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SQL Server Regular expressions in T-SQL
... of people to SQL Server. The "people" are from the [Application].[People] table in the [WideWorldImporters] sample database. They get passed to the R engine as a dataframe named InputDataSet. R uses the grepl function with the "not" operator (exclamation point!) to find which people have email addr...
Best way to synchronize local HTML5 DB (WebSQL Storage, SQLite) with a server (2 way sync) [closed]
...ize the lib (at each startup for example).
It will automatically create 2 tables (if they don't already exists, one to store all the new or modified elements (table new_elem) and one to store the date of the last sync (table sync_info). It will also create SQLite triggers in order to watch the INSE...
How to remove a lua table entry by its key?
I have a lua table that I use as a hashmap, ie with string keys :
1 Answer
1
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How to get cumulative sum
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@Franklin Only cost efficient for small tables. Cost grows proportional to the square of the number of rows. SQL Server 2012 allows this to be done much more efficiently.
– Martin Smith
May 18 '13 at 19:57
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Save PL/pgSQL output from PostgreSQL to a CSV file
...rticular directory, for instance, and the filename might have to have a suitable prefix or extension.
Which tables should the user be able to read/write in the database? This would normally be defined by GRANTs in the database, but the function is now running as a superuser, so tables which would no...
SQL JOIN vs IN performance?
... faster more often than not.
So if you are only interested in values from table a you can use this query:
SELECT a.*
FROM a
WHERE EXISTS (
SELECT *
FROM b
WHERE b.col = a.col
)
The difference might be huge if col is not indexed, because the db does not have to find al...
When to Redis? When to MongoDB? [closed]
... need to change your schema quickly.
Because there is no schema! Altering tables in traditional, relational DBMS is painfully expensive and slow. MongoDB solves this problem by not making a lot of assumptions on your underlying data. Nevertheless, it tries to optimize as far as possible without req...
Populate data table from data reader
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You can load a DataTable directly from a data reader using the Load() method that accepts an IDataReader.
var dataReader = cmd.ExecuteReader();
var dataTable = new DataTable();
dataTable.Load(dataReader);
...
Should MySQL have its timezone set to UTC?
...`timestamp_field`, @@session.time_zone, '+00:00') AS `utc_datetime`
FROM `table_name`
You can also set the sever or global or current session timezone to UTC and then select the timestamp like so:
SELECT `timestamp_field` FROM `table_name`
To select the current datetime in UTC:
SELECT UTC_TIM...
How to force table cell content to wrap?
...
Use table-layout:fixed in the table and word-wrap:break-word in the td.
See this example:
<html>
<head>
<style>
table {border-collapse:collapse; table-layout:fixed; width:310px;}
table td {border:soli...