using grails with legacy database - oracle

Question

I faced with problem of using Grails with legacy Oracle database. I have legacy table TARGETTYPES with primary key text column TARGETTYPECODE:
CREATE TABLE "TMS"."TARGETTYPES"
( "TARGETTYPECODE" VARCHAR2(100) NOT NULL ENABLE,
"TARGETTYPEDESCR" VARCHAR2(255 CHAR),
"ACTIVE" CHAR(1) DEFAULT 'Y' NOT NULL ENABLE,
CONSTRAINT "TARGETTYPES_PK" PRIMARY KEY ("TARGETTYPECODE")
)
I created grails domain class:
package tmsconf
class Targettypes {
static transients = ['Targettypecode']
void setTargettypecode(String Targettypecode) {
id = Targettypecode
}
String getTargettypecode() {
return Targettypecode
}
String targettypedescr
String active
static mapping = {
table 'TARGETTYPES'
version false
columns {
id generator:'assigned', column:"TARGETTYPECODE", type:'text'
}
}
static constraints = {
id()
targettypecode(size: 1..100, blank: false)
targettypedescr(size: 0..255)
active(size: 1..1, blank: false)
id(nullable: true)
}
String toString() {
return "${targettypecode}"
}
}
Also I created controller class:
package tmsconf
class TargettypesController {
def scaffold = true
}
Application has started successfully.
When I click on link tmsconf.TargettypesController I have error in console:
Error 2012-10-10 10:55:37,243 [http-bio-8080-exec-9] ERROR util.JDBCExceptionReporter - ORA-00918: column ambiguously defined
| Error 2012-10-10 10:55:37,305 [http-bio-8080-exec-9] ERROR errors.GrailsExceptionResolver - SQLSyntaxErrorException occurred when processing request: [GET] /TMSConf/targettypes/list
ORA-00918: column ambiguously defined
. Stacktrace follows:
Message: ORA-00918: column ambiguously defined
Line | Method
->> 445 | processError in oracle.jdbc.driver.T4CTTIoer
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
| 396 | processError in ''
| 879 | processError . . . . in oracle.jdbc.driver.T4C8Oall
| 450 | receive in oracle.jdbc.driver.T4CTTIfun
| 192 | doRPC . . . . . . . in ''
| 531 | doOALL in oracle.jdbc.driver.T4C8Oall
| 207 | doOall8 . . . . . . in oracle.jdbc.driver.T4CPreparedStatement
| 884 | executeForDescribe in ''
| 1167 | executeMaybeDescribe in oracle.jdbc.driver.OracleStatement
| 1289 | doExecuteWithTimeout in ''
| 3584 | executeInternal . . in oracle.jdbc.driver.OraclePreparedStatement
| 3628 | executeQuery in ''
| 1493 | executeQuery . . . . in oracle.jdbc.driver.OraclePreparedStatementWrapper
| 96 | executeQuery in org.apache.commons.dbcp.DelegatingPreparedStatement
| 55 | <init> . . . . . . . in grails.orm.PagedResultList
| 15 | list in tmsconf.TargettypesController
| 186 | doFilter . . . . . . in grails.plugin.cache.web.filter.PageFragmentCachingFilter
| 63 | doFilter in grails.plugin.cache.web.filter.AbstractFilter
| 1110 | runWorker . . . . . in java.util.concurrent.ThreadPoolExecutor
| 603 | run in java.util.concurrent.ThreadPoolExecutor$Worker
^ 722 | run . . . . . . . . in java.lang.Thread
Please help, where am I wrong

Answer 1

This should work:
package tmsconf
class Targettypes {
String targettypecode
String targettypedescr
String active
static mapping = {
version false
id generator: 'assigned', name: 'targettypecode'
}
static constraints = {
targettypecode(size: 1..100, blank: false)
targettypedescr(size: 0..255, nullable: true)
active(size: 1..1, blank: false)
}
String toString() {
targettypecode
}
}
You can now use the name property in the mapping block, so creating a transient get/set pair to wrap the id isn't needed.
I also removed the table name and column name settings since they're set to what would be used anyway, and removed type:'text' since Hibernate knows the type of the field, so it can use that for the type of the column.
Also, I added nullable: true for targettypedescr based on the SQL you showed.
In general when you're trying to map to legacy databases, use the http://grails.org/doc/latest/ref/Command%20Line/schema-export.html script to look at what Hibernate thinks the tables should look like. Tweak the constraints and mapping blocks until it's "close enough".