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MySQL, Check if a column exists in a table with SQL
I am trying to write a query that will check if a specific table in MySQL has a specific column, and if not — create it. Otherwise do nothing. This is really an easy procedure in any enterprise-class database, yet MySQL seems to be an exception.
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“Incorrect string value” when trying to insert UTF-8 into MySQL via JDBC?
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MySQL's utf8 permits only the Unicode characters that can be represented with 3 bytes in UTF-8. Here you have a character that needs 4 bytes: \xF0\x90\x8D\x83 (U+10343 GOTHIC LETTER SAUIL).
If you have MySQL 5.5 or later you...
Maximum number of records in a MySQL database table
What is the upper limit of records for MySQL database table. I'm wondering about autoincrement field. What would happen if I add milions of records? How to handle this kind of situations?
Thx!
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【BLE技术内幕】BLE技术揭秘 - 创客硬件开发 - 清泛IT论坛，有思想、有深度
...个时间点把数据包发送出去，怎么保证数据的完整性，ACK如何接收，如何进行重传，以及如何对链路进行管理和控制等等。LL层只负责把数据发出去或者收回来，对数据进行怎样的解析则交给上面的GAP或者ATTHost Controller Interface，...
How do you set a default value for a MySQL Datetime column?
How do you set a default value for a MySQL Datetime column?
25 Answers
25
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What is the best collation to use for MySQL with PHP? [closed]
I'm wondering if there is a "best" choice for collation in MySQL for a general website where you aren't 100% sure of what will be entered? I understand that all the encodings should be the same, such as MySQL, Apache, the HTML and anything inside PHP.
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PHP + MySQL transactions examples
I really haven't found normal example of PHP file where MySQL transactions are being used. Can you show me simple example of that?
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Equivalent of varchar(max) in MySQL?
What is the equivalent of varchar(max) in MySQL?
6 Answers
6
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Display open transactions in MySQL
...transactions and commit or cancel them?
There is no open transaction, MySQL will rollback the transaction upon disconnect.
You cannot commit the transaction (IFAIK).
You display threads using
SHOW FULL PROCESSLIST
See: http://dev.mysql.com/doc/refman/5.1/en/thread-information.html
It...
How to get the next auto-increment id in mysql
How to get the next id in mysql to insert it in the table
19 Answers
19
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