Not getting the right quantity in select

Question

Hi,
My company stores each week's transaction in one dbf table, thus, creating around 53 tables per year. I try to move the tables into one big table (bigTable) in mysql. I created a Java program to select the data from dbf (visual foxpro dbf driver) and insert into mysql using JConnect. After I finished inserting into mysql, I used Visual Foxpro and I do a:
SELECT sum(quant) from week532000.dbf
and obtained 52843.6, which I considered it the correct result.
* Note that 'quant' is of type Numeric in dbf.
However, when I do this with mysql client:
SELECT sum(qunt) from bigTable where date_ between '2000-12-25' AND '2000-12-31'. I obtained 52977.6, which is different from the original result.
To troubleshoot this, I created a small program just to select the 'quant' field and obtained the sum. It turned out that when I ran this program, I obtained a different sum (although I was selecting from the same table):
Example:
sum of quant is 52977.6
sum of quant is 52890.1
sum of quant is 52837.6
double q, qt;
try{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
con1 = DriverManager.getConnection("jdbc:odbc:daydata", "", "");
st = con1.createStatement();
rs = st.executeQuery("SELECT quant from wk532000 where quant <> 0");
while(rs.next()){
qt = rs.getDouble("quant");
q = q + qt;
rs.close();
st.close();
con1.close();
} catch(ClassNotFoundException e){
e.printStackTrace();
catch(SQLException e){
e.printStackTrace();
System.out.println("sum of quant is "+q);
Why a different sum was produced each time the code was run? Any feedback is appreciated.

Answer 1

what do you mean timestamp?One of the following is true.
1. You have a field in the database that holds a timestamp (a date and a time.) That is because that is the only thing that databases allow.
2. You have a varchar/char field that has a date in in as a string.
If the second is the case then the problem has nothing to do with java. It is one of the following
- Your migration is not migrating everything.
- Your comparisons are not equivalent in terms of functionality.
If the first then it could still be one of the above problems but it could also be because the timestamp values are not equivalent.