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postgresql - sql - count of `true` values
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Since PostgreSQL 9.4 there's the FILTER clause, which allows for a very concise query to count the true values:
select count(*) filter (where myCol)
from tbl;
The above query is a bad example in that a simple WHERE clause would suffice...
Command line: piping find results to rm
I'm trying to work out a command which deletes sql files older than 15 days.
4 Answers
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How do you use variables in a simple PostgreSQL script?
For example, in MS-SQL, you can open up a query window and run the following:
10 Answers
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Using varchar(MAX) vs TEXT on SQL Server
...GB of char data) is the recommended replacement for the TEXT datatype in SQL Server 2005 and Next SQL SERVER versions.
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How to shrink/purge ibdata1 file in MySQL
I am using MySQL in localhost as a "query tool" for performing statistics in R, that is, everytime I run a R script, I create a new database (A), create a new table (B), import the data into B, submit a query to get what I need, and then I drop B and drop A.
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What is your naming convention for stored procedures? [closed]
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Here's some clarification about the sp_ prefix issue in SQL Server.
Stored procedures named with the prefix sp_ are system sprocs stored in the Master database.
If you give your sproc this prefix, SQL Server looks for them in the Master database first, then the context database,...
Rename MySQL database [duplicate]
.... Now I need to change database name to sunhrm . But, It is disabled in MySQL workbench. Can I do that on the Linux server itself?
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Is it possible to use the SELECT INTO clause with UNION [ALL]?
In SQL Server this inserts 100 records, from the Customers table into tmpFerdeen :-
8 Answers
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GROUP BY with MAX(DATE) [duplicate]
...'s answer will tend to perform less I/O. The analytic function allows the SQL to process the the table in a single pass, whereas Oliver's solution requires multiple passes.
– Adam Musch
Aug 16 '10 at 14:33
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Why does Oracle 9i treat an empty string as NULL?
...at doesn't do much to tell me why this is the case. As I understand the SQL specifications, ' ' is not the same as NULL -- one is a valid datum, and the other is indicating the absence of that same information.
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