So I'm pretty sure I need to do a left join of the table on itself... Something like this: SELECT a.person, COUNT(a.state)/COUNT(b.state) FROM myTable a LEFT JOIN myTable b ON a.job_id=b.job_id AND (s.state='Su
This is done by prepending the table name to the column name. You need not have two different tables to perform a join. Sometimes it is useful to join a table to itself, if you want to compare records in a table to other records in that same table. For example, to find breeding ...
When executed, you should get information both about the duration of the locking process itself, and of the locks on a specific table: Start: Lock->Read test.t2 End: Lock->Read 0 ms Start: Lock->Unlock test.t2 (25743 ms lock duration) End: Lock->Unlock 0 ms Start: Lock->Read te...
ALTER TABLE tommy.girl DROP INDEX ft_email_abcd; 1. 3.使用全文索引 跟普通索引稍有不同 使用全文索引的格式: MATCH (columnName) AGAINST ('string') eg: SELECT * FROM `student` WHERE MATCH(`name`) AGAINST('聪') 当查询多列数据时:
A: Yes. MySQL NDB Cluster itself has the capability to self-heal from failures by automatically restarting failed Data Nodes, without manual intervention. MySQL NDB Cluster Manager extends this functionality by also monitoring and automatically recovering SQL and Management Nodes. This supports a more...
Fixed an issue where aSET PASSWORDstatement was replicated from a MySQL 5.6 master to a MySQL 5.7 slave, or from a MySQL 5.7 master with thelog_builtin_as_identified_by_passwordsystem variable set to ON to a MySQL 5.7 slave, the password hash was itself also hashed before being stored on...
*/ SELECT a.company, a.num, a.stop, b.stop FROM route a JOIN route b ON (a.company=b.company AND a.num=b.num) WHERE a.stop=53 AND b.stop=149; --#6 /* The query shown is similar to the previous one, however by joining two copies of the stops table we can refer to ...
procedure, need to join a temp table to itself. Tried copying the table to use 2 copies, performance was bad. Now using regular tables, but has to serialize operation of stored procedure so that more than one thread doesn't try to use it at the same time. Says will be very bad for...
STRAIGHT_JOIN is not enforced when right-hand table is itself a JOIN Submitted:10 Feb 2011 9:29Modified:10 Feb 2012 3:11 Reporter:Roy LysengEmail Updates: Status:ClosedImpact on me: None Category:MySQL Server: OptimizerSeverity:S3 (Non-critical)...
Choices include, but are not limited to, the following: - Join the table to itself as many times as could possibly be required - Handle the recursion at the application level, e.g. with a PHP loop <-- my preference - Use a Stored Procedure to handle the recursion - Switch to ...