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Insert, on duplicate update in PostgreSQL?
...CT clause. with the following syntax (similar to MySQL)
INSERT INTO the_table (id, column_1, column_2)
VALUES (1, 'A', 'X'), (2, 'B', 'Y'), (3, 'C', 'Z')
ON CONFLICT (id) DO UPDATE
SET column_1 = excluded.column_1,
column_2 = excluded.column_2;
Searching postgresql's email group arch...
App Inventor 2 列表代码块 · App Inventor 2 中文网
...出异常、报错。
如果给定列表是一个二维列表，如 [["abc","123"],["xyz","456"]] ，则返回的列表项也是一个列表对象，如 ["abc","123"]。
求对象在列表中的位置
返回指定对象在列表中的位置，从 1 开始，如果不在列表中，则返回 0...
delegate keyword vs. lambda notation
Once it is compiled, is there a difference between:
6 Answers
6
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Why is it impossible to override a getter-only property and add a setter? [closed]
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Because the writer of Baseclass has explicitly declared that Bar has to be a read-only property. It doesn't make sense for derivations to break this contract and make it read-write.
I'm with Microsoft on this one.
Let's say ...
How to upper case every first letter of word in a string? [duplicate]
...ing with .toUpperCase(). Is there an existing java helper which does the job?
16 Answers
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In Python, how do I indicate I'm overriding a method?
...verride annotation not only provides compile-time checking of an override but makes for excellent self-documenting code.
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How to find the type of an object in Go?
How do I find the type of an object in Go? In Python, I just use typeof to fetch the type of object. Similarly in Go, is there a way to implement the same ?
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constant pointer vs pointer on a constant value [duplicate]
What is the difference between the following declarations?
11 Answers
11
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How do you specify a byte literal in Java?
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You cannot. A basic numeric constant is considered an integer (or long if followed by a "L"), so you must explicitly downcast it to a byte to pass it as a parameter. As far as I know there is no shortcut.
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Git undo changes in some files [duplicate]
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There are three basic ways to do this depending on what you have done with the changes to the file A. If you have not yet added the changes to the index or committed them, then you just want to use the checkout command - this will change the...