I'm using the biglm package to run a regression on a data set.  The regression runs fine using the following code: 

chunkStart &lt;- seq(1,150000000,1000000)
chunkEnd &lt;- seq(1000000,151000000,1000000)
ff &lt;- price ~ factor(Var1) + factor(Var2)

#for(i in 1:length(chunkStart)){
for(i in 1:5){

startRow &lt;- chunkStart[i]
endRow &lt;- chunkEnd[i]    
curchunk &lt;- data.frame( price=x[startRow:endRow,1]
     ,Var1=factor( x[startRow:endRow,6], levels=1:3), Var2= factor( x[startRow:endRow,7], levels=1:3 ) )

    if(i == 1){
    a &lt;- biglm(ff,curchunk )
    }
    if(i != 1){
    a &lt;- update(a,curchunk )
    }
rm(curchunk )
gc()
print(paste(i, " | ",startRow ," | ",endRow ," | ", sep=""))
flush.console()
}

&gt; summary(a)
Large data regression model: biglm(ff, curchunk)
Sample size =  5000000 
                 Coef    (95%     CI)    SE p
(Intercept)    0.0457  0.0454  0.0461 2e-04 0
factor(Var1)2  0.0189  0.0184  0.0194 2e-04 0
factor(Var1)3  0.0148  0.0142  0.0155 3e-04 0
factor(Var2)2 -0.0331 -0.0335 -0.0326 2e-04 0
factor(Var2)3 -0.0417 -0.0426 -0.0408 4e-04 0


The problems come when I try to predict using the biglm object, 'a'. 

&gt; df1 &lt;- data.frame(y[1:1000,])
&gt; pred1 &lt;- predict(a, df1)
Error in eval(expr, envir, enclos) : object 'price' not found


Why is the predict function looking for the price/ dependent variable?  Any suggestions?

EDIT: 

&gt; head(df1)
  Var1 Var2
1    3    3
2    3    1
3    3    2
4    2    1
5    2    2
6    1    1
&gt; str(df1)
'data.frame':   1000 obs. of  2 variables:
 $ Var1: Factor w/ 3 levels "1","2","3": 3 3 3 2 2 1 2 1 2 1 ...
 $ Var2: Factor w/ 3 levels "1","2","3": 3 1 2 1 2 1 1 1 2 1 ...
&gt; pred1 &lt;- predict(a, df1)
Error in eval(expr, envir, enclos) : object 'price' not found



Question: Hibernate does not allow an embedded object with an int field to be null?
Answer: I found another workaround and thought I'd share it.  Turns out that if you make the int column nullable then Hibernate doesn't throw the PropertyValueException.

@Column(nullable = true)
public int b;


This works for us because our hibernate enabled application is the only thing that touched the database and so we can guarantee that b is null only when the part is null.  Although the null part suggestion and the use of the Integer wrapper type are great suggestions, due to lots of reasons I don't really have control over, setting the column to nullable works best for us.  Thanks though and I hope this helps someone else.