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Getting a map() to return a list in Python 3.x
...You can wrap the above in list if you really need a list of the individual characters, but since str is already an iterable of its own characters, the only reason you'd do so is if you need mutability.
– ShadowRanger
Jul 1 '16 at 1:52
...
How do I convert an integer to string as part of a PostgreSQL query?
...o 15 digits, you'll meed to cast to an 64 bit (8-byte) integer. Try this:
SELECT * FROM table
WHERE myint = mytext::int8
The :: cast operator is historical but convenient. Postgres also conforms to the SQL standard syntax
myint = cast ( mytext as int8)
If you have literal text you want to c...
add column to mysql table if it does not exist
...rade_database_1_0_to_2_0()
BEGIN
-- rename a table safely
IF NOT EXISTS( (SELECT * FROM information_schema.COLUMNS WHERE TABLE_SCHEMA=DATABASE()
AND TABLE_NAME='my_old_table_name') ) THEN
RENAME TABLE
my_old_table_name TO my_new_table_name,
END IF;
-- add a column safely
IF NO...
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
...
Parse config files, environment, and command-line arguments, to get a single collection of options
...because users will only have to learn one syntax.) Setting fromfile_prefix_chars to, for example, @, makes it so that,
my_prog --foo=bar
is equivalent to
my_prog @baz.conf
if @baz.conf is,
--foo
bar
You can even have your code look for foo.conf automatically by modifying argv
if os.path.e...
Unsigned keyword in C++
...ng -> signed long
signed long
unsigned long
Be careful of char:
char (is signed or unsigned depending on the implmentation)
signed char
unsigned char
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ZeroMQ实例-使用ZMQ(ZeroMQ)进行局域网内网络通信 - C/C++ - 清泛网 - 专注C/C++及内核技术
...q的头文件
#include <zmq.h>
#include "stdio.h"
int main(int argc, char * argv[])
{
void * pCtx = NULL;
void * pSock = NULL;
const char * pAddr = "tcp://*:7766";
//创建context，zmq的socket 需要在context上进行创建
if((pCtx = zmq_ctx_new()) == NULL)
...
SQLAlchemy IN clause
...3,456))).all()
edit: Without the ORM, it would be
session.execute(
select(
[MyUserTable.c.id, MyUserTable.c.name],
MyUserTable.c.id.in_((123, 456))
)
).fetchall()
select() takes two parameters, the first one is a list of fields to retrieve, the second one is the where ...
mysql_fetch_array()/mysql_fetch_assoc()/mysql_fetch_row()/mysql_num_rows etc… expects parameter 1 to
I am trying to select data from a MySQL table, but I get one of the following error messages:
31 Answers
...
How can I custom-format the Autocomplete plug-in results?
...g the jQuery UI Autocomplete plug-in . Is there a way to highlight search character sequence in drop-down results?
13 Answ...