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Best practices for SQL varchar column length [closed]
... table's varchar column. But I could not find any reference for that.
For MySQL the manual says "In most cases, ALTER TABLE makes a temporary copy of the original table". And my own tests confirm that: running an ALTER TABLE on a table with 1.2 million rows (the same as in my test with Postgres) to...
PHP的函数前加上“@”的作用 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...供的错误信息屏蔽的专用符号。比如在一个函数前使用@@mysql_query 不会出现Warning，而原来mysql_query 在遇到错误时会在页面上访提示Warning。@是PHP提供的错误信息屏蔽的专用符号。
比如在一个函数前使用@
@mysql_query 不会出现Warning...
Curses library not found. Please install appropriate package - 更多...
Curses library not found. Please install appropriate packageCentOS安装MySql报错：-- Could NOT find Curses (missing: CURSES_LIBRARY CURSES_INCLUDE_PATH)CMake Error at cmake readli...CentOS安装MySql报错：
-- Could NOT find Curses (missing: CURSES_LIBRARY CURSES_INCLUDE_PATH)
CMake Err...
Count number of records returned by group by
... other databases to test it out on, and I'm not so familiar with T-Sql and MySQL syntax.
Also, I'm not entirely sure whether it's more efficient in the parser to do it this way, or whether everyone else's solution of nesting the select statement is better. But I find this one to be more elegant fr...
LIMIT 10..20 in SQL Server
... not part of standard SQL. It's supported as a vendor extension to SQL by MySQL, PostgreSQL, and SQLite.
Other brands of database may have similar features (e.g. TOP in Microsoft SQL Server), but these don't always work identically.
It's hard to use TOP in Microsoft SQL Server to mimic the LIMI...
Making Python loggers output all messages to stdout in addition to log file
...tput is handled by the handlers; just add a logging.StreamHandler() to the root logger.
Here's an example configuring a stream handler (using stdout instead of the default stderr) and adding it to the root logger:
import logging
import sys
root = logging.getLogger()
root.setLevel(logging.DEBUG)
...
Django rest framework nested self-referential objects
...ution works but the count output of my serializer is wrong. It only counts root nodes. Any ideas? It's the same with djangorestframework-recursive.
– Lucas Veiga
May 3 '17 at 1:29
...
Using GPU from a docker container?
...ocker
Find your nvidia devices
ls -la /dev | grep nvidia
crw-rw-rw- 1 root root 195, 0 Oct 25 19:37 nvidia0
crw-rw-rw- 1 root root 195, 255 Oct 25 19:37 nvidiactl
crw-rw-rw- 1 root root 251, 0 Oct 25 19:37 nvidia-uvm
Run Docker container with nvidia driver pre-installed
I've ...
Count the number of occurrences of a string in a VARCHAR field?
...test 0
test4 valuevaluevaluevaluevalue 5
I don't have MySQL install, but goggled to find the Equivalent of LEN is LENGTH while REPLACE is same.
So the equivalent query in MySql should be
SELECT TITLE,DESCRIPTION, (LENGTH(DESCRIPTION) - LENGTH(REPLACE(DESCRIPTION, 'value', ''))...
How do I create a parameterized SQL query? Why Should I?
...lass to start with SQL and you can build from there and add to the class.
MySQL
Public Class mysql
'Connection string for mysql
Public SQLSource As String = "Server=123.456.789.123;userid=someuser;password=somesecurepassword;database=somedefaultdatabase;"
'database connection classes...