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com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
...
So, you have a
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
java.net.ConnectException: Connection refused
I'm quoting from this answer which also contains a step-by-step MySQL+JDBC tutorial:
If yo...
App Inventor 2 人脸识别App开发 - 第三方API接入的通用方法 · App Inventor 2 中文网
...建一个应用以获得API调用时必要的api_key及api_secret。
如何理解api_key及api_secret：可以类比为 API Key是用户ID（用于标识用户），Secret Key是密码（用于鉴权）。“你需要两个不同的密钥，一个告诉他们你是谁，另一个证明你就是...
Suppress warning messages using mysql from within Terminal, but password written in bash script
When I tried running the following command on MySQL from within Terminal:
25 Answers
2...
error: 'Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)' — Miss
...roblem started off with me not being able to log in as root any more on my mysql install. I was attempting to run mysql without passwords turned on... but whenever I ran the command
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How to import a single table in to mysql database using command line
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Linux :
In command line
mysql -u username -p databasename < path/example.sql
put your table in example.sql
Import / Export for single table:
Export table schema
mysqldump -u username -p databasename tableName > path/example.sql
This ...
Abusing the algebra of algebraic data types - why does this work?
...gard that for the sake of simplicity.
A few initial points:
Note that "union" is probably not the best term for A+B here--that's specifically a disjoint union of the two types, because the two sides are distinguished even if their types are the same. For what it's worth, the more common term is ...
How to take backup of a single table in a MySQL database?
By default, mysqldump takes the backup of an entire database. I need to backup a single table in MySQL. Is it possible? How do I restore it?
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Create new user in MySQL and give it full access to one database
I want to create a new user in MySQL and give it full access only to one database, say dbTest , that I create with a command like create database dbTest; . What would be the MySQL commands to do that?
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MySql Table Insert if not exist otherwise update
... re-written using the proper INSERT ... ON DUPLICATE KEY UPDATE syntax for MySQL:
INSERT INTO AggregatedData (datenum,Timestamp)
VALUES ("734152.979166667","2010-01-14 23:30:00.000")
ON DUPLICATE KEY UPDATE
Timestamp=VALUES(Timestamp)
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Possible to do a MySQL foreign key to one of two possible tables?
...ut logical XOR is not standard SQL and is not supported by all SQL brands. MySQL has it, but PostgreSQL does not. Oracle has it, but Microsoft does not until 2016. And so on.
– Bill Karwin
Aug 19 '15 at 15:09
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