I am using Postgresql db. I have data in two tables. Table A has 10 records and Table B 5 records.
I would like to copy Table A data to Table B but only copy the new entries (5 records) and ignore the duplicates/already existing data
I would like to copy data from Table A to Table B where Table B will have 10 records (5 old records + 5 new records from Table A)
Can you please help me as to how can this be done?
Assuming id is your primary key, and table structures are identical(both table has common columns as number of columns and data type respectively), use not exists :
insert into TableB
select *
from TableA a
where not exists ( select 0 from TableB b where b.id = a.id )
If you are looking to copy rows unique to A that are not in B then you can use INSERT...SELECT. The SELECT statement should use the union operator EXCEPT:
INSERT INTO B (column)
SELECT column FROM A
EXCEPT
SELECT column FROM B;
EXCEPT (https://www.postgresql.org/docs/current/queries-union.html) compares the two result sets and will return the distinct rows present in result A but not in B, then supply these values to INSERT. For this to work both the columns and respective datatypes must match in both SELECT queries and your INSERT.
INSERT INTO Table_A
SELECT *
FROM Table_B
ON CONFLICT DO NOTHING
Here, the conflict will be taken based on your primary key.
Related
Due to a certain requirement, I need to create two temp tables in Stored Procedure, after processing some data into them, I need to combine the two temp tables to show as one result set and generate into excel. So I'm thinking to use UNION when I want to show the final result set.
The issue is, the first temp table (Table A) is fixed to 20 columns, and the second temp table has 50 columns (Table B). My plan is, before processing data for Table A, I want to add 30 nullable columns and insert data for first 20 columns, and the rest is all NULL
After I process the data for Table B, I use UNION to combine Table A & B so that they will show as one result set.
What I can think of right now is to hard code some columns that are destined to have null values when I declare the temp table:
Declare #tmpTableA table (
....
ProcessDate datetime,
Mode int,
Col21 varchar(10)
Col22 varchar(10)
....
Col50 varchar(50)
)
When I insert data into Table A, I have to manually add null from Col21 onwards
Insert into(.... Col21, Col22, Col23....)
Values (.... NULL, NULL, NULL....)
After I complete processing data for Table A & B, I use UNION to merge Table A and B
Select *....Col49,Col50 From Table A
Union
Select *....CompleteDate,ContactPerson From Table B
Instead of hard-coding Col21 to Col50 into Table A, is there any elegant way to achieve that like using while loop to dynamically add N number of columns into Table A?
EDIT:
According to latest requirement, Table B has not only 50 columns but 100 columns! I really need a way to dynamically loop those columns rather than hard-coding for over 80 columns
I think you can just do
select * into #tableA from #tableB where 1=2
with this both tables will have same columns
You don't need to add columns to table A, just add 30 NULLs to select from Table A.
Select *,NULL,...,NULL,NULL From Table A
Union
Select * From Table B
You could add aliases to make the result a bit cleaner
Select *,...,NULL CompleteDate, NULL ContactPerson From Table A
Union
Select * From Table B
I have a table with, let's say, 100 records. The table has two columns. The first column (A) has unique values. The second column (B) has NULL values
For 4 elements from column A I'd like to associate some earlier defined values, and they are unique as well.
I don't care about which value from column B will be associated with the value from column A. I'd like to associate 4 unique values with another 4 unique values. Basically, like I'd cut and paste a block of values from one column to another in excel.
How can I do it without using cursors?
I'd like to use one Update statement for ALL rows instead one Update statement for EVERY row as I do now.
Try this:
UPDATE t
SET ColumnB = BValue
FROM Table t
INNER JOIN
(
SELECT 1 AValue, 'Mouse' BValue UNION
SELECT 2, 'Cat' UNION
SELECT 3, 'Dog' UNION
SELECT 4, 'Wolf'
) PreDefined ON(t.ColumnA = PreDefined.AValue)
Use any number you want in the 'PreDefined' table, as long as they are unique and within the range of values in columnA of your original table.
If you are only trying to fill a table for testing purposes, I guess you could:
A) Use the value from Column A itself (as it is already unique).
B) If they are to be different, use some function on the column A's value to obtain a column B value (something simple, like (ColumnA * 10), and this would give youA)
C) Create a temp table with a "dictionary" setting a B value for each possible A value, and then update the rows desired on your table looking up from values on this dictionary table.
Anyway, if you explain a little further your purpose it will be easier to try suggesting you a solution.
if your animal data is already in a database table, then you can use a single update statement like this:
update target_table t4
set columnb = (
select animal_name
from (select columna, animal_name
from (select rownum rowNumber, animal_name from animal_table) t1
join (select rownum rowNumber, columna from target_table t1 where columnb is null) t2
on t1.rowNumber = t2.rowNumber
) t3
where t4.columna = t3.columna
)
;
this works by selecting a sequence number and animal name from the source table, then selecting a sequence number and columna value from your target table. by joining those records on the sequence number you guarantee you get exactly 1 animal name for each columna value. you can then join those columna-to-animal records to your target table to do an update of columnb.
for more background on updating one table from values in another, you might consider the solutions presented here: Update rows in one table with data from another table based on one column in each being equal. the only difference is that in your example, you do not have any column that matches between your target table and your animal names table, so you need to use the rownum to create an arbitrary 1-to-1 matching of records.
if your unique options are in a text file or spreadsheet, then you can format them into a fixed-width space-padded string and pick the one you want using the rownum index like so:
update table_name
set columnb = trim(substr('mouse cat dog wolf ', rownum*6-6, 6))
where columnb is null;
I have two table one is having all field VARCHAR2 but other having different type for different data.
For Example :
Table One
==========================
Col 1 VARCHAR2 UNIQUE KEY
Col 2 VARCHAR2
Col 3 VARCHAR2
===========================
Table Two
==========================
Col One VARCHAR2 UNIQUE KEY
Col Two TIMESTAMP
Col Three NUMBER
==========================
we are having one mapping table. it denotes which column of Table One has to compare with which column of Table Two.
For Example
Mapping Table
==============================
Table One Table Two
==============================
Col 1 Col One
Col 2 Col Three
Col 3 Col Two
==============================
Now with the help of UNIQUE KEY of TABLE ONE we have to find same row in TABLE TWO and compare rows column by column and get changes in data.
Currently we are using java program for comparing data row by row and column by column and getting changes between data in rows with same UNIQUE KEY. it is working fine but taking too much time as we are having 100000 records in DB.
Now my question is : is there any way i can compare data at SQL level and get changes in data?
You can do it 'manually' with a query like this: It's a lot of work, but there are only three different types of checks you need to do, so it's not very complex:
select
*
from
Table1 t1
full outer join Table2 t2 on t2.ID = t1.ID
where
-- Check ID, either record does not exist in either table.
t1.ID is null or
t2.ID = null or
-- Not nullable field can be easily compared.
t1.NotNullableField1 <> t2.NotNUllableField1 or
-- Nullable field is slightly more work.
t1.NullableField1 <> t2.NullableField1 or
(t1.NullableField1 is null and t2.NullableField1 is not null) or
(t1.NullableField1 is not null and t2.NullableField1 is null)
Another solution is to use MINUS, which is a bit like UNION, only it returns a dataset minus the records in a second dataset:
select * from Table1 t1
MINUS
select * from Table2 t2
This works only one way (which might be fine for your purpose), but you can also combine it with UNION to make it bidirectional.
select
*
from
( select * from Table1
MINUS
select * from Table2)
UNION ALL
( select * from Table2
MINUS
select * from Table1)
The output of both solutions is a bit different.
In the FULL OUTER JOIN query, the IDs will be joined and the values of the matching rows will be displayed next to each other as a single row.
In the MINUS query, the result will be presented as a single dataset. If a record does not exist in either one table, it will be displayed. If a record (ID) exists in both tables, but other fields are different, you will get both rows. So it's a bit harder to compare them.
See: http://www.techonthenet.com/oracle/minus.php
all with the same column headings and I would like to create one singular table from all three.
I'd also, if it is at all possible, like to create a trigger so that when one of these three source tables is edited, the change is copied into the new combined table.
I would normally do this as a view, however due to constraints on the STSrid, I need to create a table, not a view.
Edit* Right, this is a bit ridiculous but anyhow.
I HAVE THREE TABLES
THERE ARE NO DUPLICATES IN ANY OF THE THREE TABLES
I WANT TO COMBINE THE THREE TABLES INTO ONE TABLE
CAN SOMEONE HELP PROVIDE THE SAMPLE SQL CODE TO DO THIS
ALSO IS IT POSSIBLE TO CREATE TRIGGERS SO THAT WHEN ONE OF THE THREE TABLES IS EDITED THE CHANGE IS PASSED TO THE COMBINED TABLE
I CAN NOT CREATE A VIEW DUE TO THE FACT THAT THE COMBINED TABLE NEEDS TO HAVE A DIFFERENT STSrid TO THE SOURCE TABLES, CREATING A VIEW DOES NOT ALLOW ME TO DO THIS, NOR DOES AN INDEXED VIEW.
Edit* I Have Table A,Table B and Table C all with columns ORN, Geometry and APP_NUMBER. All the information is different so
Table A (I'm not going to give an example geometry column)
ORN ID
123 14/0045/F
124 12/0002/X
Table B (I'm not going to give an example geometry column)
ORN ID
256 05/0005/D
989 12/0012/X
Table C (I'm not going to give an example geometry column)
ORN ID
043 13/0045/D
222 11/0002/A
I want one complete table of all info
Table D
ORN ID
123 14/0045/F
124 12/0002/X
256 05/0005/D
989 12/0012/X
043 13/0045/D
222 11/0002/A
Any help would be greatly appreciated.
Thanks
If the creation of the table is a one time thing you can use a select into combined with a union like this:
select * into TableD from
(
select * from TableA
union all
select * from TableB
union all
select * from TableC
) UnionedTables
As for the trigger, it should be easy to set up a after insert trigger like this:
CREATE TRIGGER insert_trigger
ON TableA
AFTER INSERT AS
insert TableD (columns...) select (columns...) from inserted
Obviously you will have to change the columns... to match your structure.
I haven't checked the syntax though so it might not be prefect and it could need some adjustment, but it should give you an idea I hope.
If IDs are not duplicated it ill be easy to achieve it, in another case you can must add a OriginatedFrom column. You also can create a lot of instead off triggers (not only for insert but for delete and update) but that a lazy excuse for not refactoring the app.
Also you must pay attention for any reference for the data, since its a RELATIONAL model is likely to other tables are related to the table you are about to drop.
This is the code for create the table D
drop table D;
Select * into D from (select * from A Union all select* from B Union all select * from C);
Its rather simple Just Create Table_D First
CREATE TABLE_D
(
ORN INT,
ID VARCHAR(20),
Column3 Datatype
)
GO
Use INSERT statement to insert records into this table SELECTing and using UNION ALL operator from other three table.
INSERT INTO TABLE_D (ORN , ID, Column3)
SELECT ORN , ID, Column3
FROM Table_A
UNION ALL
SELECT ORN , ID, Column3
FROM Table_B
UNION ALL
SELECT ORN , ID, Column3
FROM Table_C
Trigger
You will need to create this trigger on all of the tables.
CREATE TRIGGER tr_Insert_Table_A
ON TABLE_A
FOR INSERT
AS
BEGIN
SET NOCOUNT ON;
INSERT INTO TABLE_D (ORN , ID, Column3)
SELECT i.ORN , i.ID, i.Column3
FROM Inserted i LEFT JOIN TABLE_D D
ON i.ORN = D.ORN
WHERE D.ORN IS NULL
END
Read here to learn more about SQL Server Triggers
This is a specific problem .
I have an excel sheet containing data. Similar data is present in a relational database table. Some rows may be absent or some additional rows may be present. The goal is to verify the data in the excel sheet with the data in the table.
I have the following query
Select e_no, start_dt,end_dt
From MY_TABLE
Where e_no In
(20231, 457)
In this case, e_no 457 is not present in the database (and hence not returned). But I want my query to return a row even if it not present (457 , null , null). How do I do that ?
For Sql-Server: Use a temporary table or table type variable and left join MY_TABLE with it
Sql-Server fiddle demo
Declare #Temp Table (e_no int)
Insert into #Temp
Values (20231), (457)
Select t.e_no, m.start_dt, m.end_dt
From #temp t left join MY_TABLE m on t.e_no = m.e_no
If your passing values are a csv list, then use a split function to get the values inserted to #Temp.
Why not simply populate a temporary table in the database from your spreadsheet and join against that? Any other solution is probably going to be both more work and more difficult to maintain.
You can also do it this way with a UNION
Select
e_no, start_dt ,end_dt
From MY_TABLE
Where e_no In (20231, 457)
UNION
Select 457, null, null