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Is storing a delimited list in a database column really that bad?
...nt table-scan. May have to resort to regular expressions, for example in MySQL:
idlist REGEXP '[[:<:]]2[[:>:]]'*
Hard to count elements in the list, or do other aggregate queries.
Hard to join the values to the lookup table they reference.
Hard to fetch the list in sorted order.
To solve thes...
django syncdb and an updated model
...m using South for migrating models with a custom db backend (like django-mssql)
– Don
Apr 4 '11 at 7:32
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How to ALTER multiple columns at once in SQL Server
...simple metadata change. You are welcome to join my lecture tomorrow about "SQL Internals - Physical Table Structure under the hood, and implementation on real case scenarios" to see it all in practical :-)
– Ronen Ariely
Mar 12 '19 at 17:19
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Is there any boolean type in Oracle databases?
... any Boolean type in Oracle databases, similar to the BIT datatype in Ms SQL Server?
11 Answers
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Oracle: how to UPSERT (update or insert into a table?)
...before the insert regardless of how many concurrent calls are made to same SQL code. Worst case, you may get lots of contention and Oracle will take much longer to reach a final state.
– Neo
Nov 6 '12 at 13:23
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How to split a string literal across multiple lines in C / Objective-C?
I have a pretty long sqlite query:
9 Answers
9
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Postgis installation: type “geometry” does not exist
...eate table with Postgis. I do it by this page . But when I import postgis.sql file, I get a lot of errors:
10 Answers
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Postgres: INSERT if does not exist already
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@TusharJain prior to PostgreSQL 9.5 you can do an "old fashioned" UPSERT (with CTE) but you may experience problems with race conditions and it will not be performant as 9.5 style. There is a good detail about upsert on this blog (in the updated area at...
What is causing this ActiveRecord::ReadOnlyRecord error?
... you use this option, saving the same
record will now fail. Use find_by_sql
to work around.
Using find_by_sql is not really an alternative as it returns raw row/column data, not ActiveRecords. You have two options:
Force the instance variable @readonly to false in the record (hack)
Use :in...
MySQL: selecting rows where a column is null
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SQL NULL's special, and you have to do WHERE field IS NULL, as NULL cannot be equal to anything,
including itself (ie: NULL = NULL is always false).
See Rule 3 https://en.wikipedia.org/wiki/Codd%27s_12_rules
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