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From:Ledina Hido Date:October 19 2005 2:34pm
Subject:Checking Multiplicity Constraints and Retrieving Details from Error Messages
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As part of my 4th Year Group Design Project, I am required to build a  
database system that will validate and then store the data. As such I  
am currently investigating different DB, to choose the most suitable  
one. I like many features of MySQL but there are a couple of things I  
am not very clear about that I would need for the project.

First of all, is there any way of limiting the number of rows in a  
table, referencing to the same element of another table? For example,  
force a manager not to have more than 10 employees under his control.  
In a way this can be seen as checking the multiplicity of the  
relation between the two tables. I know one way would be using  
triggers, but I was wondering if there was a way of specifying this  
when the table is constructed.

Second, is there any way of getting more details out of an error  
message? So for example, when doing a bulk upload to the database,  
rather than just getting "Cannot add or update a child row: a foreign  
key constraint fails" I would like to know which particular insert  
statement (out of the 1000 I have) caused the problem, or which field  
in this statement broke the constraint.

Any help would be much appreciated.

Ledina
Thread
Checking Multiplicity Constraints and Retrieving Details from Error MessagesLedina Hido19 Oct
  • Re: Checking Multiplicity Constraints and Retrieving Details from Error MessagesMartijn Tonies19 Oct
    • Re: Checking Multiplicity Constraints and Retrieving Details from Error MessagesLedina Hido19 Oct
    • Re: Checking Multiplicity Constraints and Retrieving Details from Error MessagesJochem van Dieten19 Oct
  • Re: Checking Multiplicity Constraints and Retrieving Details from Error MessagesMartijn Tonies19 Oct
    • Re: Checking Multiplicity Constraints and Retrieving Details from Error MessagesJochem van Dieten19 Oct
      • Re: Checking Multiplicity Constraints and Retrieving Details from Error MessagesLedina Hido19 Oct
  • Re: Checking Multiplicity Constraints and Retrieving Details from Error MessagesMartijn Tonies20 Oct
    • Re: Checking Multiplicity Constraints and Retrieving Details from Error MessagesJochem van Dieten20 Oct
  • Re: Checking Multiplicity Constraints and Retrieving Details from Error MessagesMartijn Tonies20 Oct
  • Re: Checking Multiplicity Constraints and Retrieving Details from Error MessagesHarald Fuchs20 Oct
    • Re: Checking Multiplicity Constraints and Retrieving Details from Error MessagesJochem van Dieten20 Oct