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Database Design for Tagging
...e fine and scale out assuming the right b-tree indexes exist on the middle table
– Adam Musch
Feb 24 '10 at 16:41
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How can I combine multiple rows into a comma-delimited list in Oracle? [duplicate]
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Here is a simple way without stragg or creating a function.
create table countries ( country_name varchar2 (100));
insert into countries values ('Albania');
insert into countries values ('Andorra');
insert into countries values ('Antigua');
SELECT SUBSTR (SYS_CONNECT_BY_PATH (country_na...
String replacement in batch file
...ABLEDELAYEDEXPANSION switch set.
setlocal ENABLEDELAYEDEXPANSION
set word=table
set str="jump over the chair"
set str=%str:chair=!word!%
share
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follo...
Extract date (yyyy/mm/dd) from a timestamp in PostgreSQL
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Use the date function:
select date(timestamp_field) from table
From a character field representation to a date you can use:
select date(substring('2011/05/26 09:00:00' from 1 for 10));
Test code:
create table test_table (timestamp_field timestamp);
insert into test_table (tim...
How to check which locks are held on a table
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You can find current locks on your table by following query.
USE yourdatabase;
GO
SELECT * FROM sys.dm_tran_locks
WHERE resource_database_id = DB_ID()
AND resource_associated_entity_id = OBJECT_ID(N'dbo.yourtablename');
See sys.dm_tran_locks
If multip...
How to count TRUE values in a logical vector
...values.
See for example:
z <- c(TRUE, FALSE, NA)
sum(z) # gives you NA
table(z)["TRUE"] # gives you 1
length(z[z == TRUE]) # f3lix answer, gives you 2 (because NA indexing returns values)
So I think the safest is to use na.rm = TRUE:
sum(z, na.rm = TRUE) # best way to count TRUE values
(whi...
Is there a Java API that can create rich Word documents? [closed]
... I'll be working on where I have to generate a Word document that contains tables, graphs, a table of contents and text. What's a good API to use for this? How sure are you that it supports graphs, ToCs, and tables? What are some hidden gotcha's in using them?
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Accessing Google Spreadsheets with C# using Google Data API
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Ultimately I need to get the information from Google spreadsheet in a DataTable.
How can I do it? If anyone has attempted it, pls share some information.
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Ordering by the order of values in a SQL IN() clause
...inputted by the query in MS SQL Server 2008+, it can be done by creating a table on the fly and doing a join like so (using nomenclature from OP).
SELECT table1.name, table1.description ...
FROM (VALUES (id1,1), (id2,2), (id3,3) ...) AS orderTbl(orderKey, orderIdx)
LEFT JOIN table1 ON orderTbl.or...
Why can't a text column have a default value in MySQL?
If you try to create a TEXT column on a table, and give it a default value in MySQL, you get an error (on Windows at least). I cannot see any reason why a text column should not have a default value. No explanation is given by the MySQL documentation. It seems illogical to me (and somewhat frustrati...