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Create PostgreSQL ROLE (user) if it doesn't exist
... and improved with @Gregory's comment.)
Unlike, for instance, with CREATE TABLE there is no IF NOT EXISTS clause for CREATE ROLE (up to at least pg 12). And you cannot execute dynamic DDL statements in plain SQL.
Your request to "avoid PL/pgSQL" is impossible except by using another PL. The DO sta...
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...
SQL command to display history of queries
...
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';
...
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...
Worst security hole you've seen? [closed]
...
little Bobby tables strikes again... xkcd.com/327
– gbjbaanb
Oct 7 '09 at 12:21
86
...
Comparing date ranges
... |-----| equal start with end of comparison period
If your table has columns called range_end and range_start, here's some simple SQL to retrieve all the matching rows:
SELECT *
FROM periods
WHERE NOT (range_start > @check_period_end
OR range_end < @check_period_s...
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...
@Override is not allowed when implementing interface method
....
Go to Settings [ Ctrl+Alt+S
]
Select Java Compiler
Select module in the table
Change the byte-code version to map what you selected in the previous step for language-level
share
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improve this ...
Detect if an input has text in it using CSS — on a page I am visiting and do not control?
...r spec
The Mozilla/Firefox supported selectors
Cross-browser, CSS3 support table
The :empty selector refers only to child nodes, not input values.
[value=""] does work; but only for the initial state. This is because a node's value attribute (that CSS sees), is not the same as the node's value pr...