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SQL Server: Get data for only the past year
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This will have very bad performance on big tables, you query will loop over every record to evaluate the year value of the date, it would be better to use a date range
– Adriaan Davel
May 30 '12 at 15:43
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How can I get dict from sqlite query?
... dictionaries, each item in list(each dictionary)
#represents a row of the table
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A std::map that keep track of the order of insertion?
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You might combine a std::vector with a std::tr1::unordered_map (a hash table). Here's a link to Boost's documentation for unordered_map. You can use the vector to keep track of the insertion order and the hash table to do the frequent lookups. If you're doing hundreds of thousands of lookups,...
How can I automate the “generate scripts” task in SQL Server Management Studio 2008?
...or the database publishing wizard (sqlpubwiz.exe). It's not currently scriptable from the command line, I might add that contribution in the future.
Scriptio was originally posted on Bill Graziano's blog, but has subsequently been released to CodePlex by Bill and updated by others. Read the discuss...
Why should I use document based database instead of relational database?
...ds of applications or domains where the document based database is more suitable than the relational database?
7 Answers
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How to vertically center a div for all browsers?
I want to center a div vertically with CSS. I don't want tables or JavaScript, but only pure CSS. I found some solutions, but all of them are missing Internet Explorer 6 support.
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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...
MySql - Way to update portion of a string?
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I think this should work:
UPDATE table
SET field = REPLACE(field, 'string', 'anothervalue')
WHERE field LIKE '%string%';
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Row count with PDO
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$sql = "SELECT count(*) FROM `table` WHERE foo = ?";
$result = $con->prepare($sql);
$result->execute([$bar]);
$number_of_rows = $result->fetchColumn();
Not the most elegant way to do it, plus it involves an extra query.
PDO has PDOStatemen...
The Role Manager feature has not been enabled
...thod will run just fine (if you haven't messed elsewhere) and create a few tables in your Database;
Press Ctrl+W+L to open the Server Explorer and you should be able to check in Data Connections > DefaultConnection > Tables the Roles and UsersInRoles tables among the newly created tables!
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