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insert multiple rows via a php array into mysql
I'm passing a large dataset into a MySQL table via PHP using insert commands and I'm wondering if its possible to insert approximately 1000 rows at a time via a query other than appending each value on the end of a mile long string and then executing it. I am using the CodeIgniter framework so its f...
MySQL Orderby a number, Nulls last
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MySQL has an undocumented syntax to sort nulls last. Place a minus sign (-) before the column name and switch the ASC to DESC:
SELECT * FROM tablename WHERE visible=1 ORDER BY -position DESC, id DESC
It is essentially the...
Citrix服务器虚拟化：XenApp 6.5发布服务器上的应用程序 - 更多技术 - 清泛...
...的其他应用程序旁边。用户无须了解应用程序在何处以及如何执行。
8) 脱机访问:配置并交付之后，应用程序在断开网络连接后也可供用户使用。
9) 易于灾难恢复:按需应用程序交付对灾难恢复状况而言是一个强大的概念，...
How to add new column to MYSQL table?
I am trying to add a new column to my MYSQL table using PHP. I am unsure how to alter my table so that the new column is created. In my assessment table I have:
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What is the difference between MySQL, MySQLi and PDO? [closed]
What is the difference between MySQL, MySQLi and PDO ?
4 Answers
4
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What's the difference between comma separated joins and join on syntax in MySQL? [duplicate]
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This answer is not correct. In the MySQL manual on the page dev.mysql.com/doc/refman/5.5/en/join.html it states: "However, the precedence of the comma operator is less than that of INNER JOIN, CROSS JOIN, LEFT JOIN, and so on. If you mix comma joins with the o...
MySQL: selecting rows where a column is null
...E userid = NULL;
This will not give you the expected result, because from mysql doc
In SQL, the NULL value is never true in comparison to any other value, even NULL. An expression that contains NULL always produces a NULL value unless otherwise indicated in the documentation for the operators and ...
Select mySQL based only on month and year
I have a column in my mySQL DB that has some rows. One of this row is a DATE, like this: 2012-02-01
12 Answers
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MySQL “NOT IN” query
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NOT IN vs. NOT EXISTS vs. LEFT JOIN / IS NULL in MySQL
MySQL, as well as all other systems except SQL Server, is able to optimize LEFT JOIN / IS NULL to return FALSE as soon the matching value is found, and it is the only system that cared to document this behavior.
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Mysql: Select rows from a table that are not in another
... this only works as expected when none of the columns have NULL values. In MySQL NULL != NULL so every row that has a NULL value will be returned even if there is a duplicate row in the second table.
– Kyle Kochis
Apr 7 '15 at 2:49
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