6.1 Why are
there no arcs between the tables in the references
graph?
The graph illustrates the relationships between tables in
databases supporting referential integrity (also called
primary and foreign key mappings). The graph displays no arcs
between tables if the database do no support primary/foreign
key mapping or if mappings has not been defined. Databases
such as Oracle, Sybase, DB2 and Cloudscape normally supports
referential integrity.
6.2 What is this
variable stuff?
The variable management in DbVisualizer is a technique that
is used internally in DbVisualizer but can also be used to
build dynamic custom SQL statements. A variable typically
looks something like $$FullName||text$$ and are
search for in the SQL Commander only. A variable must begin
and end with the character identified by the "Variable
Identifier" property ("$$" in the example above). During
execute of a SQL statement in SQL Commander will DbVisualizer
search for variables and display a dialog with the name of the
variable and an input field. Selecting "Execute" in the
substitution dialog will replace the entered value for each
variable in the original statement.
The syntax of a
variable is the following:
variableName [|
defaultValue [| type [| format]]] (The variable
delimiter "|" can be changed in tool properties).
- variableName
Required. Is the name that will
appear in the substitution dialog. If several variables have
the same name then the substitution dialog will show only
one and the entered value will be applied to all of that
name.
- defaultValue
The default value that will
appear in the substitution dialog
- type
The type of variable. text or int. This
tells DbVisualizer if the value shall be enclosed within
apostrophes or not. If no type is specified then it is
considered an int.
- format
Currently only used to indicate whether
the column that is represented by the variable is a primary
key or not (pk). This is extracted by DbVisualizer when any
of the "Data" tab pop-up menu choices is selected.
6.3 Only alpha-numeric keys work in
the SQL Commander
Turn off the "NUM LOCK".
6.4 What is the
difference between a database procedure and a
function?
Procedures can not return any results while Functions must
return results.
6.5 Viewing a table with a
mixed case name in Oracle do not work
(This problem do also appear for other database then
Oracle. We use it here as an example).
Oracle normally uppercase all object names like table name,
index, synonym, column names, etc. It is however possible to
create a table like:
create table myschema."MyTable"
This will cause Oracle to create the table
exactly as specified. To select from this table you must enter
select * from myschema."MyTable"
The "Data" and "Rows" tab in DbVisualizer
uses the SQL select statements as specified in tool
properties.
Workaround:
Open Tool Properties and modify the
SQL Select All to the following:
select
* from $$schema$$$$schemaseparator$$"$$table$$"
Modify the SQL Select Count to: select
count(*) from $$schema$$$$schemaseparator$$"$$table$$"
6.6 I get
java.lang.AbstractMethodError in the "Data" and
"SQL Commander" tabs
DbVisualizer requires a Java 2 (JDBC 2.0) compliant JDBC
driver in order to work properly. The following error messages
(in the debug window) are typically related to when using a
driver that is not Java 2 compatible.
Exception occurred during event dispatching:
java.lang.AbstractMethodError
at se.pureit.dbvis.Selector.getValue(Selector.java:201)
...
Exception occured during event dispatching:
java.lang.AbstractMethodError:
oracle/jdbc/driver/OracleResultSet.getBigDecimal
...
java.sql.SQLException: Unsupported feature at
oracle.jdbc.dbaccess.DBError.check_error(DBError.java:479) at
oracle.jdbc.driver.OracleResultSet.getBigDecimal(
OracleResultSet.java:866)
...
If you get any of these errors
then get a Java 2 compliant
JDBC
driver and try again.
6.7 My Synonyms or Triggers are not
displayed in the Database Objects tree
DbVisualizer relies on the meta data information provided
by the JDBC specification. The spec do currently not support
synonyms or triggers and so is DbVisualizer unable to
visualize them.
6.8 Why can't I see the
code for my stored procedures and functions?
DbVisualizer relies on the meta data information provided
by the JDBC specification. The spec do currently not support
fetching the source code for stored procedures or functions
and so is DbVisualizer unable to visualize them.
6.9 I press "Stop" and nothing
happens
Pressing "Stop" while a SQL statement is executing will
only interrupt the execution if DbVisualizer have the current
control of the execution. I.e if the database is currently
executing the statement then DbVisualizer will wait to
interrupt the processing until the database is finished
executing the statement. The reason for this is that the JDBC
"cancel" call might cause some JDBC drivers to make the
application freeze or other strange errors.
6.10 Can a multi statement SQL script access several
database connections and/or databases?
No! The multi SQL statement execution facility in
DbVisualizer Personal can only access database objects in one
specific database connection.
6.11 My XP box suddenly freeze!
Several users have reported that their XP (and also
Win2000) machines freeze when using DbVisualizer. ("The only
workaround is to power off the box!")
The root of this
problem is pre Java 1.4.1_02 versions in combination with some
graphics cards. Please read more in the bug report 4713003
at http://www.sun.com for possible workarounds.
The preferred solution to this problem is to upgrade the
Java VM to JRE/JDK 1.4.1_03 from Sun.
If upgrading the JVM is not an option then the workaround
suggestions in the bug report tells how to pass properties to
the Java VM. For DbVisualizer you must add these to the
dbvis.lax file in the following format:
sun.java2d.noddraw=true
sun.java2d.d3d=false
6.12 Debugging DbVisualizer
Do the following to enable more detailed debug output from
DbVisualizer:
- Open File->Tool Properties
- Select the Debug category
- Set Debug Level to Debug
- Set Detail Level to Full
- Press Ok in the Tool Properties window
- Open the View->Debug Window
Now perform the operation in DbVisualizer you want detailed
debug information for.
