SQL query to get the employee name and their manager name from the same table
You can self-join the table to get the manager’s name from his ID:
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MySQL Error: : ‘Access denied for user ‘root’@’localhost’
Open and edit /etc/my.cnf or /etc/mysql/my.cnf, depending on your distribution. Add skip-grant-tables under [mysqld] Restart MySQL You should be able to log in to MySQL now using the below command mysql -u root -p Run mysql> flush privileges; Set new password by ALTER USER ‘root’@’localhost’ IDENTIFIED BY ‘NewPassword’; Go back to /etc/my.cnf and remove/comment skip-grant-tables Restart MySQL Now you will be able to login with the … Read more
QL Error: ORA-00933: SQL command not properly ended
Oracle does not allow joining tables in an UPDATE statement. You need to rewrite your statement with a co-related sub-select Something like this: For a complete description on the (valid) syntax of the UPDATE statement, please read the manual: http://docs.oracle.com/cd/E11882_01/server.112/e26088/statements_10008.htm#i2067715
MySQL “CREATE TABLE IF NOT EXISTS” -> Error 1050
Works fine for me in 5.0.27 I just get a warning (not an error) that the table exists;
When should I use CROSS APPLY over INNER JOIN?
Can anyone give me a good example of when CROSS APPLY makes a difference in those cases where INNER JOIN will work as well? See the article in my blog for detailed performance comparison: INNER JOIN vs. CROSS APPLY CROSS APPLY works better on things that have no simple JOIN condition. This one selects 3 … Read more
Conversion failed when converting date and/or time from character string while inserting datetime
There are many formats supported by SQL Server – see the MSDN Books Online on CAST and CONVERT. Most of those formats are dependent on what settings you have – therefore, these settings might work some times – and sometimes not. The way to solve this is to use the (slightly adapted) ISO-8601 date format that is supported by SQL … Read more
SQL SELECT WHERE field contains words
Rather slow, but working method to include any of words: If you need all words to be present, use this: If you want something faster, you need to look into full text search, and this is very specific for each database type.
MySQL – Operand should contain 1 column(s)
Your subquery is selecting two columns, while you are using it to project one column (as part of the outer SELECT clause). You can only select one column from such a query in this context. Consider joining to the users table instead; this will give you more flexibility when selecting what columns you want from … Read more
What’s the difference between INNER JOIN, LEFT JOIN, RIGHT JOIN and FULL JOIN? [duplicate]
Reading this original article on The Code Project will help you a lot: Visual Representation of SQL Joins. Also check this post: SQL SERVER – Better Performance – LEFT JOIN or NOT IN?. Find original one at: Difference between JOIN and OUTER JOIN in MySQL.