2 are - a means of distinguishing between the two instances of the joined T2).
This is the same as #John Pickup's solution only using modern join syntax:
select T1.M_ID, t2_1.A as P_1a, t2_1.B as P_1b, t2_2.A as P_2a, t2_2.B as P_2b, ...
from T1
join T2 t2_1 on T1.P_ID1 = t2_1.P_ID
join T2 t2_2 on T1.P_ID2 = t2_2.P_ID
I only post a seperate answer, as there is no code formatting in comments as you get told here