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Is it possible to GROUP BY multiple columns using MySQL?
...garding SUM using with GROUP BY. If GROUP BY only by one column, then SUMs all values of each distinct (different) the column value sqlfiddle.com/#!9/1cbde2/2. If GROUP BY two columns. Then mysql at first checks if for the first column value there are different values in the second column. If yes, t...
Why does my JavaScript code receive a “No 'Access-Control-Allow-Origin' header is present on the req
...ferent domain than your page is on. So the browser is blocking it as it usually allows a request in the same origin for security reasons. You need to do something different when you want to do a cross-domain request. A tutorial about how to achieve that is Using CORS.
When you are using postman the...
postgresql list and order tables by size
How can I list all the tables of a PostgreSQL database and order them by size ?
7 Answers
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How to generate UML diagrams (especially sequence diagrams) from Java code?
... choice it's very advanced and full of features, but if you just want to sketch out some UML diagrams and easy installation then ObjectAid is pretty cool and it doesn't require any plugins I just installed it over Eclipse-Java EE and works great !.
UPDATE Oct 11th, 2013
My original post was in...
Why unsigned integer is not available in PostgreSQL?
I came across this post ( What is the difference between tinyint, smallint, mediumint, bigint and int in MySQL? ) and realized that PostgreSQL does not support unsigned integer.
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How to delete every other line in Vim?
...e from a Vim buffer, starting with the second one, i.e., lines 2, 4, 6, etc. For example, if the buffer’s contents is:
...
How do I use cascade delete with SQL Server?
...o perform cascading delete in SQL Server when a record from T1 is deleted, all associated records in T2 also deleted.
8 An...
What is the point of noreturn?
... to the caller -- for example because you call exit(), abort(), assert(0), etc.
– RavuAlHemio
Nov 11 '14 at 19:56
7
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How do I output coloured text to a Linux terminal?
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You need to output ANSI colour codes. Note that not all terminals support this; if colour sequences are not supported, garbage will show up.
Example:
cout << "\033[1;31mbold red text\033[0m\n";
Here, \033 is the ESC character, ASCII 27. It is followed by [, then zero o...
How To Change DataType of a DataColumn in a DataTable?
... of the column after the DataTable is filled, you can change it after you call FillSchema, but before you call Fill. For example, say the 3rd column is the one you want to convert from double to Int32, you could use:
adapter.FillSchema(table, SchemaType.Source);
table.Columns[2].DataType = typeof (...