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SQL RANK() versus ROW_NUMBER()

...bout the differences between these. Running the following SQL gets me two idential result sets. Can someone please explain the differences? ...
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Trigger a button click with JavaScript on the Enter key in a text box

...t to trigger the button's click event when the Enter key is pressed inside the text box? 30 Answers ...
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Drop a temporary table if it exists

... IF EXISTS ##CLIENTS_KEYWORD On previous versions you can use IF OBJECT_ID('tempdb..##CLIENTS_KEYWORD', 'U') IS NOT NULL /*Then it exists*/ DROP TABLE ##CLIENTS_KEYWORD CREATE TABLE ##CLIENTS_KEYWORD ( client_id INT ) You could also consider truncating the table instead rather than dropping ...
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how to add records to has_many :through association in rails

...mer.new(params[:customer]) @cust.houses << House.find(params[:house_id]) Or when creating a new house for a customer: @cust = Customer.new(params[:customer]) @cust.houses.create(params[:house]) You can also add via ids: @cust.house_ids << House.find(params[:house_id]) ...
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MySQL和MongoDB设计实例进行对比 - 大数据 & AI - 清泛网 - 专注C/C++及内核技术

...数表来单独保存。 CREATE TABLE IF NOT EXISTS `mobiles` ( `id` int(10) unsigned NOT NULL AUTO_INCREMENT, `name` VARCHAR(100) NOT NULL, `brand` VARCHAR(100) NOT NULL, PRIMARY KEY (`id`) ); CREATE TABLE IF NOT EXISTS `mobile_params` ( `id` int(10) unsigned NOT NUL...
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两种js滑动门(tab切换)效果 - 源码下载 - 清泛网 - 专注C/C++及内核技术

...d: #fff; text-align: center; margin: 0; } .nTab{ float: left; width: 960px; margin: 0 auto; border-bottom:1px #AACCEE solid; background:#d5d5d5; background-position:left; background-repeat:repeat-y; margin-bottom:2px; } .nTab .TabTitle{ clear: both; height: 22px; ov...
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Rails raw SQL example

... side note: records_array will be of different types for different database adapters. If you're using PG, it will be an instance of PG::Result, not Array. – tybro0103 Jan 14 '14 at 17:28 ...
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How to UPSERT (MERGE, INSERT … ON DUPLICATE UPDATE) in PostgreSQL?

...em in useful detail. In general you must choose between two options: Individual insert/update operations in a retry loop; or Locking the table and doing batch merge Individual row retry loop Using individual row upserts in a retry loop is the reasonable option if you want many connections concurre...
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In CMake, how can I test if the compiler is Clang?

... A reliable check is to use the CMAKE_<LANG>_COMPILER_ID variables. E.g., to check the C++ compiler: if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang") # using Clang elseif (CMAKE_CXX_COMPILER_ID STREQUAL "GNU") # using GCC elseif (CMAKE_CXX_COMPILER_ID STREQUAL "Intel") # using ...
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Remove Primary Key in MySQL

...erty before dropping the key: ALTER TABLE user_customer_permission MODIFY id INT NOT NULL; ALTER TABLE user_customer_permission DROP PRIMARY KEY; Note that you have a composite PRIMARY KEY which covers all three columns and id is not guaranteed to be unique. If it happens to be unique, you can m...