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What is the difference between single and double quotes in SQL?
...stant or a date/time constant.
Double quotes delimit identifiers for e.g. table names or column names. This is generally only necessary when your identifier doesn't fit the rules for simple identifiers.
See also:
Do different databases use different name quote?
You can make MySQL use double-q...
How to add a footer to a UITableView in Storyboard
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You can just drag a view to the bottom area of the tableView. You'll see in the hierarchy that it will be a subview of the tableview. You can then drag subviews such as labels and buttons there, adjust the height, etc.
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Tricks to manage the available memory in an R session
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I use the data.table package. With its := operator you can :
Add columns by reference
Modify subsets of existing columns by reference, and by group by reference
Delete columns by reference
None of these operations copy the (potentially...
How to vertically align elements in ?
...n, you're not worrying about IE or older browsers.
So you can use display:table-cell and display:table-row like so:
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.or...
JavaScript variable number of arguments to function
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+1 This is elegant and clean solution. Especially suitable for passing through long list of parameters into another function call, and with possible that those variable parameters are at arbitrary position.
– haxpor
Sep 6 '17 at 7:55
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Find document with array that contains a specific value
...nd that such solutions work so simply without needing JOINs and additional tables makes me wonder why I haven't started on Mongo sooner. But that's not to say either DBMS is superior over the other - it depends on your use case.
– Irvin Lim
Jun 18 '15 at 14:37
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What do column flags mean in MySQL Workbench?
In MySQL Workbench table editor there are 7 column flags available: PK, NN, UQ, BIN, UN, ZF, AI.
3 Answers
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switch case statement error: case expressions must be constant expression
...lookup involved (first on the internal SparseArray and later on the switch table)
That said, this enum can also be utilised to fetch the items in a fluent manner, if needed by keeping a reference to the id... but that's a story for some other time.
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MySQL 启动报错 Table \'mysql.plugin\' doesn\'t exist - 数据库(内核) -...
MySQL 启动报错 Table 'mysql.plugin' doesn't exist 启动报错： opt szy bin mysqld: Table 'mysql.plugin ' doesn 't exist141211 15:06:12 [ERROR] Can 't open t...启动报错：
/opt/szy/bin/mysqld: Table \'mysql.plugin\' doesn\'t exist
141211 15:06:12 [ERROR] Can\'t open the mysql.plug...
MySQL SELECT WHERE datetime matches day (and not necessarily time)
I have a table which contains a datetime column. I wish to return all records of a given day regardless of the time. Or in other words, if my table only contained the following 4 records, then only the 2nd and 3rd would be returned if I limit to 2012-12-25.
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