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Types in MySQL: BigInt(20) vs Int(20)
...E TABLE foo ( bar INT(20) ZEROFILL );
INSERT INTO foo (bar) VALUES (1234);
SELECT bar from foo;
+----------------------+
| bar |
+----------------------+
| 00000000000000001234 |
+----------------------+
It's a common source of confusion for MySQL users to see INT(20) and assume ...
Count characters in textarea
I want to count characters in a textarea, so I just made:
21 Answers
21
...
Extract date (yyyy/mm/dd) from a timestamp in PostgreSQL
... to a date by suffixing it with ::date. Here, in psql, is a timestamp:
# select '2010-01-01 12:00:00'::timestamp;
timestamp
---------------------
2010-01-01 12:00:00
Now we'll cast it to a date:
wconrad=# select '2010-01-01 12:00:00'::timestamp::date;
date
------------
201...
Concatenate multiple result rows of one column into one, group by another column [duplicate]
...Simpler with the aggregate function string_agg() (Postgres 9.0 or later):
SELECT movie, string_agg(actor, ', ') AS actor_list
FROM tbl
GROUP BY 1;
The 1 in GROUP BY 1 is a positional reference and a shortcut for GROUP BY movie in this case.
string_agg() expects data type text as input. Other ...
How to handle Objective-C protocols that contain properties?
...hInteger:(factor*amount)];
}
// <<
@end
int main(int argc, const char * argv[])
{
@autoreleasepool {
Person *duncan=[[Person alloc]initConforming];
duncan.firstname=@"Duncan";
duncan.lastname=@"Smith";
[Viewer printLargeDescription:duncan];
S...
Program only crashes as release build — how to debug?
...sh do an Attach To Process (Tools menu on Visual Studio).
After the crash, select the option to launch debugger.
When asked to point to PDB files, browse to find them. If the PDB's were put in the same output folder as your E
How to make an OpenGL rendering context with transparent background?
... 0);
assert(hbmpDIB);
assert(bmp_cnt);
if(hbmpDIB)
SelectObject(pdcDIB, hbmpDIB);
}
BOOL CreateHGLRC()
{
DWORD dwFlags = PFD_SUPPORT_OPENGL | PFD_DRAW_TO_BITMAP;
PIXELFORMATDESCRIPTOR pfd ;
memset(&pfd,0, sizeof(PIXELFORMATDESCRIPTOR)) ;
pfd.nSize = size...
Use '=' or LIKE to compare strings in SQL?
...
To see the performance difference, try this:
SELECT count(*)
FROM master..sysobjects as A
JOIN tempdb..sysobjects as B
on A.name = B.name
SELECT count(*)
FROM master..sysobjects as A
JOIN tempdb..sysobjects as B
on A.name LIKE B.name
Comparing strings with '=' is muc...
Difference between one-to-many and many-to-one relationship
... Bar references Foo
Not the other way around
CREATE TABLE Foo (
Foo CHAR(10) NOT NULL, -- primary key
Name CHAR(30) NOT NULL
CONSTRAINT PK -- constraint name
PRIMARY KEY (Foo) -- pk
)
CREATE TABLE Bar (
Bar CHAR(10) NOT NULL, -- primary key
...
MySQL Conditional Insert
...
If your DBMS does not impose limitations on which table you select from when you execute an insert, try:
INSERT INTO x_table(instance, user, item)
SELECT 919191, 123, 456
FROM dual
WHERE NOT EXISTS (SELECT * FROM x_table
WHERE user = ...