ORA-00918: column ambiguously defined in SELECT *

A query’s projection can only have one instance of a given name. As your WHERE clause shows, you have several tables with a column called ID. Because you are selecting * your projection will have several columns called ID. Or it would have were it not for the compiler hurling ORA-00918. The solution is quite simple: you … Read more

Difference between VARCHAR and TEXT in MySQL

TL;DR TEXT fixed max size of 65535 characters (you cannot limit the max size) takes 2 + c bytes of disk space, where c is the length of the stored string. cannot be (fully) part of an index. One would need to specify a prefix length. VARCHAR(M) variable max size of M characters M needs to be between 1 and 65535 takes … Read more

ORA-00918: column ambiguously defined in SELECT *

A query’s projection can only have one instance of a given name. As your WHERE clause shows, you have several tables with a column called ID. Because you are selecting * your projection will have several columns called ID. Or it would have were it not for the compiler hurling ORA-00918. The solution is quite simple: you … Read more

ERROR 2003 (HY000): Can’t connect to MySQL server on ‘127.0.0.1’ (111)

If you are using ubuntu, you have to use the following steps to avoid this error(if there is no replication enabled): run the command vim /etc/mysql/my.cnf comment bind-address = 127.0.0.1 using the # symbol restart your mysql server once. Update In Step 1, if you cannot find bind-address in the my.cnf file, look for it in /etc/mysql/mysql.conf.d/mysqld.cnf file. Update in case of MySQL replication enabled … Read more