大约有 7,000 项符合查询结果（耗时：0.0153秒） [XML]
MySQL Update Inner Join tables query
I have no idea what the problem is. Using MySQL 5.0 I get a compile error when attempting to run the following MySQL update query:
...
MySQL: @variable vs. variable. What's the difference?
...
MySQL has a concept of user-defined variables.
They are loosely typed variables that may be initialized somewhere in a session and keep their value until the session ends.
They are prepended with an @ sign, like this: @var
Yo...
How to Get True Size of MySQL Database?
I would like to know how much space does my MySQL database use, in order to select a web host.
I found the command SHOW TABLE STATUS LIKE 'table_name' so when I do the query, I get something like this:
...
MFC中ComboBox控件的使用 - C/C++ - 清泛网 - 专注C/C++及内核技术
MFC中ComboBox控件的使用一、如何添加 删除Combo Box内容1，在ComboBox控件属性的Data标签里面添加，一行表示ComboBox下拉列表中的一行。换行用ctrl+回车。2，在程...一、如何添加/删除Combo Box内容
1，在ComboBox控件属性的Data标签里面添...
MySQL load NULL values from CSV data
...
MySQL manual says:
When reading data with LOAD DATA
INFILE, empty or missing columns are
updated with ''. If you want a NULL
value in a column, you should use \N
in the data file. The literal word
“NULL” ma...
30岁之后，程序员该向什么方向发展？ - 杂谈 - 清泛网 - 专注C/C++及内核技术
...怕什么？
QA&3. 专注coding还是走向管理，程序员职场规划如何抉择？
严清：
我是选择了偏向 coding，但还是要做一定管理，我要带领小伙伴们提升技术，要推进公司的技术水平，这些还是需要管理的。可以说是管理技术不管产...
Error 1046 No database Selected, how to resolve?
...
You need to tell MySQL which database to use:
USE database_name;
before you create a table.
In case the database does not exist, you need to create it as:
CREATE DATABASE database_name;
followed by:
USE database_name;
...
What's the difference between utf8_general_ci and utf8_unicode_ci?
...ncoding. The differences are in how text is sorted and compared.
Note: In MySQL you have to use utf8mb4 rather than utf8. Confusingly, utf8 is a flawed UTF-8 implementation from early MySQL versions which remains only for backward compatibility. The fixed version was given the name utf8mb4.
Note: N...
Using column alias in WHERE clause of MySQL query produces an error
...is
executed, the column value may not yet
be determined.
Copied from MySQL documentation
As pointed in the comments, using HAVING instead may do the work. Make sure to give a read at this WHERE vs HAVING though.
share...
What MySQL data type should be used for Latitude/Longitude with 8 decimal places?
...
DECIMAL is the MySQL data-type for exact arithmetic. Unlike FLOAT its precision is fixed for any size of number, so by using it instead of FLOAT you might avoid precision errors when doing some calculations. If you were just storing and ret...