How to Find Errors in a Diagram

The Check Diagram tool of the Database Designer for MySQL allows you to check your database diagram for most typical errors and defects. The result of the check goes in a well structured form, using which you can easily bring your diagram to correspondence with the common standards of database modeling.

To open the Check Diagram dialog use the Check Diagram (

) item on Diagram tab of the Ribbon or press F4.

Use the Select diagram drop-down list to select the diagram from the list of currently opened diagrams. Current opened diagram is selected by default.

The tree list below allows you to select what warnings and errors should be taken into account during the check. All warnings and errors are divided into categories, which correspond to the diagram objects. Remove selection from the warning/error or from the whole category to exclude it from the check.

Error level	Objects to be verified	Comment
Table
Error	Table Name Uniqueness	checks the diagram for the uniqueness of each table name within a diagram
Warning	Table Name Max Length	MySQL allows only 64 characters in table names and cuts names if they are longer than this
Error	Column Definition	checks if each table within the diagram owns at least one column
Warning	Index Definition	checks if each table within the diagram owns at least one index
Warning	Primary Key Definition	checks if a primary key is defined for each table within the diagram
Warning	Reference Definition	checks if each table within the diagram is linked with other tables
Error	Auto-increment columns	checks if each table within the diagram has no more than one auto-increment column, as otherwise MySQL will not allow such table to be created
Error	Trigger Times and Events	checks if every trigger in each table within diagram has unique Time and Event combination
Table Columns
Error	Column Name Uniqueness	checks diagram tables for the uniqueness of each column name within the table
Warning	Column Name Max Length	MySQL allows only 64 characters in column names and cuts names if they are longer than this
Warning	Auto-increment Column Definition	checks if each auto-increment column within a table is a part of a primary key
Table Indexes
Error	Index Name Uniqueness	checks diagram tables for the uniqueness of each index name within the table
Warning	Index Name Max Length	MySQL allows only 64 characters in index names and cuts names if they are longer than this
Warning	Duplicate Index Column	checks if each table column is indexed only once
References
Warning	Reference Table Type	checks if both linked tables use storage engine that supports references (for example InnoDB or Falcon) for each diagram reference
Error	Reference Column Data Types	checks whether the linked columns are of the same data type for each diagram reference
Error	Reference Column does not exists	checks an existence of referenced column in parent table for each diagram reference
Error	Reference Name uniqueness	checks diagram references for uniqueness of each reference name
Error	Check "SET NULL" FK-action for NOT NULL column	MySQL does not allow SET NULL action for foreign keys that reference column marked with NOT NULL attribute
Domains
Error	Domain Name Uniqueness	checks diagram for the uniqueness of each domain name within a diagram
Stored Routine
Error	Stored Routine Name Uniqueness	checks diagram stored procedures and functions for the uniqueness of name within a schema
Warning	Stored Routine Name Max Length	MySQL allows only 64 characters in stored routine names and cuts names if they are longer than this
Views
Error	View Name Uniqueness	checks diagram stored procedures and functions for the uniqueness of name within a schema
Warning	View Name Max Length	MySQL allows only 63 characters in stored routine names and cuts names if they are longer than this
Error	View was created on a not existing table	checks existence of tables, which are used in the view
Error	View was created on a not existing column	check existence of table columns, which are used in the view

After you click OK the check process will be displayed within the Output window and the result of the check will be displayed within the Result window in the same categorized view as described above.

Double-click on a warning or an error in the list opens the editor window for the appropriate object (Table Editor, View Editor, Domain Manager and so on).

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How to... > How to Find Errors in a Diagram