大约有 47,000 项符合查询结果(耗时:0.0331秒) [XML]

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Is it possible to roll back CREATE TABLE and ALTER TABLE statements in major SQL databases?

...es. Also, not all situations are quite handled- for example, if you try to select from table foo while another transaction is dropping it and creating a replacement table foo, then the blocked transaction will finally receive an error rather than finding the new foo table. (Edit: this was fixed in o...
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Error 1022 - Can't write; duplicate key in table

...ere the constraints are currently in use you can use the following query: SELECT `TABLE_SCHEMA`, `TABLE_NAME` FROM `information_schema`.`KEY_COLUMN_USAGE` WHERE `CONSTRAINT_NAME` IN ('iduser', 'idcategory'); share ...
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How Pony (ORM) does its tricks?

...s query: >>> from pony.orm.examples.estore import * >>> select(c for c in Customer if c.country == 'USA').show() Which will be translated into the following SQL: SELECT "c"."id", "c"."email", "c"."password", "c"."name", "c"."country", "c"."address" FROM "Customer" "c" WHERE "c"...
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How to make rounded percentages add up to 100%

...original, decimal forceSum, int decimals) { var rounded = original.Select(x => Math.Round(x, decimals)).ToList(); Debug.Assert(Math.Round(forceSum, decimals) == forceSum); var delta = forceSum - rounded.Sum(); if (delta == 0) return rounded; var deltaUnit = Convert.ToDecim...
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Exclude .svn directories from grep [duplicate]

...tput of first grep as input (via piping). By using the -v flag, grep will select the lines which DON'T match the search terms. Voila. You are left with all the ouputs from the first grep which do not contain .svn in the filepath. -v, --invert-match Invert the sense of matching, to select n...
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How can I get all constants of a type by reflection?

...mp;& !fi.IsInitOnly && fi.FieldType == typeof(T)) .Select(x => (T)x.GetRawConstantValue()) .ToList(); } } Then for a class like this static class MyFruitKeys { public const string Apple = "apple"; public const string Plum = "plum"; public con...
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How to move columns in a MySQL table?

...min provides a GUI for this within the structure view of a table. Check to select the column you want to move and click the change action at the bottom of the column list. You can then change all of the column properties and you'll find the 'move column' function at the far right of the screen. Of ...
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NSInvalidUnarchiveOperationException: Could not instantiate class named NSLayoutConstraint

...the first tab in the left hand side inspector, when you have File's owner) selected. share | improve this answer | follow | ...
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Should I use “hasClass” before “addClass”? [duplicate]

... Hey Jon :) It is mouse selectable as well.. (click on line number and shift+click on another to select all lines..) – Gabriele Petrioli Nov 13 '12 at 10:30 ...
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How can I delete multiple lines in vi?

... I find this easier Go VISUAL mode Shift+v Select lines d to delete https://superuser.com/questions/170795/how-can-i-select-and-delete-lines-of-text-in-vi share | i...