I have 2 input dates: myStartDate,myEndDate and a table TEST_TABLE with columns
TEST_ID, TEST_USER,TEST_START, TEST_END
I need to check if the range of dates between myStartDate and myEndDate have corresponding records in the TEST_TABLE.
I also need to ensure that I don't retrieve duplicate records.
Here's a sample of the logic I have so far:
Assuming,
myStartDate=06/06/2012;myEndDate=06/09/2012
int diff = myEndDate - myStartDate; //In this case = 3
String myQuery = "SELECT * FROM TEST_TABLE WHERE"+ myStartDate +"BETWEEN TEST_START AND TEST_END OR "+ (myStartDate +1) +" BETWEEN TEST_START AND TEST_END OR"+ (myStartDate+2)+"BETWEEN TEST_START AND TEST_END OR"+(myStartDate+3)+"BETWEEN TEST_START AND TEST_END";
List <TestTableData> myList = new List();
//Exceute query & save results into myList using add method
Want to know if there's any way to test the range of dates between myStartDate &myEndDate using a for loop in java code, instead of the approach used above in myQuery.Also, how can I avoid duplicates.
New to Java so any help would be appreciated!
Use a ResultSet to iterate over the output, like the code below.
while (res.next()) {
String col1= res.getString("col1");
String col2 = res.getString("col2");
}
If you use an Array implementation , it does not allow for duplicate elements and hence there is no need to check for one.
But if you must use a list then , you could use the following code to remove any duplicate elements.
public static void removeDuplicates(List list)
{
Set set = new HashSet();
List newList = new ArrayList();
for (Iterator iter = list.iterator(); iter.hasNext(); ) {
Object element = iter.next();
if (set.add(element))
newList.add(element);
}
list.clear();
list.addAll(newList);
}
I think what you are asking are some generic questions about how to read a database and how to handle dates in java. I will give you some sample code below. But I suggest you look at the java database tutorial http://docs.oracle.com/javase/tutorial/jdbc/index.html and the java.util.Date api doc http://docs.oracle.com/javase/1.5.0/docs/api/java/sql/Date.html for more info.
Here is some sample code that specifically demonstrates how to implement your question:
// get the input dates
// they are hard coded in this example
// but would probably normally be passed in
String startDateStr = "2/3/03";
String endDateStr = "3/1/03";
// unfortunately, there are 2 "Date" classes in this code and you need to differentiate
// java.util.Date is the standard java class for manipulating dates
// java.sql.Date is used to handle dates in the database
// name conflicts like this are rare in Java
SimpleDateFormat dateFmt = new SimpleDateFormat("M/d/yy");
java.util.Date myStartDate = dateFmt.parse(startDateStr);
java.util.Date myEndDate = dateFmt.parse(endDateStr);
// conneect to the database
// I am using mysql and its driver class is "com.mysql.jdbc.Driver"
// if using a different database, you would use its driver instead
// make sure the jar containing the driver is in your classpath (library list)
// you also have to know the url string that connects to your database
Class.forName("com.mysql.jdbc.Driver").newInstance(); // loads the driver
Connection dbConn = DriverManager.getConnection(
"jdbc:mysql://localhost/testdb", "(db user)", "(db password)"
);
// get the database rows from the db table
// my table is named "testtable"
// my columns are named "DateStart" and "DateEnd"
Statement st = dbConn.createStatement();
String sqlStr = "Select * from testtable";
ResultSet rs = st.executeQuery(sqlStr);
// loop through the rows until you find a row with the right date range
boolean foundRange = false;
while (rs.next()) {
java.util.Date dbStartDate = rs.getDate("DateStart");
java.util.Date dbEndDate = rs.getDate("DateEnd");
if (myStartDate.before(dbStartDate)) continue;
if (myEndDate.after(dbEndDate)) continue;
foundRange = true;
break;
}
if (foundRange) {
// code that executes when range is found in db
} else {
// code that executes if range not found in db
}
dbConn.close();
Hope this helps you get started.
Related
We created a program to make the use of the database easier in other programs. So the code im showing gets used in multiple other programs.
One of those other programs gets about 10,000 records from one of our clients and has to check if these are in our database already. If not we insert them into the database (they can also change and have to be updated then).
To make this easy we load all the entries from our whole table (at the moment 120,000), create a class for every entry we get and put all of them into a Hashmap.
The loading of the whole table this way takes around 5 minutes. Also we sometimes have to restart the program because we run into a GC overhead error because we work on limited hardware. Do you have an idea of how we can improve the performance?
Here is the code to load all entries (we have a global limit of 10.000 entries per query so we use a loop):
public Map<String, IMasterDataSet> getAllInformationObjects(ISession session) throws MasterDataException {
IQueryExpression qe;
IQueryParameter qp;
// our main SDP class
Constructor<?> constructorForSDPbaseClass = getStandardConstructor();
SimpleDateFormat itaTimestampFormat = new SimpleDateFormat("yyyyMMddHHmmssSSS");
// search in standard time range (modification date!)
Calendar cal = Calendar.getInstance();
cal.set(2010, Calendar.JANUARY, 1);
Date startDate = cal.getTime();
Date endDate = new Date();
Long startDateL = Long.parseLong(itaTimestampFormat.format(startDate));
Long endDateL = Long.parseLong(itaTimestampFormat.format(endDate));
IDescriptor modDesc = IBVRIDescriptor.ModificationDate.getDescriptor(session);
// count once before to determine initial capacities for hash map/set
IBVRIArchiveClass SDP_ARCHIVECLASS = getMasterDataPropertyBag().getSDP_ARCHIVECLASS();
qe = SDP_ARCHIVECLASS.getQueryExpression(session);
qp = session.getDocumentServer().getClassFactory()
.getQueryParameterInstance(session, new String[] {SDP_ARCHIVECLASS.getDatabaseName(session)}, null, null);
qp.setExpression(qe);
qp.setHitLimitThreshold(0);
qp.setHitLimit(0);
int nrOfHitsTotal = session.getDocumentServer().queryCount(session, qp, "*");
int initialCapacity = (int) (nrOfHitsTotal / 0.75 + 1);
// MD sets; and objects already done (here: document ID)
HashSet<String> objDone = new HashSet<>(initialCapacity);
HashMap<String, IMasterDataSet> objRes = new HashMap<>(initialCapacity);
qp.close();
// do queries until hit count is smaller than 10.000
// use modification date
boolean keepGoing = true;
while(keepGoing) {
// construct query expression
// - basic part: Modification date & class type
// a. doc. class type
qe = SDP_ARCHIVECLASS.getQueryExpression(session);
// b. ID
qe = SearchUtil.appendQueryExpressionWithANDoperator(session, qe,
new PlainExpression(modDesc.getQueryLiteral() + " BETWEEN " + startDateL + " AND " + endDateL));
// 2. Query Parameter: set database; set expression
qp = session.getDocumentServer().getClassFactory()
.getQueryParameterInstance(session, new String[] {SDP_ARCHIVECLASS.getDatabaseName(session)}, null, null);
qp.setExpression(qe);
// order by modification date; hitlimit = 0 -> no hitlimit, but the usual 10.000 max
qp.setOrderByExpression(session.getDocumentServer().getClassFactory().getOrderByExpressionInstance(modDesc, true));
qp.setHitLimitThreshold(0);
qp.setHitLimit(0);
// Do not sort by modification date;
qp.setHints("+NoDefaultOrderBy");
keepGoing = false;
IInformationObject[] hits = null;
IDocumentHitList hitList = null;
hitList = session.getDocumentServer().query(qp, session);
IDocument doc;
if (hitList.getTotalHitCount() > 0) {
hits = hitList.getInformationObjects();
for (IInformationObject hit : hits) {
String objID = hit.getID();
if(!objDone.contains(objID)) {
// do something with this object and the class
// here: construct a new SDP sub class object and give it back via interface
doc = (IDocument) hit;
IMasterDataSet mdSet;
try {
mdSet = (IMasterDataSet) constructorForSDPbaseClass.newInstance(session, doc);
} catch (Exception e) {
// cause for this
String cause = (e.getCause() != null) ? e.getCause().toString() : MasterDataException.ERRMSG_PART_UNKNOWN;
throw new MasterDataException(MasterDataException.ERRMSG_NOINSTANCE_POSSIBLE, this.getClass().getSimpleName(), e.toString(), cause);
}
objRes.put(mdSet.getID(), mdSet);
objDone.add(objID);
}
}
doc = (IDocument) hits[hits.length - 1];
Date lastModDate = ((IDateValue) doc.getDescriptor(modDesc).getValues()[0]).getValue();
startDateL = Long.parseLong(itaTimestampFormat.format(lastModDate));
keepGoing = (hits.length >= 10000 || hitList.isResultSetTruncated());
}
qp.close();
}
return objRes;
}
Loading 120,000 rows (and more) each time will not scale very well, and your solution may not work in the future as the record size grows. Instead let the database server handle the problem.
Your table needs to have a primary key or unique key based on the columns of the records. Iterate through the 10,000 records performing JDBC SQL update to modify all field values with where clause to exactly match primary/unique key.
update BLAH set COL1 = ?, COL2 = ? where PKCOL = ?; // ... AND PKCOL2 =? ...
This modifies an existing row or does nothing at all - and JDBC executeUpate() will return 0 or 1 indicating number of rows changed. If number of rows changed was zero you have detected a new record which does not exist, so perform insert for that new record only.
insert into BLAH (COL1, COL2, ... PKCOL) values (?,?, ..., ?);
You can decide whether to run 10,000 updates followed by however many inserts are needed, or do update+optional insert, and remember JDBC batch statements / auto-commit off may help speed things up.
I have a stored procedure in mysql that returns more than one lines.
My java code to execute it is:
preparedStmt = conn.prepareCall(queryString);
preparedStmt.setString(1, String.valueOf(patient_id));
//System.out.print("select patient data java file 1 ");
boolean results = preparedStmt.execute();
int rowsAffected = 0;
// Protects against lack of SET NOCOUNT in stored procedure
while (results || rowsAffected != -1) {
if (results) {
rs = preparedStmt.getResultSet();
break;
} else {
rowsAffected = preparedStmt.getUpdateCount();
}
results = preparedStmt.getMoreResults();
}
int i = 0;
obj = new JSONObject();
while (rs.next()) {
JSONArray alist = new JSONArray();
alist.put(rs.getString("patient_id"));
alist.put(rs.getString("allergy"));
alist.put(rs.getString("allergy_description"));
alist.put(rs.getString("allergy_onset_date"));
alist.put(rs.getString("agent_description"));
alist.put(rs.getString("agent"));
alist.put(rs.getString("severity"));
obj.put("ps_allergies", alist);
i++;
}
conn.close();
At the end, ps_allergies json object contains only the last line of the query. This is the print output:
["1","week",null,"2017-07-07","vacation home","test2","mobile contact"]
I want ps_allergies to contain something similar to
[["1","hydrogen peroxide","Nuts","2017-07-04","Nursing profressionals","43","Paramedical practinioners"],["1","week",null,"2017-07-07","vacation home","test2","mobile contact"]...]
Do you know how to fix this?
Not exactly knowing what library you use, but it might have something to do with this line:
obj.put("ps_allergies", alist);
A put method in general associates the specified value with the specified key in a map. Since you are constantly overwriting you key 'ps_allergies' in the loop it will only retain the last value.
You might want to associate a list/array to ps_allergies and you then add every alist object in this list/array.
I found the solution. Instead of put I'm using append method.
obj.append("ps_allergies", alist);
The resulted output now is:
[["1","hydrogen peroxide","Nuts","2017-07-04","Nursing professionals","43","Paramedical practitioners"],["1","chlorhexidine","test123","2017-07-15","mobile contact","test232","pager"],["1","Resistance to unspecified antibiotic","Feb3","2017-03-02","mobile contact","test232","pager"],["1","week",null,"2017-07-07","vacation home","test2","mobile contact"]]
How can i can reset the transactions number from ONE if new month is come.. for example, last entry is 17020005 become 17030001. The code is working but not reset transaction number from one when new month is come.
The code which i am using is
public void new(){
Date date =new Date();
SimpleDateFormat sdf = new SimpleDateFormat("yyMM");
String time = sdf.format(date);
try{
Connection con = new Connection ();
con.openConnection();
con.statement = con.dbConnection.createStatement();
ResultSet rs = con.statement.executeQuery("select right(id_sell,4) as id from sell");
if (rs.first()==false){
txtId.setText(time+"0001");
}
else
{
rs.last();
int no = rs.getInt(1)+1;
String cno = String.valueOf(no);
int pjg_cno = cno.length();
for (int i=0;i<4-pjg_cno;i++){
cno = "0"+cno;
}
txtId.setText(time+cno);
}
}catch (Exception e){
JOptionPane.showMessageDialog(null, "Fail!");
}
}
As Henry suggests, it looks like your "id_sell" values are made up of the year, month and a unique integer - if so, you could change your SQL query to include a WHERE clause to match the first four digits of your time string - WHERE id_sell LIKE '1703%'.
However, long term (and assuming you control the DB structure), I'd suggest thinking about storing those values separately - if you had a month field and a transaction_id field it would be much easier and more efficient to query this data.
I'd also suggest thinking about whether you could generate IDs on the database using a sequence - it's hard for this java code to guarantee uniqueness and raises potential concurrency issues.
I can't seem to update an existing record in my table using a strongly-typed dataset. I can add a new record, but if I make changes to an existing record it doesn't work.
Here is my code:
private void AddEmplMaster()
{
dsEmplMast dsEmpMst = new dsEmplMast();
SqlConnection cn = new SqlConnection();
cn.ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["cn.ConnectionString"];
SqlDataAdapter da1 = new SqlDataAdapter("SELECT * FROM UPR00100", cn);
SqlCommandBuilder cb1 = new SqlCommandBuilder(da1);
da1.Fill(dsEmpMst.UPR00100);
DataTable dtMst = UpdateEmpMst(dsEmpMst);
da1.Update(dsEmpMst.UPR00100);
}
This procedure is called from above to assign the changed fields to a record:
private DataTable UpdateEmpMst(dsEmplMast dsEmpMst)
{
DataTable dtMst = new DataTable();
try
{
dsEmplMast.UPR00100Row empRow = dsEmpMst.UPR00100.NewUPR00100Row();
empRow.EMPLOYID = txtEmplId.Text.Trim();
empRow.LASTNAME = txtLastName.Text.Trim();
empRow.FRSTNAME = txtFirstName.Text.Trim();
empRow.MIDLNAME = txtMidName.Text.Trim();
empRow.ADRSCODE = "PRIMARY";
empRow.SOCSCNUM = txtSSN.Text.Trim();
empRow.DEPRTMNT = ddlDept.SelectedValue.Trim();
empRow.JOBTITLE = txtJobTitle.Text.Trim();
empRow.STRTDATE = DateTime.Today;
empRow.EMPLOYMENTTYPE = "1";
dsEmpMst.UPR00100.Rows.Add(empRow);
}
catch { }
return dtMst;
}
Thank you
UPDATE:
Ok I figured it out. In my UpdateEmpMst() procedure I had to check if the record exists then to retrieve it first. If not then create a new record to add. Here is what I added:
try
{
dsEmplMast.UPR00100Row empRow;
empRow = dsEmpMst.UPR00100.FindByEMPLOYID(txtEmplId.Text.Trim());
if (empRow == null)
{
empRow = dsEmpMst.UPR00100.NewUPR00100Row();
dsEmpMst.UPR00100.Rows.Add(empRow);
}
then I assign my data to the new empRow I created and updates fine.
In order to edit an existing record in a dataset, you need to access a particular column of data in a particular row. The data in both typed and untyped datasets can be accessed via the following:
With the indices of the tables, rows, and columns collections.
By passing the table and column names as strings to their respective collections.
Although typed datasets can use the same syntax as untyped datasets, there are additional advantages to using typed datasets. For more information, see the "To update existing records using typed datasets" section below.
To update existing records in either typed or untyped datasets
Assign a value to a specific column within a DataRow object.
The table and column names of untyped datasets are not available at design time and must be accessed through their respective indices.
i have 3 string list called Cname,cnamedb,Pname. These 3 lists has a result obtained by query the SQL database.cname and Pname results are getting from querying excel database. cnamedb result is getting from querying SQL database.
i declared and stored into array like this.
List Cname = new ArrayList();
List Pname =new ArrayList();
List cnamedb=new ArrayList();
Cname.add(rs.getString("Cname"));
Pname.add(rs.getString("Pname"));
cnamedb.add(res.getString("Cname"));
i tried like this
boolean hasCommonName = Cname.retainAll(Cnamedb);
if(hasCommonName){
out.println(Cname+"<br>");
out.println(hasCommonName);
}
boolean haspname=Pname.retainAll(Cnamedb);
if(haspname){
out.println(haspname);
}
This is just giving me a answer true for the first if statement but not printing the list elements. for the second if statements no results am getting.
i need to find out common elements exists in database and the excel, first i need to get common elements from Cname and Cnamedb and then from Pname and Cnamedb. how do i get the common elements.please provide me the code snippet.
the below given snippet worked for me.
List<String> commonToCnameAndCnamedb = new ArrayList<String>(Cname);
List<String> commonToPnameAndCnamedb = new ArrayList<String>(Pname);
boolean hasCommonName = commonToCnameAndCnamedb.retainAll(cnamedb);
if (hasCommonName) {
System.out.println(commonToCnameAndCnamedb + "<br>");
System.out.println(hasCommonName);
}
boolean haspname = commonToPnameAndCnamedb.retainAll(cnamedb);
if (haspname) {
System.out.println(commonToPnameAndCnamedb + "<br>");
System.out.println(haspname);
}