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Quickest way to compare two generic lists for differences
...ist = list1.Where(a => !list2.Any(a1 => a1.id == a.id))
.Union(list2.Where(a => !list1.Any(a1 => a1.id == a.id)));
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foll...
Useful GCC flags for C
...rning.
-Waggregate-return: warn if any functions that return structures or unions are defined or called.
-Wcast-qual: warn whenever a pointer is cast to remove a type qualifier from the target type*.
-Wswitch-default: warn whenever a switch statement does not have a default case*.
-Wswitch-enum: war...
How to use GROUP BY to concatenate strings in SQL Server?
...s
(
select OUTPUTID, convert(varchar(max),combined), 1 from cte where rn=1
union all
select cte2.outputid, convert(varchar(max),cte2.finalstatus+', '+cte.combined), cte2.rn+1
from cte2
inner join cte on cte.OUTPUTID = cte2.outputid and cte.rn=cte2.rn+1
)
select outputid, MAX(finalstatus) from cte2 g...
How do I concatenate two lists in Python?
...
+1 IMHO this is the correct way to "merge" (union) lists while the "approved" answer describes how to combine/add lists (multiset)
– Nir Alfasi
Apr 27 '14 at 4:07
...
Extract a dplyr tbl column as a vector
...masked from 'package:base':
#>
#> intersect, setdiff, setequal, union
db <- src_sqlite(tempfile(), create = TRUE)
iris2 <- copy_to(db, iris)
vec <- pull(iris2, Species)
head(vec)
#> [1] "setosa" "setosa" "setosa" "setosa" "setosa" "setosa"
...
Postgres: INSERT if does not exist already
...le in Postgres:
INSERT INTO person (name)
SELECT name FROM person
UNION
VALUES ('Bob')
EXCEPT
SELECT name FROM person;
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How do you find the disk size of a Postgres / PostgreSQL table and its indexes
... where table_schema = 'public' and table_type = 'BASE TABLE'
union
-- materialized views
SELECT oid::regclass::text as table_name
FROM pg_class
WHERE relkind = 'm'
order by table_name
) AS all_tables
-- ORDER BY total_size DESC
order ...
How to randomly select rows in SQL?
...CLARE @range int = @maxValue+1 - @minValue;
with cte (n) as (
select 1 union all
select n+1 from cte
where n < @NumItems
)
select cast( @range * rand(cast(newid() as varbinary(100))) + @minValue as int) tp
into #Nt
from cte;
select * from #Nt ntt
inner join [TABLE] i on i.id = ntt.tp;
...
SQL how to make null values come last when sorting ascending
...d to compare the column in question to another date column. I use this for union seniority list. If employee has a Qualified date (which is nullable) , that date bubbles record to the top, otherwise use HireDate. Using ORDER BY ISNULL(QualifiedDate,'1-1-2099') , HireDate ,LastName, etc makes the Qu...
Condition within JOIN or WHERE
...left/right table rows extended by NULLs. FULL JOIN returns INNER JOIN rows UNION ALL unmatched left & right table rows extended by NULLs. Always know what INNER JOIN you want as part of an OUTER JOIN. A WHERE or ON that requires a possibly NULL-extended column to be not NULL after an OUTER JOIN ...