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SQL MAX of multiple columns?
...(VALUES (date1), (date2), (date3),...) AS value(v)) as [MaxDate]
FROM [YourTableName]
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What is the difference between NTFS Junction Points and Symbolic Links?
...ts, but Junction Points most definitely are not Symbolic Links! Oh and the table is wrong on one count also. The target of a Junction Point must exist upon creation, but it may indeed be removed later on.
– 0xC0000022L
Oct 22 '18 at 11:50
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insert a NOT NULL column to an existing table
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As an option you can initially create Null-able column, then update your table column with valid not null values and finally ALTER column to set NOT NULL constraint:
ALTER TABLE MY_TABLE ADD STAGE INT NULL
GO
UPDATE MY_TABLE SET <a valid not null values for your column>
GO
ALTER TABLE MY_TA...
Best way to center a on a page vertically and horizontally? [duplicate]
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@FlashThunder you suggest tables for non-table data, aren't you?
– Vladimir Starkov
Jan 10 '15 at 3:17
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What are database normal forms and can you give examples? [closed]
...y normalization, which is a process of organizing columns (attributes) and tables (relations) to reduce data redundancy and improve data integrity. (as written on Wikipedia ).
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Why are joins bad when considering scalability?
...ted comparison for a join is now much smaller and potentially pre-indexed.
Table partitions (helps with large data sets by spreading the load out to multiple disks, or limiting what might have been a table scan down to a partition scan)
OLAP (pre-computes results of certain kinds of queries/joins. I...
NULL values inside NOT IN clause
...s one using a not in where constraint and the other a left join . The table in the not in constraint had one null value (bad data) which caused that query to return a count of 0 records. I sort of understand why but I could use some help fully grasping the concept.
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Group by multiple columns in dplyr, using string vector input
...e
df2 <- plyr::ddply(data, columns, plyr::summarize, value=mean(value))
table(df1 == df2, useNA = 'ifany')
## TRUE
## 27
The output from your example question is as expected (see comparison to plyr above and output below):
# A tibble: 9 x 3
# Groups: asihckhdoydkhxiydfgfTgdsx [?]
asihck...
Extracting hours from a DateTime (SQL Server 2005)
...dd(hour,12,time_received)
else time_received
END
from table
works
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Copy table without copying data
copies the table foo and duplicates it as a new table called bar .
4 Answers
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