I'm trying to compare two tables in a DB2 database in z/OS using SPUFI to submit SQL queries.
I'm doing this by using EXCEPT to see the difference between two SELECT queries.
I need to filter the SELECT statement from the first query with a WHERE clause.
SELECT KEY_FIELD_1,LOOKUP_FIELD_1
FROM TABLE_1
WHERE FILTER_FIELD = '1'
EXCEPT
SELECT KEY FIELD_2,LOOKUP_FIELD_2
FROM TABLE_2
I got results back, but it also returned an error -199 Is this because the WHERE clause is not present in the second SELECT statement?
ERROR: ILLEGAL USE OF KEYWORD EXCEPT.
TOKEN <ERR_STMT> <WNG_STMT> GET SQL
SAVEPOINT HOLD FREE ASSOCIATE WAS EXPECTED
Try introducing parentheses e.g.
( SELECT KEY_FIELD_1,LOOKUP_FIELD_1
FROM TABLE_1
WHERE FILTER_FIELD = '1' )
EXCEPT
( SELECT KEY FIELD_2,LOOKUP_FIELD_2
FROM TABLE_2 )
Related
I'm using t-sql,
I have two separate select statements. The first one involves nested queries based on parameters passed to the nested query.
Can i use the results of the first select statement as a table to use the "EXCEPT" operator or JOIN operator to connect with the select result set coming from the 2nd select statement in the format:
select col1,col2,col3 from tableOne where col3=(nested queries) as table1
<EXCEPT/JOIN>
select col3,col4,col5 from tableOne where col2=(nested queries) as table2
"as table1/2" gives me errors and "EXCEPT" key word, only excepts one column to do the comparison Are there better approaches for this?
how do i filter a column col1 with multiple values
select * from table where col1=2 and col1=4 and userID='740b9738-63d2-67ff-ba21-801b65dd0ae1'
i tired
select * from table where col1=2 or col1=4 and userID='740b9738-63d2-67ff-ba21-801b65dd0ae1'
the result of both queries is incorrect
the first one gives zero results
second one gives 3 results
the correct is 2 results
the sql will run against the sqlite db.
AND is evaluated before OR, so your query is equivalent to:
select *
from table
where col1=2 or (col1=4 and userID='740b9738-63d2-67ff-ba21-801b65dd0ae1')
You need to explicitly group the conditions when mixing AND and OR:
select *
from table
where (col1=2 or col1=4) and userID='740b9738-63d2-67ff-ba21-801b65dd0ae1'
I'm using Sybase ASE 12.5.0.3 and I'm unable to do subqueries like:
select * from (select '1' union select '2' ) X
I've been looking around and as far as I know it should be possible after Sybase ASE 12, am I doing something wrong, or is it not possible with this version???
Edit - Even after changing the query to:
select * from (select '1' as col1 union select '2' as col1 ) X
So even giving alias to the columns, it fails anyways...
Without seeing an error message, it appears that you need to give column aliases in your sub-query:
select *
from
(
select '1' as yournewCol
union
select '2' as yournewCol
) X
You need to give your columns name. Try this:
Sybase ASE does not support subqueries in the FROM clause:
Subqueries can be nested inside the where or having clause of an outer select, insert, update, or delete statement, inside another subquery, or in a select list. Alternatively, you can write many statements that contain subqueries as joins; Adaptive Server processes such statements as joins.
I have an Oracle query, which has something to the effect of
Having Count(field) > (Long SQL statement that returns one row)
Both sides of the query work alone, but together I get a "not a group by" expression.
When replacing the long SQL statement with a number it works, but I assumed the two were equivalent if only one row is returned?
Edit
After doing some playing around I realized:
... Table T ... Having Count(field) > (Long SQL statement with Table A Where A.field = T.field)
It works when I replace T.field with any of the specific options for T.field, but when I reference T.field specifically I get the same "not a group by expression"
When Oracle parses your query it doesn't know if the query is going to return only one row or a bunch of rows. So simply append group by your_column to the end of your query.
For example this query returns one row:
select count(*) from user_objects;
But if I wanted to include sysdate along with that, I would have to do
select
sysdate the_date,
count(*)
from
user_objects
group by
the_date;
SELECT ...
FROM Table T ...
GROUP BY T.afield
HAVING Count(T.anotherfield)
> (Long SQL statement with Table A Where A.somefield = T.afield)
should work ok.
SELECT ...
FROM Table T ...
GROUP BY T.anotherfield
HAVING Count(T.anotherfield)
> (Long SQL statement with Table A WHERE A.somefield = T.afield)
should not work. A field (like T.afield) that is not included in the GROUP BY list, cannot be referenced in SELECT, HAVING or ORDER BY clauses. Only aggregate functions of that field can be referenced - you could have WHERE A.somefield = MIN(T.afield) for example.
Could someone please explain to me why the following query is invalid? I'm running this query against an Oracle 10g database.
select count(test.*) from my_table test;
I get the following error: ORA-01747: invalid user.table.column, table.column, or column specification
however, the following two queries are valid.
select count(test.column) from my_table test;
select test.* from my_table test;
COUNT(expression) will count all rows where expression is not null. COUNT(*) is an exception, it returns the number of rows: * is not an alias for my_table.*.
As far as I know, Count(Table.*) is not officially supported in the SQL specification. Only Count(*) (count all rows returned) and Count(Table.ColumnName) (count all non-null values in the given column). So, even if the DBMS supported it, I would recommend against using it.`
This syntax only works in PostgreSQL and only because it has a record datatype (for which test.* is a meaningful expression).
Just use COUNT(*).
This query:
select count(test.column) from my_table test;
will return you the number of records for which test.column is not NULL.
This query:
select test.* from my_table test;
will just return you all records from my_table.
COUNT as such is probably the only aggregate that makes sense without parameters, and using an expression like COUNT(*) is just a way to call a function without providing any actual parameters to it.
You might reasonably want to find the number of records where test.column is not NULL if you are doing an outer join. As every table should have a PK (which is not null) you should be able to count the rows like that if you want:
select count(y.pk)
from x
left outer join y on y.pk = x.ck
COUNT(*) is no good here because the outer join is creating a null row for the table that is deficient in information.