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    <p>There is a common theme in the comments here and that is <a href="http://en.wikipedia.org/wiki/Database_normalization" rel="nofollow">normalization</a>. As a rule it is A Bad Thing to represent multiple values as a comma-separated list in a single column.</p> <p>Here is a working example of an alternate DB design that should get you going in the right direction:</p> <pre><code>create table staff ( id int unsigned not null primary key auto_increment, staffName varchar(250), unique key `staffUIdx1` (staffName) ) ENGINE=InnoDB; create table business ( id int unsigned not null primary key auto_increment, businessName varchar(250), unique key `staffUIdx1` (businessName) ) ENGINE=InnoDB; CREATE TABLE staffBusiness ( id int unsigned not null primary key auto_increment, staffId int unsigned not null, businessId int unsigned not null, unique key `staffBusinessUIdx1` (staffId,businessId), CONSTRAINT `fk_staffBusiness_staff1` FOREIGN KEY (`staffId`) REFERENCES `staff` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION, CONSTRAINT `fk_staffBusiness_business1` FOREIGN KEY (`businessId`) REFERENCES `business` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION ) ENGINE=InnoDB; insert into staff (staffName) values ('Bob'); insert into staff (staffName) values ('Bill'); insert into staff (staffName) values ('Paul'); insert into staff (staffName) values ('George'); insert into business (businessName) values ('Business 1'); insert into business (businessName) values ('Business 2'); insert into business (businessName) values ('Business 3'); insert into business (businessName) values ('Business 4'); insert into staffBusiness (staffId,businessId) select s.id,b.id from staff s join business b where s.staffName = 'Bob' and b.businessName in ('Business 1','Business 4'); insert into staffBusiness (staffId,businessId) select s.id,b.id from staff s join business b where s.staffName = 'Bill' and b.businessName in ('Business 2','Business 3'); insert into staffBusiness (staffId,businessId) select s.id,b.id from staff s join business b where s.staffName = 'Paul' and b.businessName in ('Business 3'); </code></pre> <p>...and then the query would look like this:</p> <pre><code>select staffName as Staff,count(sb.id) as Business from staff s left outer join staffBusiness sb on s.id = sb.staffId group by staffName; </code></pre> <p>I've included a 4th member of staff called 'George' to show that a normalized approach allows you to have members of staff with no business too.</p>
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    1. COThank you, this looks incredibly helpful.
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