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Storing JSON in database vs. having a new column for each key
I am implementing the following model for storing user related data in my table - I have 2 columns - uid (primary key) and a meta column which stores other data about the user in JSON format.
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How to show SQL queries run in the Rails console?
...lain
=> EXPLAIN for: SELECT "categories".* FROM "categories" 0|0|0|SCAN TABLE categories
EXPLAIN for: SELECT "categories_products".* FROM "categories_products" WHERE "categories_products"."category_id" IN (1, 2) 0|0|0|SCAN TABLE categories_products
EXPLAIN for: SELECT "products".* FROM "product...
Worst security hole you've seen? [closed]
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little Bobby tables strikes again... xkcd.com/327
– gbjbaanb
Oct 7 '09 at 12:21
86
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Is the NOLOCK (Sql Server hint) bad practice?
...dated at the same time another process may be selecting data from the same table. If this happens a lot then there's a high probability of deadlocks unless you use a database mode such as READ COMMITED SNAPSHOT.
I have since changed my perspective on the use of NOLOCK after witnessing how it can i...
How to order by with union in SQL?
...olas Carey - when I initially tested using a UNION it was behaving unpredictably as you described, I think the UNION ALL (at least in Oracle) was necessary to order the top SELECT above the bottom. However I've provided an alternate that does guarantee correct ordering and should be database indepe...
SQL command to display history of queries
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For MySQL > 5.1.11 or MariaDB
SET GLOBAL log_output = 'TABLE';
SET GLOBAL general_log = 'ON';
Take a look at the table mysql.general_log
If you want to output to a log file:
SET GLOBAL log_output = "FILE";
SET GLOBAL general_log_file = "/path/to/your/logfile.log"
SET GLOBAL g...
How to convert char to int?
...appens.
A Char, is basically an integer, but with a pointer in the ASCII table. All characters have a corresponding integer value as you can clearly see when trying to parse it.
Pranay has clearly a different character set, thats why HIS code doesnt work.
the only way is
int val = '1' - '0';
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SQL: IF clause within WHERE clause
...tside the SELECT
IF (IsNumeric(@OrderNumber)) = 1
BEGIN
SELECT * FROM Table
WHERE @OrderNumber = OrderNumber
END ELSE BEGIN
SELECT * FROM Table
WHERE OrderNumber LIKE '%' + @OrderNumber
END
3) Using a long string, compose your SQL statement conditionally, and then use EXEC
The 3r...
@Override is not allowed when implementing interface method
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How does the socket API accept() function work?
...g on the Server IP maintains a database (meaning I don't care what kind of table/list/tree/array/magic data structure it uses) of active sockets and listens on the Server Port. When it receives a message (via the server's TCP/IP stack), it checks the Client IP and Port against the database. If the...