MySQL - Read For Learn

MySQL error code: 1175 during UPDATE in MySQL Workbench

I found the answer. The problem was that I have to precede the table name with the schema name. i.e, the command should be: Thanks all.

Usage of MySQL’s “IF EXISTS”

You cannot use IF control block OUTSIDE of functions. So that affects both of your queries. Turn the EXISTS clause into a subquery instead within an IF function In fact, booleans are returned as 1 or 0

SELECT * FROM multiple tables. MySQL

What you do here is called a JOIN (although you do it implicitly because you select from multiple tables). This means, if you didn’t put any conditions in your WHERE clause, you had all combinations of those tables. Only with your condition you restrict your join to those rows where the drink id matches. But there are still X … Read more

Mysql command not found in OS X 10.7

This is the problem with your $PATH: /usr/local//usr/local/mysql/bin/private/var/mysql/private/var/mysql/bin. $PATH is where the shell searches for command files. Folders to search in need to be separated with a colon. And so you want /usr/local/mysql/bin/ in your path but instead it searches in /usr/local//usr/local/mysql/bin/private/var/mysql/private/var/mysql/bin, which probably doesn’t exist. Instead you want ${PATH}:/usr/local/mysql/bin. So do export PATH=${PATH}:/usr/local/mysql/bin. If you want this to be run … Read more

mysql update multiple columns with same now()

Found a solution: I found this in MySQL Docs and after a few tests it works: the following statement sets col2 to the current (updated) col1 value, not the original col1 value. The result is that col1 and col2 have the same value. This behavior differs from standard SQL. UPDATE t1 SET col1 = col1 + 1, … Read more

mysqladmin: connect to server at ‘localhost’ failed

Short version: If your MySQL user root needs a password to connect, it might be a good idea to have mysqladmin provide that password 😉 Longer version: Your MySQL user root seems to need a password to connect setting the mysql root password new But mysqladmin tries to connect without a password ‘Access denied for user ‘root’@’localhost’ (using password: NO)’ And mysqladmin does that because you’re not … Read more

Find all tables containing column with specified name – MS SQL Server

Is it possible to query for table names which contain columns being ?

difference between primary key and unique key

Primary Key: There can only be one primary key constraint in a table In some DBMS it cannot be NULL – e.g. MySQL adds NOT NULL Primary Key is a unique key identifier of the record Unique Key: Can be more than one unique key in one table Unique key can have NULL values It can be a candidate key … Read more

Host ‘xxx.xx.xxx.xxx’ is not allowed to connect to this MySQL server

Possibly a security precaution. You could try adding a new administrator account: Although as Pascal and others have noted it’s not a great idea to have a user with this kind of access open to any IP. If you need an administrative user, use root, and leave it on localhost. For any other action specify … Read more

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