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SQL Server IN vs. EXISTS Performance
... test case does not mean that the optimizer will do the exact same plan on tables with different statistics. This might lead someone to think the answer is partial - but the nonexistence of multiple semijoin operators is fact. Maybe I'll find a list somewhere and link it.
– Geo...
what is faster: in_array or isset? [closed]
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@Fabrizio - Read up on hashing functions and hash tables.
– David Harkness
Nov 20 '12 at 22:54
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show 5 more commen...
SQL RANK() versus ROW_NUMBER()
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Look this example.
CREATE TABLE [dbo].#TestTable(
[id] [int] NOT NULL,
[create_date] [date] NOT NULL,
[info1] [varchar](50) NOT NULL,
[info2] [varchar](50) NOT NULL,
)
Insert some data
INSERT INTO dbo.#TestTable (id, create_date, in...
Replacement for deprecated sizeWithFont: in iOS 7?
...n the main thread (like any other UIKit functionality), you'll get unpredictable behaviors. In particular, if you ran the function on multiple threads simultaneously, it'll probably crash your app. This is why in iOS 6, they introduced a the boundingRectWithSize:... method for NSAttributedString. ...
Better techniques for trimming leading zeros in SQL Server?
...eading-zero's.
If you plan on reusing it a lot, then place it in an Inline-Table-Valued-Function (ITVF).
Your concerns about performance problems with UDF's is understandable.
However, this problem only applies to All-Scalar-Functions and Multi-Statement-Table-Functions.
Using ITVF's is perfectly fi...
Code-first vs Model/Database-first [closed]
... unique index on a field or you can not delete hierarchical data in a tree table for this you need a CTE using the context.Table.SqlQuery("select..."). Model/Database first do not have these drawbacks.
– Elisabeth
Jan 31 '13 at 13:51
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What does the KEY keyword mean?
In this MySQL table definition:
2 Answers
2
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SQL UPDATE all values in a field with appended string CONCAT not working
...rver 'data' was a keyword. Maybe a less ambiguous example would be: UPDATE table SET column_name=concat(column_name, 'string');
– Kiky Rodriguez
Dec 11 '18 at 19:09
add a comm...
How can I deserialize JSON to a simple Dictionary in ASP.NET?
..."id\":\"13\", \"value\": true}";
var jss = new JavaScriptSerializer();
var table = jss.Deserialize<dynamic>(json);
Console.WriteLine(table["id"]);
Console.WriteLine(table["value"]);
share
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i...
best practice to generate random token for forgot password
...rch in about a week's time for a low-budget attacker:
mt_rand() is predictable (and only adds up to 31 bits of entropy)
uniqid() only adds up to 29 bits of entropy
md5() doesn't add entropy, it just mixes it deterministically
Since a 56-bit DES key can be brute-forced in about 24 hours, and an a...