I have three tables table A , table B and table C. I need to populate C with the combination of A and B.
How can i populate table C with the results of the query below?
UPDATE dbo.C
SELECT TOP (200000) dbo.A.Id, dbo.B.Id
FROM [testDB].[dbo].A
CROSS JOIN [testDB].[dbo].B
You can use INSERT INTO . .SELECT if table already exists :
INSERT INTO dbo.c(aID, bID) -- Qualify correct column names
SELECT TOP (200000) dbo.A.Id, dbo.B.Id
FROM [testDB].[dbo].A CROSS JOIN
[testDB].[dbo].B
ORDER BY ???; -- Use ordering column to specify the sequence
If table C doesn't exists then use INTO :
SELECT TOP (200000) dbo.A.Id, dbo.B.Id INTO [testDB].[dbo].C
FROM [testDB].[dbo].A CROSS JOIN
[testDB].[dbo].B
ORDER BY ???; -- Use ordering column to specify the sequence
Related
We have a PostgreSQL database where I have two tables with column text[] datatype. When I use an inner join to get details I do not see it is matching with any row.
for e.g.
create table test{
names text[],
id
}
create table test_b{
names text[],
id
}
now when I run below query,
SELECT t.* from test t inner join test_b tt
where t.names=tt.names;
I don't see any results. I even tried normal query with
SELECT * FROM test where names='{/test/test}';
It also did not work.
Any suggestions?
I suspect that you want array overlap operator &&. Also, since you don't need to return anything from test_b, using exists with a correlated subquery is more relevant than a join:
select t.*
from test t
where exists (select 1 from test_b b where t.names && b.names)
I keep coming across this DELETE FROM FROM syntax in SQL Server, and having to remind myself what it does.
DELETE FROM tbl
FROM #tbl
INNER JOIN tbl ON fk = pk AND DATEDIFF(day, #tbl.date, tbl.Date) = 0
EDIT: To make most of the comments and suggested answers make sense, the original question had this query:
DELETE FROM tbl
FROM tbl2
As far as I understand, you would use a structure like this where you are restricting which rows to delete from the first table based on the results of the from query. But to do that you need to have a correlation between the two.
In your example there is no correlation, which will effectively be a type of cross join which means "for every row in tbl2, delete every row in tbl1". In other words it will delete every row in the first table.
Here is an example:
declare #t1 table(A int, B int)
insert #t1 values (15, 9)
,(30, 10)
,(60, 11)
,(70, 12)
,(80, 13)
,(90, 15)
declare #t2 table(A int, B int)
insert #t2 values (15, 9)
,(30, 10)
,(60, 11)
delete from #t1 from #t2
The result is an empty #t1.
On the other hand this would delete just the matching rows:
delete from #t1 from #t2 t2 join #t1 t1 on t1.A=t2.A
I haven't seen this anywhere before. The documentation of DELETE tells us:
FROM table_source Specifies an additional FROM clause. This
Transact-SQL extension to DELETE allows specifying data from
and deleting the corresponding rows from the table in
the first FROM clause.
This extension, specifying a join, can be used instead of a subquery
in the WHERE clause to identify rows to be removed.
Later in the same document we find
D. Using joins and subqueries to data in one table to delete rows in
another table The following examples show two ways to delete rows in
one table based on data in another table. In both examples, rows from
the SalesPersonQuotaHistory table in the AdventureWorks2012 database
are deleted based on the year-to-date sales stored in the SalesPerson
table. The first DELETE statement shows the ISO-compatible subquery
solution, and the second DELETE statement shows the Transact-SQL FROM
extension to join the two tables.
With these examples to demonstrate the difference
-- SQL-2003 Standard subquery
DELETE FROM Sales.SalesPersonQuotaHistory
WHERE BusinessEntityID IN
(SELECT BusinessEntityID
FROM Sales.SalesPerson
WHERE SalesYTD > 2500000.00);
-- Transact-SQL extension
DELETE FROM Sales.SalesPersonQuotaHistory
FROM Sales.SalesPersonQuotaHistory AS spqh
INNER JOIN Sales.SalesPerson AS sp
ON spqh.BusinessEntityID = sp.BusinessEntityID
WHERE sp.SalesYTD > 2500000.00;
The second FROM mentions the same table in this case. This is a weird way to get something similar to an updatable cte or a derived table
In the third sample in section D the documentation states clearly
-- No need to mention target table more than once.
DELETE spqh
FROM
Sales.SalesPersonQuotaHistory AS spqh
INNER JOIN Sales.SalesPerson AS sp
ON spqh.BusinessEntityID = sp.BusinessEntityID
WHERE sp.SalesYTD > 2500000.00;
So I get the impression, the sole reason for this was to use the real table's name as the DELETE's target instead of an alias.
I have two tables namely :- TDM & AccountMaster. Both are having three equal columns and I have to create a table retrieving all the rows from TDM-table joining the three columns,i.e. FD_BRANCH,FD_CUSTCODE & PRODUCTID.
while creating table through select into clause I get an error
Column names in each table must be unique. Column name 'FD_BRANCH' in table 'acty' is specified more than once.
Please find the following query from which I want to create a table which as per my requirement :-
SELECT * FROM (SELECT FD_BRANCH,FD_CUSTCODE,PRODUCTID FROM TDM
GROUP BY FD_BRANCH,FD_CUSTCODE,PRODUCTID) A full OUTER JOIN AccountMaster B
ON( A.FD_BRANCH=B.FD_BRANCH AND A.FD_CUSTCODE=B.FD_CUSTCODE AND
A.PRODUCTID=B.PRODUCTID)
Change your select to get only the fields you need from one of the 2 tables.
Select A.*
FROM (
or
Select B.FD_BRANCH,
B.FD_CUSTCODE,
B.PRODUCTID
FROM (
FULL OUTER JOIN combines the 2 sets of columns from both queries so you end up with at least 6 columns. Even though they're from different tables or aliases the columns names are the same.
I'm trying to update a column in one table (#TEMPTABLE) using data in another table (#PEOPLE) by using the REPLACE() function.
#TEMPTABLE has a column called "NameString' that is a long string with a user's name and ID.
#PEOPLE has a column for ID, and IDnumber.
UPDATE #TEMPTABLE
SET NAMEString = REPLACE(NAMEString, a.[ID], a.[IDNumber]) FROM #PEOPLE a
I'm trying to replace all the ID's in the NameString Column with the IDnumbers coming from #People table.
You need to give it a join criterion. For example:
update #TEMPTABLE
set NAMEString = replace(a.NAMEString, a.ID, b.IDNumber)
from #TEMPTABLE a
left join #PEOPLE b
on a.id = b.ID
Also, make sure to reference the right table when you use the IDNumber column - your original query doesn't actually use the table containing IDNumber at all, as far as I can tell from your description of your tables.
Note that my example assumes there's an ID field in #TempTable, or something else to join on - otherwise, you may need to extract it from the NameString column first.
I want to join 2 tables using an Inner Join on 2 columns, both are of (nvarchar, null) type. The 2 columns have the same data in them, but the join condition is failing. I think it is due to the spaces contained in the column values.
I have tried LTRIM, RTRIM also
My query:
select
T1.Name1, T2.Name2
from
Table1 T1
Inner Join
Table2 on T1.Name1 = T2.Name2
I have also tried like this:
on LTRIM(RTRIM(T1.Name1)) = LTRIM(RTRIM(T2.Name2))
My data:
Table1 Table2
------ ------
Name1(Column) Name2(Column)
----- ------
Employee Data Employee Data
Customer Data Customer Data
When I check My data in 2 tables with
select T1.Name1,len(T1.Name1)as Length1,Datalength(T1.Name1)as DataLenght1 from Table1 T1
select T2.Name2,len(T2.Name2)as Length2,Datalength(T2.Name2)as DataLenght2 from Table2 T2
The result is different Length and DataLength Values for the 2 tables,They are not same for 2 tables.
I can't change the original data in the 2 tables. How can I fix this issue.
Thank You
Joins do not have special rules for equality. The equality operator always works the same way. So if a = b then the join on a = b would work. Therefore, a <> b.
Check the contents of those fields. They will not be the same although you think they are:
select convert(varbinary(max), myCol) from T
Unicode has invisible characters (that only ever seem to cause trouble).
declare #t table (name varchar(20))
insert into #t(name)values ('Employee Data'),('Customer Data')
declare #tt table (name varchar(20))
insert into #tt(name)values ('EmployeeData'),('CustomerData')
select t.name,tt.name from #t t
INNER JOIN #tt tt
ON RTRIM(LTRIM(REPLACE(t.name,' ',''))) = RTRIM(LTRIM(REPLACE(tt.name,' ','')))
I would follow the following schema
Create a new table to store all the possible names
Add needed keys and indexes
Populate with existing names
Add columns to your existing tables to store the index of the name
Create relative foreign keys
Populate the new columns with correct indexes
Create procedure to perform an insert in new tables names only in case the value is not existing
Perform the join using the new indexes