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Cast int to varchar
... @JonathanSayce I'm not overly familiar with the ins & outs of MySQL and it might not use something arbitrary, but I wouldn't rely on the MySQL engine to be that smart (no offense to MySQL). In order to be sure you get the proper length, I would always explicitly provide one.
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When to use Hadoop, HBase, Hive and Pig?
...ru some SQL like language
To replace daily aggregation data generated thru MySQL with Hive
Build Custom reports thru queries in Hive
Architecture Options
I benchmarked the following options:
Hive+HDFS
Hive+HBase - queries were too slow so I dumped this option
Design
Daily log Files were tr...
App Inventor 2 中文网原创内容 · App Inventor 2 中文网
...科普】App Inventor 2 添加超过10个屏幕会怎样？
【算法】如何计算1加到100的总和？（经典循环的写法）
【算法】App Inventor 2 算法之二分算法（Binary Search）实现，快速查找定位
组件用法
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Is the primary key automatically indexed in MySQL?
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According to http://dev.mysql.com/doc/refman/5.0/en/constraint-primary-key.html it would appear that this is would be implicit
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Convert from MySQL datetime to another format with PHP
I have a datetime column in MySQL.
18 Answers
18
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Can PHP PDO Statements accept the table or column name as parameter?
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I miss mysql_real_escape_string(). Maybe here I can say it without someone jumping in and saying "But you don't need it with PDO"
– Rolf
Oct 20 '18 at 8:39
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MySQL select one column DISTINCT, with corresponding other columns
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@Full Decent you can't, according to MySQL documentation: "The server is free to choose any value from each group, so unless they are the same, the values chosen are indeterminate.". In practice I've successfully used this kind of queries with ORDER BY clause, ...
MySQL: Large VARCHAR vs. TEXT?
I've got a messages table in MySQL which records messages between users. Apart from the typical ids and message types (all integer types) I need to save the actual message text as either VARCHAR or TEXT. I'm setting a front-end limit of 3000 characters which means the messages would never be inserte...
MySQL Conditional Insert
...his, dual is a table with one row only (found originally in Oracle, now in mysql too). The logic is that the SELECT statement generates a single row of data with the required values, but only when the values are not already found.
Alternatively, look at the MERGE statement.
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Linux 进程卡住了怎么办？ - 操作系统(内核) - 清泛网 - 专注C/C++及内核技术
...ffffffff>] 0xffffffffffffffff
这时候按 Ctrl+C 也不能退出。
root@localhost:~# ls /jfs
^C
^C^C^C^C^C
但是用 strace 却能唤醒它，并且开始处理之前的中断信号，然后就退出了。
root@localhost:~# strace -p `pgrep ls`
strace: Process 26469 attached
--- SI...