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Swapping column values in MySQL
I have a MySQL table with coordinates, the column names are X and Y. Now I want to swap the column values in this table, so that X becomes Y and Y becomes X. The most apparent solution would be renaming the columns, but I don't want to make structure changes since I don't necessarily have permission...
贝因美创始人谈连续创业 谢宏：蓝海策略下的未来赢家 - 资讯 - 清泛网 - 专...
...程，阐释成功创业创新的关键点。
“现在主要精力在于如何帮助贝因美转型升级，对于我个人而言，原来是创业家，企业家，现在则是转为帮助他们去创业”，谢宏在接受《每日经济新闻》(以下简称NBD)记者专访时透露，8月28...
XAMPP - MySQL shutdown unexpectedly
When I open XAMPP and click start MySQL button and it gives me an error.
I had started it just before, but now it isn't working.
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Find most frequent value in SQL column
...+1 for using standard SQL that will work in any database (whereas LIMIT is MySQL specific, TOP is SQL Server specific).
– Dylan Smith
Jul 20 '18 at 14:46
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SQL command to display history of queries
I would like to display my executed sql command history in my MYSQL Query Browser. What is the sql statement for displaying history?
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How do I calculate square root in Python?
...valuate to 0.
And for the record, the preferred way to calculate a square root is this:
import math
math.sqrt(x)
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PDO MySQL: Use PDO::ATTR_EMULATE_PREPARES or not?
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To answer your concerns:
MySQL >= 5.1.17 (or >= 5.1.21 for the PREPARE and EXECUTE statements) can use prepared statements in the query cache. So your version of MySQL+PHP can use prepared statements with the query cache. However, make careful ...
CHECK constraint in MySQL is not working
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MySQL 8.0.16 is the first version that supports CHECK constraints.
Read https://dev.mysql.com/doc/refman/8.0/en/create-table-check-constraints.html
If you use MySQL 8.0.15 or earlier, the MySQL Reference Manual says:
T...
Efficient SQL test query or validation query that will work across all (or most) databases
...it of research along with help from some of the answers here:
SELECT 1
H2
MySQL
Microsoft SQL Server (according to NimChimpsky)
PostgreSQL
SQLite
SELECT 1 FROM DUAL
Oracle
SELECT 1 FROM any_existing_table WHERE 1=0
or
SELECT 1 FROM INFORMATION_SCHEMA.SYSTEM_USERS
or
CALL NOW()
HSQLDB (tested ...
pip install mysql-python fails with EnvironmentError: mysql_config not found
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It seems mysql_config is missing on your system or the installer could not find it.
Be sure mysql_config is really installed.
For example on Debian/Ubuntu you must install the package:
sudo apt-get install libmysqlclient-dev
Maybe...