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Difference between Select Unique and Select Distinct
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Unique is a keyword used in the Create Table() directive to denote that a field will contain unique data, usually used for natural keys, foreign keys etc.
For example:
Create Table Employee(
Emp_PKey Int Identity(1, 1) Constraint PK_Employee_Emp_PKey Prim...
How to make an inline-block element fill the remainder of the line?
...e using CSS and two inline-block (or whatever) DIV tags instead of using a table?
7 Answers
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MySQL high CPU usage [closed]
... time, and use that to make sure you don't have any queries locking up key tables for too long.
Some other things you can check would be to run the following query while the CPU load is high:
SHOW PROCESSLIST;
This will show you any queries that are currently running or in the queue to run, what...
Cast int to varchar
...wing SQL — in action — over at SQL Fiddle:
/*! Build Schema */
create table t9 (id INT, name VARCHAR(55));
insert into t9 (id, name) values (2, 'bob');
/*! SQL Queries */
select CAST(id as CHAR(50)) as col1 from t9;
select CONVERT(id, CHAR(50)) as colI1 from t9;
Besides the fact that you w...
parseInt vs unary plus, when to use which?
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The ultimate whatever-to-number conversion table:
EXPRS = [
'parseInt(x)',
'parseFloat(x)',
'Number(x)',
'+x',
'~~x',
'x>>>0',
'isNaN(x)'
];
VALUES = [
'"123"',
'"+123"',
'"-123"',
'"123.45"',...
UITableView didSelectRowAtIndexPath: not being called on first tap
I'm having an issue with UITableView's didSelectRowAtIndexPath .
16 Answers
16
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Removing a model in rails (reverse of “rails g model Title…”)
...oy' on that model, it will delete the migration file, but not the database table. So before run
bundle exec rake db:rollback
share
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follow
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Improve INSERT-per-second performance of SQLite
...f possible, which will replace the implied unique row number column in the table.
If you are using multiple threads, you can try using the shared page cache, which will allow loaded pages to be shared between threads, which can avoid expensive I/O calls.
Don't use !feof(file)!
I've also asked simi...
Using backticks around field names
...r field` , `field,with,comma`
Which does of course generate badly named tables.
If you're just being concise I don't see a problem with it,
you'll note if you run your query as such
EXPLAIN EXTENDED Select foo,bar,baz
The generated warning that comes back will have back-ticks and fully qua...
How to use GROUP BY to concatenate strings in SQL Server?
...5 and later. Original question didn't specify the version in use.]
CREATE TABLE #YourTable ([ID] INT, [Name] CHAR(1), [Value] INT)
INSERT INTO #YourTable ([ID],[Name],[Value]) VALUES (1,'A',4)
INSERT INTO #YourTable ([ID],[Name],[Value]) VALUES (1,'B',8)
INSERT INTO #YourTable ([ID],[Name],[Value]...