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What is causing ERROR: there is no unique constraint matching given keys for referenced table?
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In postgresql all foreign keys must reference a unique key in the parent table, so in your bar table you must have a unique (name) index.
See also http://www.postgresql.org/docs/9.1/static/ddl-constraints.html#DDL-CONSTRAINTS-FK and speci...
Conda: Installing / upgrading directly from github
Can I install/upgrade packages from GitHub using conda ?
4 Answers
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Moq mock method with out specifying input parameter
...le parameter? Is it possible to just say "Anything where the types fit for all parameters"?
– Brandon
Mar 2 '16 at 19:13
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Simple calculations for working with lat/lon and km distance?
...long coordinates are expressed in degrees, while the cos function in most (all?) languages typically accepts radians, therefore a degree to radians conversion is needed.
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difference between iframe, embed and object elements
...before that it was a non standard tag, which admittedly was implemented by all major browsers. Behaviour prior to HTML 5 can vary ...
The embed element provides an integration point for an external (typically non-HTML) application or interactive content. (HTML 5 standard - "The <embed> elemen...
Why define an anonymous function and pass it jQuery as the argument?
...de demo code from the backbone.js screencasts. In it, the backbone code is all enclosed in an anonymous function that is passed the jQuery object:
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Change a column type from Date to DateTime during ROR migration
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This answer is only partially correct, you can not use change_column inside change even on rails 4 or down migration will not work. You should use up/down no matter the version of rails.
– Alan Peabody
Jul 18 '1...
Ajax using https on an http page
...d https protocol; it doesn't affect the content. My site uses jQuery ajax calls, which fills some areas on the page, too.
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How to delete from select in MySQL?
...n result sets. So you need to use IN, not = in your WHERE clause.
Additionally, as shown in this answer you cannot modify the same table from a subquery within the same query. However, you can either SELECT then DELETE in separate queries, or nest another subquery and alias the inner subquery resul...
Are SVG parameters such as 'xmlns' and 'version' needed?
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All user agents (browsers) ignore the version attribute, so you can always drop that.
If you embed your SVG inline in a HTML page and serve that page as text/html then xmlns attributes are not required. Embedding SVG inline ...