ERROR 2002 (HY000): Can’t connect to local MySQL server through socket ‘/tmp/mysql.sock’

It’s probably because MySQL is installed but not yet running. To verify that it’s running, open up Activity Monitor and under “All Processes”, search and verify you see the process “mysqld”. You can start it by installing “MySQL.prefPane”. Here is the complete tutorial which helped me: http://obscuredclarity.blogspot.in/2009/08/install-mysql-on-mac-os-x.html

Cannot add or update a child row: a foreign key constraint fails

table #1: Field Type Null Key Default Extra UserID int(11) NO PRI NULL auto_increment Password varchar(20) NO Username varchar(25) NO Email varchar(60) NO table #2: Field Type Null Key Default Extra UserID int(11) NO MUL PostID int(11) NO PRI NULL auto_increment Title varchar(50) NO Summary varchar(500) NO Error: com.mysql.jdbc.exceptions.MySQLIntegrityConstraintViolationException: Cannot add or update a child … Read more