JPA - TroubleShooting - Error in Datatypes used in Creating Tables

Question

h1. JPA - TroubleShooting - Error in Datatypes used in Creating Tables
h2. Error Description
The error appears when JPA is trying to automatically
generate tables from Entities. It uses types it shouldn't because they aren't
supported by the Database Engine. If you examine the createDDL.jdbc file you
are going to find not supported data types. You could run the statements that
are listed there directly to your Database Engine and find out that they don`t
run generating syntax errors like the error posted below.
h3. Query example (statement)
CREATE TABLE SEQUENCE (SEQ_NAME VARCHAR(50), SEQ_COUNT NUMBER(19))h3. PostgreSQL Error whent trying to execute the statment
CREATE TABLE SEQUENCE (SEQ_NAME VARCHAR(50),
SEQ_COUNT NUMBER(19))": org.postgresql.util.PSQLException: ERROR: syntax
error near "("
h3. MSSQL 2000 Error when trying to execute the statement:
[CREATE - 0 row(s), 0.578 secs] [Error Code: 2715, SQL State: HY000] [Microsoft][SQLServer 2000 Driver for
JDBC][SQLServer]Column or parameter #1: Cannot find data type NUMBER
h3. FireBird Error when trying to execute the statment
Dynamic SQL Error
SQL error code = -104
Token unknown - line 1, char 62
Statement: CREATE TABLE SEQUENCE (SEQ_NAME VARCHAR(50),
SEQ_COUNT NUMBER(19))
h2. TroubleShooting
Looks like it wants "NUMERIC", not "NUMBER".
[http://www.postgresql.org/docs/8.1/interactive/datatype.html#DATATYPE-NUMERIC]
I had this problem using Firebird. I found out it had to do
with the database jdbc driver. I tried using a different database engine, like
Microsoft SQL Server 2000 with the corresponding driver and it worked as it
should. I suspect the JDBC driver has to supply in some way the datatypes it
supports to JPA TopLink Library.
Edited by: juanemc2 on Apr 1, 2008 7:39 AM

Answer 1

In Hibernate you can supply the "dialect" to use for SQL generation. I assume TopLink to have a similar functionality.
This is not a generic JPA issue, but rather something with the specific implementation you're using.
Or rather it is a generic SQL issue, caused by different database engines using slightly (or not so slightly) different SQL syntax which causes problems when generating SQL automatically.