I could not find a solution for this yet. I want to insert multiple rows with 2 or more different hardcoded values, but also with data that I get from another table.
Example: I want to add 2 items into a table for a user that has the ID = '0' in another table without running 2 queries.
This is what I've done so far:
INSERT INTO
DB.dbo.Table WITH(ROWLOCK, XLOCK) (
col1,
col2,
col3,
col4
)
SELECT
DISTINCT customer_id,
hardcoded_value1,
constant1,
constant2
FROM
DB.dbo.Other_Table
WHERE
ID = '0';
You could cross join your select query with a table value constructor that holds several records with harcoded values. This will generate as many rows as provided in the table value constructor for each row return by the query.
INSERT INTO
DB.dbo.Table WITH(ROWLOCK, XLOCK) (
col1,
col2,
col3,
col4
)
SELECT
DISTINCT t.customer_id,
x.hardcoded_value,
t.constant1,
t.onstant2
FROM DB.dbo.Other_Table t
CROSS JOIN (VALUES ('harcoded 1'), ('harcoded 2')) as x(hardcoded_value)
WHERE t.ID = '0';
I can't tell from your question what the basis is for the different values. You may be able to use a CASE statement to insert different hardcoded values based on some criteria:
INSERT INTO
DB.dbo.Table WITH(ROWLOCK, XLOCK) (
col1,
col2,
col3,
col4
)
SELECT
DISTINCT customer_id,
CASE WHEN Condition1 THEN hardcoded_value1
WHEN Condition2 THEN hardcoded_value2
...
END,
constant1,
constant2
FROM
DB.dbo.Other_Table
WHERE
ID = '0';
Related
I have the same table structure called "table1" under two different schemas "schema1" and "schema2". "table1" contains columns "col1, col2, col3". Initialy I want see whether there are records having the same entries of col1 and col2 in the table schema1.table1 and schema2.table1. But I had mistyped schema2.table1 as schema1.table1. And now I am confused by the query result.
SELECT COUNT(*) FROM schema1.table1 AS s1t, schema1.table1 AS s2t
WHERE s1t.col1 = s2t.col1 AND s1t.col2 = s2t.col2;
I got
count
-------
530
(1 row)
However, SELECT COUNT(*) FROM schema1.table1; shows that there are 17815 rows.
Why would the first query show there are only 530 satisfied records? Shouldn't it be 17815 as well?
You can try to use FULL OUTER JOIN to see even mismatched rows, including null values for columns(col1 and 2). This way, at least(more than or equal to) 17815 rows return
SELECT COUNT(*)
FROM schema1.table1 AS s1t
FULL OUTER JOIN schema1.table1 AS s2t
ON s1t.col1 = s2t.col1 AND s1t.col2 = s2t.col2
In your case, only matched rows return for those columns (col1 and 2).
You are joining the table to itself. That is really strange.
In any case, your join is going to filter out any rows where col1 or col2 are NULL.
In addition, the self-join might multiply the number of rows if there are duplicates (with respect to the two columns) in the table.
It is really unclear why you would be doing this, but the above explains the results you are seeing.
If you want to compare the results in the two schemas allowing for duplicates and missing values, I recommend union all/group by:
select col1, col2, sum(cnt1) as cnt1, sum(cnt2) as cnt2
from ((select col1, col2, count(*) as cnt1, 0 as cnt2
from schema1.table1
group by col1, col2
) union all
(select col1, col2, 0 as cnt1, count(*) as cnt2
from schema2.table1
group by col1, col2
)
) t12
group by col1, col2
having sum(cnt1) <> sum(cnt2);
This returns pairs where the counts are not the same in the two tables. It even works for NULL values. If you ran this on the same table, no rows would be returned.
I have getting same records multiple times with one column value changed using union like this.
Select col1, col2, 'A' as col3
Union
Select col1, col2, 'B' as col3
Union
Select col1, col2, 'C' as col3
I want to know if there is any way to do this in single query instead of writing 3 queries. Can someone please help?
I simple CROSS JOIN with the specified VALUES should do the trick
Select Col1,Col2,Col3
From YourTable A
Cross Join (Values ('A'),('B'),('C') ) B (Col3)
SELECT d.name, x.field1
FROM sys.databases d
, (VALUES('A'), ('B'), ('C')) AS x(field1)
You should look up the cross join syntax but this is an example off how to do it.
What is the advantage of inserting into a select of a table over simply inserting into the table?
eg
insert into
( select COL1
, COL2
from Table1
where 1=2 <= this and above is the focus of the question.
) select COL3, COL4 from Table2 ;
It seems to do the same thing as:
insert into Table1
( COL1, COL2 )
select COL3, COL4 from Table2 ;
This is the first time I've seen this; our Sr Dev says there is some advantage but he can't remember what it is.
It may make sense in a way if one was inserting a "select *..." from a table with lots of columns, and we want to be lazy, but... we're not. We're enumerating each column in the table.
Database is Oracle 11gR2, but this query was written probably in 10g or before.
we want to be lazy
No, we use insert into table(col1, col2) select col2, col2 from ... when there is a lot of records (for example 1M) and we don't want to create a the values section for each. Let's imagine how much time it takes if you write
insert into table (col1, col2)
values (select col1, col2 from (select col1, col2, rownum rn from ...) where rn = 1);
insert into table (col1, col2)
values (select col1, col2 from (select col1, col2, rownum rn from ...) where rn = 2);
...
insert into table (col1, col2)
values (select col1, col2 from (select col1, col2, rownum rn from ...) where rn = 1000000);
insert select is faster way for copying data from one table(several tables) to an another table.
In a nutshell. It's a lot easier. Especially when you have a massive query that you dont wanna rebuild,or if you have a crapton of objects, or values you are inserting.
Without WITH CHECK OPTION specified, I don't know of any purpose for this syntax. If you specify WITH CHECK OPTION, you can effectively implement an ad-hoc check constraint within your insert statement.
insert into
( select COL1
, COL2
from Table1
where 1=2 WITH CHECK OPTION
) select COL3, COL4 from Table2 ;
The above will never insert a record, because 1 will never equal 2.
The statement below will insert a record as long as COL3 is less than 100, otherwise an exception is raised.
insert into
( select COL1
, COL2
from Table1
where COL1 < 100 WITH CHECK OPTION
) select COL3, COL4 from Table2 ;
Sorry, I asked this question just before and got some good answers but then I realised I made a mistake with the query in question, if I change the question in the original post that could make the answers invalid so I'm posting again with the right query this time, please forgive me, I hope this is acceptable.
DECLARE #Temp TABLE
(MeasureDate, col1, col2, type)
INSERT INTO #Temp
SELECT MeasureDate, col1, col2, 1
FROM Table1
WHERE Col3 = 1
INSERT INTO #Temp
SELECT MeasureDate, col1, col2, 3
FROM Table1
WHERE Col3 = 1
AND Col4 = 7000
SELECT SUM(col1) / SUM(col2) AS Percentage, MeasureDate, Type
FROM #Temp
GROUP BY MeasureDate, Type
I do two inserts into the temp table, 2nd insert with an extra WHERE but same columns same table, but different type, then I do SUM(col1) / SUM(col2) on the temp table to return the result I need per MeasureDate and type. Is there a way to merge all these inserts and selects into one statement so I don't use a temp table and do a single select from Table1? Or even if I still need the temp table, merge the selects into one select instead of two separate selects? Stored procedure works fine as it is, just looking for a way to shorten it.
Thanks.
Sure can. I might start with combining the two queries from your inserts using UNION ALL (this variation of UNION will not remove duplicates), wrapped up in a CTE from which you can perform your final query:
WITH MeasureData(MeasureDate, col1, col2, type) AS (
SELECT MeasureDate, col1, col2, 1
FROM Table1
WHERE Col3 = 1
UNION ALL
SELECT MeasureDate, col1, col2, 3
FROM Table1
WHERE Col3 = 1
AND Col4 = 7000
)
SELECT SUM(col1) / SUM(col2) AS Percentage, MeasureDate, Type
FROM MeasureData
GROUP BY MeasureDate, Type
That's it, no more table variable or insert statements.
No real need for a UNION, you can handle this with a CASE statement:
SELECT SUM(col1) / SUM(col2) AS Percentage, MeasureDate, Type
FROM (
SELECT MeasureDate, col1, col2, case when Col4 = 7000 then 3 else 1 end type
FROM Table1
WHERE Col3 = 1
) t
GROUP BY MeasureDate, Type
Edit, as Gordon correctly points out, for Type = 1, this query wouldn't produce the same results. Here's a variation on Gordon's good answer that might be easier to visually understand using a CROSS JOIN and IF logic:
SELECT T1.MeasureDate,
T.Type,
SUM(IF(T.Type=1,Col1,IF(T.Type=3 AND T1.Col4=7000,T1.Col1,0))) /
SUM(IF(T.Type=1,Col2,IF(T.Type=3 AND T1.Col4=7000,T1.Col2,0))) AS Percentage
FROM Table1 T1
CROSS JOIN (SELECT 1 Type UNION SELECT 3) T
WHERE T1.Col3 = 1
GROUP BY T1.MeasureDate, T.Type
Condensed SQL Fiddle
Your method is double counting cases where col3 = 1 and col4 = 7000. Here is a method that takes this into account, without union on the overall table:
select t.type, SUM(t1.col1) / SUM(t1.col2) AS Percentage, t1.MeasureDate, t.Type
from table1 t1 join
(select 1 as type union all
select 3 as type
) t
on t.type = 1 or t1.col4 = 7000
where t1.col3 = 1
group by measuredate, type;
I have PostgreSQL 9 database that uses auto-incrementing integers as primary keys. I want to duplicate some of the rows in a table (based on some filter criteria), while changing one or two values, i.e. copy all column values, except for the ID (which is auto-generated) and possibly another column.
However, I also want to get the mapping from old to new IDs. Is there a better way to do it then just querying for the rows to copy first and then inserting new rows one at a time?
Essentially I want to do something like this:
INSERT INTO my_table (col1, col2, col3)
SELECT col1, 'new col2 value', col3
FROM my_table old
WHERE old.some_criteria = 'something'
RETURNING old.id, id;
However, this fails with ERROR: missing FROM-clause entry for table "old" and I can see why: Postgres must be doing the SELECT first and then inserting it and the RETURNING clauses only has access to the newly inserted row.
RETURNING can only refer to the columns in the final, inserted row. You cannot refer to the "OLD" id this way unless there is a column in the table to hold both it and the new id.
Try running this which should work and will show all the possible values that you can get via RETURNING:
INSERT INTO my_table (col1, col2, col3)
SELECT col1, 'new col2 value', col3
FROM my_table AS old
WHERE old.some_criteria = 'something'
RETURNING *;
It won't get you the behavior you want, but should illustrate better how RETURNING is designed to work.
This can be done with the help of data-modifiying CTEs (Postgres 9.1+):
WITH sel AS (
SELECT id, col1, col3
, row_number() OVER (ORDER BY id) AS rn -- order any way you like
FROM my_table
WHERE some_criteria = 'something'
ORDER BY id -- match order or row_number()
)
, ins AS (
INSERT INTO my_table (col1, col2, col3)
SELECT col1, 'new col2 value', col3
FROM sel
ORDER BY id -- redundant to be sure
RETURNING id
)
SELECT s.id AS old_id, i.id AS new_id
FROM (SELECT id, row_number() OVER (ORDER BY id) AS rn FROM ins) i
JOIN sel s USING (rn);
SQL Fiddle demonstration.
This relies on the undocumented implementation detail that rows from a SELECT are inserted in the order provided (and returned in the order provided). It works in all current versions of Postgres and is not going to break. Related:
Does Postgres preserve insertion order of records?
Window functions are not allowed in the RETURNING clause, so I apply row_number() in another subquery.
More explanation in this related later answer:
INSERT INTO ... FROM SELECT ... RETURNING id mappings
Good! I test this code, but I change
this (FROM my_table AS old) in (FROM my_table) and
this (WHERE old.some_criteria = 'something') in (WHERE some_criteria = 'something')
This is the final code that I use
INSERT INTO my_table (col1, col2, col3)
SELECT col1, 'new col2 value', col3
FROM my_table AS old
WHERE some_criteria = 'something'
RETURNING *;
Thanks!
DROP TABLE IF EXISTS tmptable;
CREATE TEMPORARY TABLE tmptable as SELECT * FROM products WHERE id = 100;
UPDATE tmptable SET id = sbq.id from (select max(id)+1 as id from products) as sbq;
INSERT INTO products (SELECT * FROM tmptable);
DROP TABLE IF EXISTS tmptable;
add another update before the insert to modify another field
UPDATE tmptable SET another = 'data';
'old' is a reserved word, used by the rule rewrite system.
[ I presume this query fragment is not part of a rule; in that case you would have phrased the question differently ]