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SQL: deleting tables with prefix
...r you:
In the MySQL shell or through PHPMyAdmin, use the following query
SELECT CONCAT( 'DROP TABLE ', GROUP_CONCAT(table_name) , ';' )
AS statement FROM information_schema.tables
WHERE table_name LIKE 'myprefix_%';
This will generate a DROP statement which you can than copy and execut...
Simulating group_concat MySQL function in Microsoft SQL Server 2005?
...sy way to do this. Lots of ideas out there, though.
Best one I've found:
SELECT table_name, LEFT(column_names , LEN(column_names )-1) AS column_names
FROM information_schema.columns AS extern
CROSS APPLY
(
SELECT column_name + ','
FROM information_schema.columns AS intern
WHERE extern....
MySQL Results as comma separated list
...
You can use GROUP_CONCAT to perform that, e.g. something like
SELECT p.id, p.name, GROUP_CONCAT(s.name) AS site_list
FROM sites s
INNER JOIN publications p ON(s.id = p.site_id)
GROUP BY p.id, p.name;
share
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How to use GROUP BY to concatenate strings in SQL Server?
...S (1,'B',8)
INSERT INTO #YourTable ([ID],[Name],[Value]) VALUES (2,'C',9)
SELECT
[ID],
STUFF((
SELECT ', ' + [Name] + ':' + CAST([Value] AS VARCHAR(MAX))
FROM #YourTable
WHERE (ID = Results.ID)
FOR XML PATH(''),TYPE).value('(./text())[1]','VARCHAR(MAX)')
,1,2,'') AS NameVa...
Best practices/performance: mixing StringBuilder.append with String.concat
I'm trying to understand what the best practice is and why for concatenating string literals and variables for different cases. For instance, if I have code like this
...
How do I concatenate two strings in C?
...of char that is terminated by the first null character. There is no string concatenation operator in C.
Use strcat to concatenate two strings. You could use the following function to do it:
#include <stdlib.h>
#include <string.h>
char* concat(const char *s1, const char *s2)
{
char...
How do I convert from BLOB to TEXT in MySQL?
...
That's unnecessary. Just use SELECT CONVERT(column USING utf8) FROM..... instead of just SELECT column FROM...
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...
ROW_NUMBER() in MySQL
...asy, but actually it kind of isn't).
I often plump for a null-self-join:
SELECT t0.col3
FROM table AS t0
LEFT JOIN table AS t1 ON t0.col1=t1.col1 AND t0.col2=t1.col2 AND t1.col3>t0.col3
WHERE t1.col1 IS NULL;
“Get the rows in the table for which no other row with matching col1,col2 has a hi...
How should I store GUID in MySQL tables?
...above and when I convert them back using the same methods the guid that is selected is not the one that was inserted. What is transforming the guid? All I've done is copied the code from above.
– vsdev
Dec 17 '15 at 14:53
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MySQL stored procedure vs function, which would I use when?
...d procedures with ordinary SQL, whilst with stored function you can.
e.g. SELECT get_foo(myColumn) FROM mytable is not valid if get_foo() is a procedure, but you can do that if get_foo() is a function. The price is that functions have more limitations than a procedure.
...