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Querying data by joining two tables in two database on different servers
There are two tables in two different databases on different servers, I need to join them so as to make few queries. What options do I have? What should I do?
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Efficiently convert rows to columns in sql server
...Code, LastName, AccountNumber
from
(
select value, columnname
from yourtable
) d
pivot
(
max(value)
for columnname in (Firstname, Amount, PostalCode, LastName, AccountNumber)
) piv;
See Demo.
Pivot with unknown number of columnnames
If you have an unknown number of columnnames that you w...
“Insert if not exists” statement in SQLite
...te database. I am trying to insert values ( users_id , lessoninfo_id ) in table bookmarks , only if both do not exist before in a row.
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SQL Server dynamic PIVOT query?
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Dynamic SQL PIVOT:
create table temp
(
date datetime,
category varchar(3),
amount money
)
insert into temp values ('1/1/2012', 'ABC', 1000.00)
insert into temp values ('2/1/2012', 'DEF', 500.00)
insert into temp values ('2/1/2012', 'GHI',...
Delete duplicate records in SQL Server?
Consider a column named EmployeeName table Employee . The goal is to delete repeated records, based on the EmployeeName field.
...
How to sum a variable by group
...he syntax behind each alternative. For instance, if I have a larger source table and want to subselect just two dimensions plus summed metrics, can I adapt any of these methods? Hard to tell.
– Dodecaphone
Oct 28 '18 at 10:42
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How can I rename a database column in a Ruby on Rails migration?
...
rename_column :table, :old_column, :new_column
You'll probably want to create a separate migration to do this. (Rename FixColumnName as you will.):
script/generate migration FixColumnName
# creates db/migrate/xxxxxxxxxx_fix_column_name....
SQL Server - Return value after INSERT
... get a the key-value back after an INSERT-statement.
Example:
I've got a table with the attributes name and id. id is a generated value.
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SQL/mysql - Select distinct/UNIQUE but return all columns?
...
You're looking for a group by:
select *
from table
group by field1
Which can occasionally be written with a distinct on statement:
select distinct on field1 *
from table
On most platforms, however, neither of the above will work because the behavior on the other co...
Facebook database design?
...
Keep a friend table that holds the UserID and then the UserID of the friend (we will call it FriendID). Both columns would be foreign keys back to the Users table.
Somewhat useful example:
Table Name: User
Columns:
UserID PK
Emai...