I have two tables,PRODUCTS AND LOOKUP TABLES.Now i want to order the KEY Column in products table based on KEY column value in LOOKUP TABLE.
CREATE TABLE PRODUCTS
(
ID INT,
KEY VARCHAR(50)
)
INSERT INTO PRODUCTS
VALUES (1, 'EGHS'), (2, 'PFE'), (3, 'EGHS'),
(4, 'PFE'), (5, 'ABC')
CREATE TABLE LOOKUP (F_KEY VARCHAR(50))
INSERT INTO LOOKUP VALUES('PFE,EGHS,ABC')
Now I want to order the records in PRODUCTS table based on KEY (PFE,EGHS,ABC) values in LOOKUP table.
Example output:
PRODUCTS
ID F_KEY
-----------
2 PFE
4 PFE
1 EGHS
3 EGHS
5 ABC
I use this query, but it is not working
SELECT *
FROM PRODUCTS
ORDER BY (SELECT F_KEY FROM LOOKUP)
You can split the string using XML. You first need to convert the string to XML and replace the comma with start and end XML tags.
Once done, you can assign an incrementing number using ROW_NUMBER() like following.
;WITH cte
AS (SELECT dt,
Row_number()
OVER(
ORDER BY (SELECT 1)) RN
FROM (SELECT Cast('<X>' + Replace(F.f_key, ',', '</X><X>')
+ '</X>' AS XML) AS xmlfilter
FROM [lookup] F)F1
CROSS apply (SELECT fdata.d.value('.', 'varchar(500)') AS DT
FROM f1.xmlfilter.nodes('X') AS fdata(d)) O)
SELECT P.*
FROM products P
LEFT JOIN cte C
ON C.dt = P.[key]
ORDER BY C.rn
Online Demo
Output:
ID F_KEY
-----------
2 PFE
4 PFE
1 EGHS
3 EGHS
5 ABC
You may do it like this:
SELECT ID, [KEY] FROM PRODUCTS
ORDER BY
CASE [KEY]
WHEN 'PFE' THEN 1
WHEN 'EGHS' THEN 2
WHEN 'ABC' THEN 3
END
Related
I am working on oracle database.
We load customer data in source table which eventually migrates to target table.
Every time customer data is loaded in source table it is having a unique batch_id.
If we want to update some field in customer table, then we again load the same customer in source table but this time with different batch_id.
Now I want to know batch_id of the customer just before the latest batch_id.
Batch_id we take is usually the current date.
Use ROW_NUMBER analytic function
your sample data
select * from tab
order by 1,2
CUSTOMER_ID BATCH_ID
----------- -------------------
1 09.12.2019 00:00:00
1 10.12.2019 00:00:00
2 10.12.2019 00:00:00
Row_number assihns sequence number starting from 1 for each customer order descending on BATCH_ID - you are interested on one before the latest, i.e. the rows with the number 2.
with cust as (
select
customer_id, batch_id,
row_number() over (partition by customer_id order by batch_id desc) rn
from tab)
select CUSTOMER_ID, BATCH_ID
from cust
where rn = 2;
CUSTOMER_ID BATCH_ID
----------- -------------------
1 09.12.2019 00:00:00
It seems that you're basically looking for the second biggest value in the SOURCE table.
In this example code the SOURCE_TABLE represents the table containing same CUSTOMER_NO with different BATCH_NO:
create table source_table (customer_no integer, batch_no date);
insert into source_table values ('1', SYSDATE-2);
insert into source_table values ('1', SYSDATE-1);
insert into source_table values ('1', SYSDATE);
SELECT batch_no
FROM (
SELECT batch_no, row_number() over (order by batch_no desc) as row_num
FROM source_table
) t
WHERE row_num = 2
Where row_num = 2 represents the second biggest value in the table.
The query returns SYSDATE-1.
I've got a table as follows
Table1
ID Name Tag
-----------------
1 N1 2.1
2 N2 3.5
3 N1 3.5
4 N3 8.1
I create a new table Table2 with ID and Name (unique constraint) and I want to insert Table1's contents into Table2 avoiding duplicates, in the sense that I want only 1, 2 and 4 from Table1 in Table2.
I've tried this but it doesn't seem to work and I get the unique constraint error (ORACLE SQL)
INSERT INTO TABLE2 (ID, NAME)
SELECT ID, NAME
FROM TABLE1
WHERE NAME NOT IN (SELECT NAME FROM TABLE2);
Please can someone point me in the right direction?
Sorry for not making myself clear. Table2 is a brand new table. I want the first values inserted, the following duplicates should be ignored. So in my case, N1, N2 get inserted, N1 is dupe so it is ignored, N3 is inserted
OK - from your description, I understand table t2 is currently empty, and you want to copy the rows where id is in (1, 2, 4) from table t1 to table t2.
Why your code fails:
You seem to believe that the condition is applied to the first row in t1, it passes so it is inserted into t2, then the condition is applied to the second row in t1 (using what is already inserted in t2), etc. - and you don't understand why there is any attempt to insert ALL the rows from t1 into t2. Why doesn't the third row fail the WHERE clause?
Good question! The reason is that operations are done on a SET basis. The WHERE condition uses table t2 AS IT WAS before the INSERT operation began. So for ALL rows, the WHERE clause compares to an empty table t2.
How to fix this... Decide which id you want to add when there are duplicate names. For example, one way to get the result you said you wanted is to select MIN(id) for each name. Moreover, you still want to check if the name exists in t2 already (since you may do this again in the future, when t2 is already partially populated).
insert into t2 ( id, name )
select min(id), name
from t1
where name not in (select name from t2)
group by name
;
You can try it bother....!
Insert into tb2(Field1, Field2)
SELECT Field1, Field2
FROM tb1
WHERE NOT EXISTS (SELECT Field1 FROM tb1) ;
This is how I understood the question:
SQL> create table table2
2 (id number,
3 name varchar2(2),
4 tag number,
5 constraint pk_t2 primary key (id, name)
6 );
Table created.
SQL>
SQL> insert into table2 (id, name, tag)
2 with test (id, name, tag) as
3 (select 1, 'N1', 2.1 from dual union
4 select 2, 'N2', 3.5 from dual union
5 select 3, 'N1', 3.5 from dual union
6 select 4, 'N3', 8.1 from dual
7 )
8 select min(id), name, max(tag)
9 from test
10 group by name;
3 rows created.
SQL>
SQL> select * from table2 order by id;
ID NA TAG
---------- -- ----------
1 N1 3,5
2 N2 3,5
4 N3 8,1
SQL>
When we need to unique any two or more column we have to create unique index.
Run this query
ALTER TABLE TABLE2 ADD UNIQUE unique_index( id, name);
and then
INSERT INTO TABLE2 (id,name,tag) VALUES(1, "N1", 3.5 )
ON DUPLICATE KEY UPDATE tag=3.5
this will also help to update new tag
Try to check if the id and name from Table1 is doesn't exist in Table2, if then insert.
If the unique constraint on TABLE2 is a composite key then run this:
INSERT INTO TABLE2 (ID, NAME)
SELECT A.ID, A.NAME
FROM TABLE1 A
WHERE NOT EXISTS (SELECT NULL FROM TABLE2 B WHERE A.ID=B.ID AND A.NAME=B.NAME);
If there are two unique constraints; one on the id, and the other on the name then run this instead:
INSERT INTO TABLE2 (ID, NAME)
SELECT A.ID, A.NAME
FROM TABLE1 A
WHERE NOT EXISTS (SELECT NULL FROM TABLE2 B WHERE A.ID=B.ID OR A.NAME=B.NAME);
ORACLE, in case you need to get values from 2 different tables.
below example,i use an increment case.
INSERT INTO TABLE1
(INDEX, REMARKS, NAME, AGE)
(SELECT (SELECT colescs(MAX(INDEX),0) FROM TABLE1)+1,
'any remarks',
t2.NAME, t2,age from TABLE2 t2 where t2.name = 'apple')
explanation
match below numbers (1)-(1), (2)-(2) ...
INSERT INTO TABLE1
(INDEX, //index increment (1)
REMARKS, //hard code (2)
NAME, //from table2 (3)
AGE) //from table2 (4)
(SELECT // this part is to get values from another table
(SELECT colescs(MAX(INDEX),0) FROM TABLE1)+1, //increment (1)
'any remarks', //hard code value (2)
t2.NAME, //from table2 (3)
t2,age //from table2 (4)
from TABLE2 t2 where t2.name = 'apple') //condition for table2
i have 2 tables .
The columns start with attributes are change based on department. the description of attributes are here
My requirement is to get the values of each attributes with its primary key based on the department as table bellow.
Honestly i am stuck on this problem in my program. I have no permission to change the tables and there is no common unique key column.i would appreciate if anyone could provide me a suggestion.
with a as (
select a.*, row_number() over (partition by department order by attributeID) rn
from attributes a),
e as (
select employeeId, department, attribute1, 1 rn from employees union all
select employeeId, department, attribute2, 2 rn from employees union all
select employeeId, department, attribute3, 3 rn from employees
)
select e.employeeId, a.attributeid, e.department, a.attribute, a.meaning,
e.attribute1 as value
from e join a on a.department=e.department and a.rn=e.rn
order by e.employeeId, a.attributeid
Test data and output:
create table employees (employeeID number(3), name varchar2(10), department varchar2(5), age number(3), attribute1 varchar2(10), attribute2 varchar2(10), attribute3 varchar2(10));
insert into employees values (1, 'john', 'IT', 22, 'attr1val1', 'attr2val2', null);
insert into employees values (2, 'jane', 'HR', 32, 'attr1val3', 'attr2val4', 'attr3val5');
insert into employees values (3, 'joe', 'HR', 23, 'attr1val6', 'attr2val7', 'attr3val8');
insert into employees values (4, 'jack', 'IT', 45, 'attr1val9', 'attr2val10', null);
create table attributes (attributeID number(3), department varchar2(10), attribute varchar2(10), meaning varchar2(10));
insert into attributes values (1, 'IT', 'attribute1', 'laptoptype');
insert into attributes values (2, 'IT', 'attribute2', 'networkloc');
insert into attributes values (3, 'HR', 'attribute1', 'location');
insert into attributes values (4, 'HR', 'attribute2', 'position');
insert into attributes values (5, 'HR', 'attribute3', 'allocation');
EMPLOYEEID ATTRIBUTEID DEPARTMENT ATTRIBUTE MEANING VALUE
---------- ----------- ---------- ---------- ---------- ----------
1 1 IT attribute1 laptoptype attr1val1
1 2 IT attribute2 networkloc attr2val2
2 3 HR attribute1 location attr1val3
2 4 HR attribute2 position attr2val4
2 5 HR attribute3 allocation attr3val5
3 3 HR attribute1 location attr1val6
3 4 HR attribute2 position attr2val7
3 5 HR attribute3 allocation attr3val8
4 1 IT attribute1 laptoptype attr1val9
4 2 IT attribute2 networkloc attr2val10
Edit: Explanation
In answer I used with
clause just to divide solution into readable steps. You can move them into from clause of main query if it is
more comfortable for you. Anyway: subquery a reads data from table attributes and adds number for rows,
so for each department they are allways numbered from 1. I used row_number() for that. Subquery e unions (all) required attributes and numbers
them accordingly. Numbers generated in both subqueries are then used in main join: a.department=e.department and a.rn=e.rn.
Alternative 1 - if you are using Oracle 11g you could use the unpivot. See what is generated by subquery, and how it is joined with attributes table:
with e as (
select employeeId, name, department, attribute, value from employees
unpivot (value for attribute in ("ATTRIBUTE1", "ATTRIBUTE2", "ATTRIBUTE3"))
)
select e.employeeId, a.attributeid, e.department, a.attribute,
a.meaning, e.value
from e join attributes a on a.department=e.department
and lower(a.attribute)=lower(e.attribute)
order by e.employeeId, a.attributeid;
Alternative 2 - with hierarchical subquery generator (subquery r), realised by connect by which simple creates numbers from 1, 2, 3 which are next joined with employees and proper attribute
is attached as value in case clause. Rest is made in similiar way like in original answer.
with a as (
select a.*, row_number() over (partition by department order by attributeID) rn
from attributes a),
r as (select level rn from dual connect by level<=3),
e as (
select employeeId, department, rn,
case when r.rn = 1 then attribute1
when r.rn = 2 then attribute2
when r.rn = 3 then attribute3
end value
from employees cross join r
)
select e.employeeId, a.attributeid, e.department, a.attribute,
a.meaning, e.value
from e join a on a.department=e.department and a.rn=e.rn
order by e.employeeId, a.attributeid
All three versions gave me the same output. I also tested first option on similiar table with 100k rows and get output in few seconds (for 5 attributes). Please test all solutions and try to understand them. If you can use unpivot version I would prefer this.
Sorry for delayed explanation and any language mistakes.
The WITH clause was added with Oracle 9.2 and should do the trick. For the other attributes just add more sub queries where the filter is att.attribute = 'attribute2' or 'Attribute3'...
WITH e AS
(SELECT emp.employee_ID, emp.department, emp.attribute1
FROM employee emp),
a AS (SELECT att.attribute_id, att.attribute, att.meaning
FROM attribute_TYPE att
WHERE att.attribute = 'attribute1')a
SELECT e.employeeid, att.attributeid, e.department, a.attribute,
a.meaning e.attribute1
FROM e JOIN a ON e.department = a.department
I am trying to join two tables together but the key in one table is formated like 'xxxxxx' and the key I am trying to join together in the second table is formated like '2222xxxxxx'. Is there a way I can either split the second column into two different columns to make the join, or join on only the last 6 numbers of column 2?
Notes: values are numeric. the '2222' is always the same 4 numbers.
Try this way:
select *
from table1 a
INNER JOIN table2 b
on a.fieldname = substr(b.fieldname, -6)
Here is the documentation for the SUBSTR Function in Oracle.
Know that this is a very bad design for your second table you should consider in separating this values in different columns.
EDIT
This comment from #Boneist "if there were 7 numbers after the first 4, not just 6?"
To fix this you should use: substr(b.fieldname, 5)
To separate that column on a select statement either you create a new column and update it values with the given substr or just add it in the select command.
On the select command:
select fielda, fieldb,
substr(b.fieldname, 1, 4) firstPartOfField,
substr(b.fieldname, 5) secondPartOfField
from tableb
To create another column it would be
alter table tableb add column newField number(6);
update tableb
set oldField = substr(b.fieldname,1,4),
newField = substr(b.fieldname,5);
I would suggest a slightly different approach:
If your column has varchar/char data type:
drop table tab1;
drop table tab2;
create table tab1(col char(30));
create table tab2(col char(30));
insert into tab1
select lpad(to_char(level), 6, '0') as val
from dual connect by level <=100 order by level;
insert into tab2
select '2222' || lpad(to_char(level), 6, '0') as val
from dual connect by level <=100 order by level;
create unique index ux_tab1 on tab1(col);
create unique index ux_tab2 on tab2(col);
select tab1.col, tab2.col
from tab1
join tab2
on '2222' || tab1.col = tab2.col;
-- check execution plan
explain plan for
select tab1.col, tab2.col
from tab1
join tab2
on '2222' || tab1.col = tab2.col;
select * from table(dbms_xplan.display);
If your column has number data type:
drop table tab1;
drop table tab2;
create table tab1(col number);
create table tab2(col number);
insert into tab1
select 100000 + level as val
from dual connect by level <=100 order by level;
insert into tab2
select 2222100000 + level as val
from dual connect by level <=100 order by level;
create unique index ux_tab1 on tab1(col);
create unique index ux_tab2 on tab2(col);
select tab1.col, tab2.col
from tab1
join tab2
on 2222000000 + tab1.col = tab2.col;
-- check execution plan
explain plan for
select tab1.col, tab2.col
from tab1
join tab2
on 2222000000 + tab1.col = tab2.col;
select * from table(dbms_xplan.display);
Using this approach Oracle will be able to use indexes for joining !
I know that the union operator is used to (for example) return all rows from two tables after eliminating duplicates. Example:
SELECT a_id
FROM a
UNION
SELECT b_id
FROM b;
The result of listing of all elements in A and B eliminating duplicates is {1,2,3,4,5,6,7,8}.
If you joined A and B you would get only {4,5}. You would have to perform a full outer join to get the full list of 1-8. My question is if I wanted to use the union operator to display from a table called employees, the employee_id and job_id ( employee id being a number data type, and job_id being a VARCHAR2 data type) How would I go about doing this?
Would it be something like this: This does not run in oracle obviously,
SELECT employee_id
UNION
SELECT job_id
FROM employees;
If you really wanted to union together all the EMPLOYEE_IDs followed by all the JOB_IDs you'd use
SELECT TO_CHAR(EMPLOYEE_ID) FROM EMPLOYEES
UNION ALL
SELECT JOB_ID FROM EMPLOYEES
If you had rows with EMPLOYEE_IDs of 1, 2, and 3, and those same rows had JOB_IDs of 1, 11, and 111 you'd get a result set of six rows with a single column which would have values of
1
2
3
1
11
111
By using UNION ALL Oracle will allow the duplicates to pass through.
Share and enjoy.