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How do you use script variables in psql?

...t myvariable value ... and can then be substituted, for example, as ... SELECT * FROM :myvariable.table1; ... or ... SELECT * FROM table1 WHERE :myvariable IS NULL; edit: As of psql 9.1, variables can be expanded in quotes as in: \set myvariable value SELECT * FROM table1 WHERE column1 ...
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Clear form fields with jQuery

... A small tip: this selector won't select input elements that are relying on the implicit type=text, you must explicitly include the type=text on your markup. That may be obvious, but it wasn't to me, just now :-) – Elbin ...
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How to concatenate strings of a string field in a PostgreSQL 'group by' query?

...at the question asked for, even letting you specify the delimiter string: SELECT company_id, string_agg(employee, ', ') FROM mytable GROUP BY company_id; Postgres 9.0 also added the ability to specify an ORDER BY clause in any aggregate expression; otherwise, the order is undefined. So you can no...
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How can I check whether a radio button is selected with JavaScript?

...when one of the fields is null. How can I check whether a radio button is selected? 28 Answers ...
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How to check if a file is a valid image file?

... A lot of times the first couple chars will be a magic number for various file formats. You could check for this in addition to your exception checking above. share | ...
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SQL Server Insert if not exists

..., Assunto, Data) VALUES (@_DE, @_ASSUNTO, @_DATA) WHERE NOT EXISTS ( SELECT * FROM EmailsRecebidos WHERE De = @_DE AND Assunto = @_ASSUNTO AND Data = @_DATA); END replace with BEGIN IF NOT EXISTS (SELECT * FROM EmailsRecebidos ...
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XPath to select multiple tags

...l-name()='e'] is both too-long and incorrect. This XPath expression will select nodes like: OhMy:c NotWanted:d QuiteDifferent:e share | improve this answer | follow ...
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What is the worst real-world macros/pre-processor abuse you've ever come across?

...efine static #define void int #define main(x) main() struct F{void println(char* s){std::cout << s << std::endl;}}; struct S{F out;}; public static void main(String[] args) { System.out.println("Hello World!"); } Challenge: Can anyone do it with fewer defines and structs? ;-) ...
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Trigger change event of dropdown

...wns, the best way to do it is to have a script that returns the a prebuilt select box and an AJAX call that requests it. Here is the documentation for jQuery's Ajax method if you need it. $(document).ready(function(){ $('#countrylist').change(function(e){ $this = $(e.target); ...
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Cannot truncate table because it is being referenced by a FOREIGN KEY constraint?

... IF OBJECT_ID('tempdb..#FKs') IS NOT NULL DROP TABLE #FKs -- GET FKs SELECT ROW_NUMBER() OVER (ORDER BY OBJECT_NAME(parent_object_id), clm1.name) as ID, OBJECT_NAME(constraint_object_id) as ConstraintName, OBJECT_NAME(parent_object_id) as TableName, clm1.name as ColumnName...