I have a DB2 table with two columns A and B storing alphanumeric values.I want to find whether a value(MyValue) exist in between A and B. I want my result to be : MyValue | A | B
I could have used: SELECT 'MyValue',A,B FROM TABLENAME WHERE(A < 'MyValue' AND B > 'MyValue') but the constraint is, I have to search more than 10000 values with single query and want the result as below format.
Ex. value=W140686,0032090,0045790...etc
Expected Result:
MyValue A B
W140686 | W000000 | W999999
0032090 | 0000001 | 0500000
0045790 | 0000001 | 0500000
..
..
..
Any help / suggestion would be highly appreciated.
Thanks in advance.
The BETWEEN predicate includes the end points. In this case, the result set will include the string 'MyValue' if it's equal to either the string in column A or the string in column B.
SELECT 'MyValue',A,B
FROM TABLENAME
WHERE 'MyValue' BETWEEN A AND B;
If you want to exclude the end points . . .
SELECT 'MyValue',A,B
FROM TABLENAME
WHERE 'MyValue' > A AND 'MyValue' < B;
For performance, you might want one index on the pair of columns {A, B}. For details, read the execution plan.
If you need to supply 10000 values to the WHERE clause, you should probably store them in a temporary table. Join the temporary table to TABLENAME.
-- DB2 syntax to create a temporary table is different. Look it up.
create temp table my_values (
MyValue varchar(10) primary key
);
-- Insert the 10000 values here.
insert into my_values values
('W140686'),('0032090'), ('0045790');
select T1.MyValue, T2.a, T2.b
from my_values T1
inner join TABLENAME T2
on T1.MyValue > T2.a and T1.MyValue < T2.b
The join predicate is the same as the WHERE clause in my earlier queries.
Related
I am trying to tidy up a database removing duplicates.
Let's say I have a database that looks like this one
Date | Value1 | Value2
01/01/2018 A B
01/01/2018 B A
02/01/2018 A B
In this case, according to my needs, the first two rows are identical, so I would like to drop one (let's say the second one). If I use SELECT DISTINCT it won't drop it because they are, in fact, different.
Is there an easy procedure to do so?
Thank you
You could use the exists operator to find (and delete!) them:
DELETE FROM mytable a
WHERE EXISTS (SELECT *
FROM mytable b
WHERE a.value1 = b.value2 AND
a.value2 = b.value1 AND
a.value1 < b.value1)
Here's one possibility:
create table t(date,value1,value2);
insert into t values
('01/01/2018','A','B'),
('01/01/2018','B','A'),
('02/01/2018','A','B');
select distinct date,min(value1,value2) value1,max(value1,value2) value2 from t;
I have a table in which there can be two newspaper publishing dates for a particular value which is inserted in a single column only under NewsPaperDate. All the remaining values get duplicated. Now I have to write a query in which the two NewsPaperDate values should be shown in a single row under two columns, NewsPaperDate1 and NewsPaperDate2, with the remaining values. Can anyone help in this? The DataBase is Sql Server
The Table structure is
You need to join the table to itself. There are different ways of doing this but based on your screenshot you could do:
select
a.yonja_no,
a.newspaper_date as newspaperdate1,
b.newspaper_date as newspaperdate2
from newspapertable a, newspapertable b
where a.yonja_no = b.yonja_no
and a.newspapere_s > b.newspapere_s
;
(Edited: see comments)
check fiddle link for query execution with sample data
create table tab1(newspaperDate number,b number,c number);
INSERT INTO tab1 VALUES(1,2,3);
INSERT INTO tab1 VALUES(2,2,3);
INSERT INTO tab1 VALUES(3,3,4);
SELECT t1.newspaperDate AS date1,t2.newspaperDate AS date2 , t1.b AS b1,t1.c AS c1 FROM tab1 t1 , tab1 t2
WHERE t1.newspaperDate < t2.newspaperDate AND t1.b=t2.b ;
OUTPUT
| DATE1 | DATE2 | B1 | C1 |
---------------------------
| 1 | 2 | 2 | 3 |
Joining a table to itself is the best approach for your query. Read
this
http://www.thunderstone.com/site/texisman/joining_a_table_to_itself.html
I'm trying to figure out how to fill in values that are missing from one column with the non-missing values from other rows that have the same value on a given column. For instance, in the below example, I'd want all the "1" values to be equal to Bob and all of the "2" values to be equal to John
ID # | Name
-------|-----
1 | Bob
1 | (null)
1 | (null)
2 | John
2 | (null)
2 | (null)
`
EDIT: One caveat is that I'm using postgresql 8.4 with Greenplum and so correlated subqueries are not supported.
CREATE TABLE bobjohn
( ID INTEGER NOT NULL
, zname varchar
);
INSERT INTO bobjohn(id, zname) VALUES
(1,'Bob') ,(1, NULL) ,(1, NULL)
,(2,'John') ,(2, NULL) ,(2, NULL)
;
UPDATE bobjohn dst
SET zname = src.zname
FROM bobjohn src
WHERE dst.id = src.id
AND dst.zname IS NULL
AND src.zname IS NOT NULL
;
SELECT * FROM bobjohn;
NOTE: this query will fail if more than one name exists for a given Id. (and it won't touch records for which no non-null name exists)
If you are on a postgres version >-9, you could use a CTE to fetch the source tuples (this is equivalent to a subquery, but is easier to write and read (IMHO). The CTE also tackles the duplicate values-problem (in a rather crude way):
--
-- CTE's dont work in update queries for Postgres version below 9
--
WITH uniq AS (
SELECT DISTINCT id
-- if there are more than one names for a given Id: pick the lowest
, min(zname) as zname
FROM bobjohn
WHERE zname IS NOT NULL
GROUP BY id
)
UPDATE bobjohn dst
SET zname = src.zname
FROM uniq src
WHERE dst.id = src.id
AND dst.zname IS NULL
;
SELECT * FROM bobjohn;
UPDATE tbl
SET name = x.name
FROM (
SELECT DISTINCT ON (id) id, name
FROM tbl
WHERE name IS NOT NULL
ORDER BY id, name
) x
WHERE x.id = tbl.id
AND tbl.name IS NULL;
DISTINCT ON does the job alone. Not need for additional aggregation.
In case of multiple values for name, the alphabetically first one (according to the current locale) is picked - that's what the ORDER BY id, name is for. If name is unambiguous you can omit that line.
Also, if there is at least one non-null value per id, you can omit WHERE name IS NOT NULL.
If you know for a fact that there are no conflicting values (multiple rows with the same ID but different, non-null names) then something like this will update the table appropriately:
UPDATE some_table AS t1
SET name = (
SELECT name
FROM some_table AS t2
WHERE t1.id = t2.id
AND name IS NOT NULL
LIMIT 1
)
WHERE name IS NULL;
If you only want to query the table and have this information filled in on the fly, you can use a similar query:
SELECT
t1.id,
(
SELECT name
FROM some_table AS t2
WHERE t1.id = t2.id
AND name IS NOT NULL
LIMIT 1
) AS name
FROM some_table AS t1;
If I have to search for some data I can use wildcards and use a simple query -
SELECT * FROM TABLE WHERE COL1 LIKE '%test_string%'
And, if I have to look through many values I can use -
SELECT * FROM TABLE WHERE COL1 IN (Select col from AnotherTable)
But, is it possible to use both together. That is, the query doesn't just perform a WHERE IN but also perform something similar to WHERE LIKE? A query that just doesn't look through a set of values but search using wildcards through a set of values.
If this isn't clear I can give an example. Let me know. Thanks.
Example -
lets consider -
AnotherTable -
id | Col
------|------
1 | one
2 | two
3 | three
Table -
Col | Col1
------|------
aa | one
bb | two
cc | three
dd | four
ee | one_two
bb | three_two
Now, if I can use
SELECT * FROM TABLE WHERE COL1 IN (Select col from AnotherTable)
This gives me -
Col | Col1
------|------
aa | one
bb | two
cc | three
But what if I need -
Col | Col1
------|------
aa | one
bb | two
cc | three
ee | one_two
bb | three_two
I guess this should help you understand what I mean by using WHERE IN and LIKE together
SELECT *
FROM TABLE A
INNER JOIN AnotherTable B on
A.COL1 = B.col
WHERE COL1 LIKE '%test_string%'
Based on the example code provided, give this a try. The final select statement presents the data as you have requested.
create table #AnotherTable
(
ID int IDENTITY(1,1) not null primary key,
Col varchar(100)
);
INSERT INTO #AnotherTable(col) values('one')
INSERT INTO #AnotherTable(col) values('two')
INSERT INTO #AnotherTable(col) values('three')
create table #Table
(
Col varchar(100),
Col1 varchar(100)
);
INSERT INTO #Table(Col,Col1) values('aa','one')
INSERT INTO #Table(Col,Col1) values('bb','two')
INSERT INTO #Table(Col,Col1) values('cc','three')
INSERT INTO #Table(Col,Col1) values('dd','four')
INSERT INTO #Table(Col,Col1) values('ee','one_two')
INSERT INTO #Table(Col,Col1) values('ff','three_two')
SELECT * FROM #AnotherTable
SELECT * FROM #Table
SELECT * FROM #Table WHERE COL1 IN(Select col from #AnotherTable)
SELECT distinct A.*
FROM #Table A
INNER JOIN #AnotherTable B on
A.col1 LIKE '%'+B.Col+'%'
DROP TABLE #Table
DROP TABLE #AnotherTable
Yes. Use the keyword AND:
SELECT * FROM TABLE WHERE COL1 IN (Select col from AnotherTable) AND COL1 LIKE '%test_string%'
But in this case, you are probably better off using JOIN syntax:
SELECT TABLE.* FROM TABLE JOIN AnotherTable on TABLE.COL1 = AnotherTable.col WHERE TABLE.COL1 LIKE '%test_string'
no because each element in the LIKE clause needs the wildcard and there's not a way to do that with the IN clause
The pattern matching operators are:
IN, against a list of values,
LIKE, against a pattern,
REGEXP/RLIKE against a regular expression (which includes both wildcards and alternatives, and is thus closest to "using wildcards through a set of valuws", e.g. (ab)+a|(ba)+b will match all strings aba...ba or bab...ab),
FIND_IN_SET to get the index of a string in a set (which is represented as a comma separated string),
SOUNDS LIKE to compare strings based on how they're pronounced and
MATCH ... AGAINST for full-text matching.
That's about it for string matching, though there are other string functions.
For the example, you could try joining on Table.Col1 LIKE CONCAT(AnotherTable.Col, '%'), though performance will probably be dreadful (assuming it works).
Try a cross join, so that you can compare every row in AnotherTable to every row in Table:
SELECT DISTINCT t.Col, t.Col1
FROM AnotherTable at
CROSS JOIN Table t
WHERE t.col1 LIKE ('%' + at.col + '%')
To make it safe, you'll need to escape wildcards in at.col. Try this answer for that.
If I understand the question correctly you want the rows from "Table" when "Table.Col1" is IN "AnotherTable.Col" and you also want the rows when Col1 IS LIKE '%some_string%'.
If so you want something like:
SELECT
t.*
FROM
[Table] t
LEFT JOIN
[AnotherTable] at ON t.Col1 = at.Col
WHERE (at.Col IS NOT NULL
OR t.Col1 LIKE '%some_string%')
Something like this?
SELECT * FROM TABLE
WHERE
COL1 IN (Select col from AnotherTable)
AND COL1 LIKE '%test_string%'
Are you thinking about something like EXISTS?
SELECT * FROM TABLE t WHERE EXISTS (Select col from AnotherTable t2 where t2.col = t.col like '%test_string%' )
i need Add Row Numbers To a SELECT Query without using Row_Number() function.
and without using user defined functions or stored procedures.
Select (obtain the row number) as [Row], field1, field2, fieldn from aTable
UPDATE
i am using SAP B1 DIAPI, to make a query , this system does not allow the use of rownumber() function in the select statement.
Bye.
I'm not sure if this will work for your particular situation or not, but can you execute this query with a stored procedure? If so, you can:
A) Create a temp table with all your normal result columns, plus a Row column as an auto-incremented identity.
B) Select-Insert your original query, sans the row column (SQL will fill this in automatically for you)
C) Select * on the temp table for your result set.
Not the most elegant solution, but will accomplish the row numbering you are wanting.
This query will give you the row_number,
SELECT
(SELECT COUNT(*) FROM #table t2 WHERE t2.field <= t1.field) AS row_number,
field,
otherField
FROM #table t1
but there are some restrictions when you want to use it. You have to have one column in your table (in the example it is field) which is unique and numeric and you can use it as a reference. For example:
DECLARE #table TABLE
(
field INT,
otherField VARCHAR(10)
)
INSERT INTO #table(field,otherField) VALUES (1,'a')
INSERT INTO #table(field,otherField) VALUES (4,'b')
INSERT INTO #table(field,otherField) VALUES (6,'c')
INSERT INTO #table(field,otherField) VALUES (7,'d')
SELECT * FROM #table
returns
field | otherField
------------------
1 | a
4 | b
6 | c
7 | d
and
SELECT
(SELECT COUNT(*) FROM #table t2 WHERE t2.field <= t1.field) AS row_number,
field,
otherField
FROM #table t1
returns
row_number | field | otherField
-------------------------------
1 | 1 | a
2 | 4 | b
3 | 6 | c
4 | 7 | d
This is the solution without functions and stored procedures, but as I said there are the restrictions. But anyway, maybe it is enough for you.
RRUZ, you might be able to hide the use of a function by wrapping your query in a View. It would be transparent to the caller. I don't see any other options, besides the ones already mentioned.