I'm using JFreeChart to create a chart in Java and MySQL.
When I try to insert my values in another table the query seems to be executed twice since I end up with the same timestamps multiple times...
Here's a part of my code :
private JDBCXYDataset createDataset() {
try {
Connection conn = DriverManager.getConnection(
"jdbc:mysql://localhost:bd?serverTimezone=UTC","MySQL", "MySQL");
conn.setAutoCommit(false);
SQLException savedException = null;
Statement st = conn.createStatement();
st.execute("DROP TABLE IF EXISTS test ");
st.execute("create table test(Table timestamp, Table float,Table float)");
String Date_Debut = "2020-06-25 00:00:00";
String Date_Fin = "2020-06-26 00:00:00";
String sql1 = "INSERT INTO test (Table ,Table ,Table ) "
+ "SELECT Table ,Table ,Table "
+ "FROM Table "
+ "WHERE Table BETWEEN ? AND ? ";
try ( PreparedStatement ps = conn.prepareStatement(sql1)){
ps.setString(1,Date_Debut);
ps.setString(2, Date_Fin);
ps.executeUpdate();
ps.close();
JDBCXYDataset jds = new JDBCXYDataset(conn);
st.close();
jds.executeQuery("SELECT Table ,Table ,Table FROM test");
conn.commit();
return jds;
} catch (SQLException ex) {
savedException = ex;
conn.rollback();
} finally {
conn.setAutoCommit(true);
if(savedException != null) {
throw savedException;
}
}
} catch (SQLException ex1) {
}
return null;
}
EDIT : Actually it seems like the errors where comming directly from the database, the moderators can delete this post if they want. However I keep Trashgod's response validated as it was more than helpful.
For everyone that might come here with a similar issue, inspect in detail your database first to see if it isn't comming from there instead of your code.
Chasing down anomalies in data is arduous, but JFreeChart can at least make the result easier to visualize. Some heuristics for testing:
To verify that the the presumed duplicates in your tabular listing are indeed duplicates, format the timestamps to include milliseconds, e.g. add an S to a SimpleDateFormat or A to a DateTimeFormatter.
For study, temporarily pass the query directly to JDBCXYDataset, and add an ORDER BY clause (untested):
jds.executeQuery(
"SELECT Date_Heure, PV, SV FROM cmd3 "
+ "WHERE Date_Heure BETWEEN "
+ "2020-06-25 00:00:00 AND 2020-06-26 00:00:00 "
+ "ORDER BY Date_Heure");
Enable tooltips in your ChartFactory, as you did here, to see data values in situ. This may suggest additional conditions for your WHERE clause, e.g. PV BETWEEN 5.1 AND 5.9.
Use the interactive JFreeChart pan/zoom controls, discussed here to examine the data; add suitable buttons, shown here, if it will make it easier for colleagues to see your findings.
By design, JDBCXYDataset executes a query defined by a String. If your design needs to display data from a query defined by a PreparedStatement, you can use the existing implementation as a guide.
public class PreparedDataset extends AbstractXYDataset
implements XYDataset, TableXYDataset, RangeInfo {
private final PreparedStatement ps;
public PreparedDataset(PreparedStatement ps) {
this.ps = ps;
}
…
}
Related
This is the code where I'm trying to execute a second query on the resultSet of my first lengthy query. I need to upload this
data somewhere.
Is it the right thing to do?
Or is there a better approach apart from querying the database again?
public String createQuery() throws SQLException {
StringBuilder Query = new StringBuilder();
try {
Query.append(" SELECT ...... ")
} catch (Exception e) {
e.printStackTrace();
}
return Query.toString();
}
private void openPreparedStatements() throws SQLException {
myQuery = createQuery();
try {
QueryStatement = dbConnection.prepareStatement(myQuery);
} catch (SQLException e) {
e.printStackTrace();
return;
}
}
public ResultSet selectData(String timestamp) throws SQLException {
openConnection();
ResultSet result = null;
ResultSet rs_new=null;
try {
result = QueryStatement.executeQuery();
while (result.next()) {
String query = "SELECT * FROM " + result + " WHERE " + "ID" + " =" + "ABC";
rs_new =QueryStatementNew.executeQuery(query);
System.out.print(rs_new);
}
} catch (SQLException e) {
LOGGER.info("Exception", e);
}
return result;
}
Instead of running two separate queries (when you don't need the intermediate one) you can combine them.
For example you can do:
SELECT *
FROM (
-- first query here
) x
WHERE ID = 'ABC'
You cannot use two statement objects within one database connection. So you can either open another database connection and execute the second statement in the 2nd connection, or iterate through the resultset from first statement and store the value you need (e.g. in an array/collection) then close that statement and run the second one, this time retrieving the value from the array/collection you saved them in. Refer to Java generating query from resultSet and executing the new query
Make Db2 keep your intermediate result set in a Global Temporary Table, if you have an ability to use it, and you application uses the same database connection session.
DECLARE GLOBAL TEMPORARY TABLE SESSION.TMP_RES AS
(
SELECT ID, ... -- Your first lengthy query text goes here
) WITH DATA WITH REPLACE ON COMMIT PRESERVE ROWS NOT LOGGED;
You may send the result of subsequent SELECT ... FROM SESSION.TMP_RES to FTP, and the result of SELECT * FROM SESSION.TMP_RES WHERE ID = 'ABC' to elastic.
Hi I have a problem with my syntax in my java code. I have a tableview which gets its data from a SQL database. I have created 3 tables in the database book, customer, order. When I click a button I want to take the selected books and add them to the order table.
Here is the code from the main program (calling the method from db):
if(table.getSelectionModel().getSelectedItems().iterator().hasNext()) {
db.insertOrder(new Bestellung(customerid,table.getSelectionModel().getSelectedItems().iterator().next()));
The table book is fixed. Just the two other tables customer,order are dynamic.
The problem:
I create the values in the order table like this
String ct = "CREATE TABLE Order (" + "Order_Id integer generated always as identity, " + "CUSTOMER_ID BIGINT" + "ISBN, CHAR(13) " + "PRIMARY KEY(Order_Id))";
and so on...
I insert into order table like this. (Here is the syntax problem in the String i That's the position where the compiler says it doesn't work..)
String i = "INSERT INTO ORDER(CUSTOMER_ID,ISBN), VALUES(?,?)";
Connection conn = null;
PreparedStatement stmt = null;
try {
conn = DriverManager.getConnection(connString);
stmt = conn.prepareStatement(i);
conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
stmt.setLong(1, order.getCustomerId());
stmt.setString(2, order.getBuch().getISBN());
stmt.executeUpdate();
} catch (SQLException e) {
System.out.println(e.getMessage());
e.printStackTrace();
}
finally {
try {
if (stmt != null)
stmt.close();
if (conn != null)
conn.close();
} catch (SQLException e) {
System.out.println(e.getMessage());
e.printStackTrace();
}
}
and here is the syntax error which I got
Syntax error: Encountered "ORDER" at line 1, column 13.
So how do I have to correct my syntax in the string i? Does anyone have any ideas?
INSERT INTO ORDER(CUSTOMER_ID,ISBN), VALUES(?,?)
^
The comma is superfluous. Also, in your CREATE TABLE
... + "ISBN, CHAR(13) " + ...
^
This comma is also extraneous.
If you want to use reserved words/keywords as Table name, you should:
MySQL: use ' , like : select * from 'Order'
Oracle, PostgreSQL: use " , like : select * from "Order"
But it is bad practice, try to change your table name.
You have another Error that answered by #Jim Garrison.
I want to select all data from database table between given 2 specific dates and add that data to a jtable.
Below is my code to retrieve data from the database; But all the data is not shown by this code .. What is the error I done here?
private void updateTable(){
String fday = ((JTextField)day_chooser.getDateEditor().getUiComponent()).getText();
String tday = ((JTextField)day_chooser.getDateEditor().getUiComponent()).getText();
try {
String sql = "SELECT * FROM saleinfo WHERE SaleDate BETWEEN '"+fday+"' AND '"+tday+"'";
pst=conn.prepareStatement(sql);
rs=pst.executeQuery();
tbl.setModel(DbUtils.resultSetToTableModel(rs));
} catch (Exception ex) {
JOptionPane.showMessageDialog(null, "Error : "+ex);
}
}
Leverage the JDBC drive and it's ability to map between data types from Java to the database, leverage the power of the PreparedStatement
I'm using prepared statements pst is the prepare statement
BUT, you're not using it properly, see Using Prepared Statements for more details.
Start by getting the Date value from the date picker (I'm guessing here, but I assume they have some kind of getDate method) and then bind the values to the wildcard columns of the query, for example...
Date fday = day_chooser.getDate();
Date tday = day_chooser.getDate();
try {
String sql = "SELECT * FROM saleinfo WHERE SaleDate BETWEEN ? AND ?";
try (PreparedStatement pst = conn.prepareStatement(sql)) {
pst.setDate(1, new java.sql.Date(fday.getTime()));
pst.setDate(2, new java.sql.Date(tday.getTime()));
try (ResultSet rs = pst.executeQuery()) {
tbl.setModel(DbUtils.resultSetToTableModel(rs));
}
}
} catch (Exception ex) {
JOptionPane.showMessageDialog(null, "Error : " + ex);
ex.printStackTrace();
}
Don't assume anything about the format, this will just cause you no end of grieve if you ever have to change databases
Basically, I have to show a list with the data from a database table [that part is working] and afterwards I have to show the highest Date [a date variable in the table]. The second part is not working no matter what I do.
Here's the code
try {
String SQL = "SELECT * FROM tb_rafael";
ResultSet rs = BD.consultar(SQL);
String tab = "";
int numReg = 0;
while (rs.next()) {
tab+="<TR>";
tab+="<TD>" + rs.getString("nme_rafael") + "</TD>";
tab+="<TD>" + rs.getString("dta_rafael") + "</TD>";
tab+="</TR>";
numReg++;
//mDat = rs2.getString("dta_rafael");
}
rs.close();
dados.put("DADOS", tab);
dados.put("NUM_REG", String.valueOf(numReg));
//Pegar Data Maior
String SQL2 = "SELECT MAX(dta_rafael) FROM tb_rafael";
ResultSet rs2 = BD.consultar(SQL2);
String mDat = "";
//while(rs2.next()){
mDat = rs2.getString("dta_rafael");
//}
rs2.close();
dados.put("MDA", mDat);
} catch (Exception ex) {
dados.put("MSG", "Erro: " + ex.getMessage());
}
What you want to look at is past the commentary line "Pegar Data Maior". That's the part that is not working. I've tried adding a while, using a different ResultSet, using the same ResultSet and none of those worked. I know it's not an issue with the SQL query since I tested it with the workbench and it returned me the data I want.
To be more specific, I don't get an error message or anything, the dados.put simply does not work and I get just this:
How the HTML code looks:
The data should show up where the {MDA} is. Anyone have any ideas?
The query SELECT MAX(dta_rafael) FROM tb_rafael may not return a column name, which you later try to retrieve, rs2.getString("dta_rafael");
I'd change the query to SELECT MAX(dta_rafael) AS Max_date..., and reference to MAX_date thereafter.
I am trying to figure out why ResultSet.next() is never true in Java code that I am writing after I execute a SQL query that returns results from an Oracle 11g table into that ResultSet... it seems as though the code does not pick up a returned ResultSet's contents correctly when using a PreparedStatement in a java.sql.Connection. Any help appreciated, here are the details:
Table:
CREATE TABLE "SHANDB"."ABSCLOBS"
( "ID" NUMBER,
"XMLVAL" "XMLTYPE",
"IDSTRING" VARCHAR2(20 BYTE)
)
Data:
INSERT INTO absclobs VALUES ( 1,
xmltype('<?xml version="1.0"?>
<EMP>
<EMPNO>221</EMPNO>
<ENAME>John</ENAME>
</EMP>', '1'));
INSERT INTO absclobs VALUES (2,
xmltype('<?xml version="1.0"?>
<PO>
<PONO>331</PONO>
<PONAME>PO_1</PONAME>
</PO>', '2'));
Java code I am running to get values from the above to test the code:
public static void main(String[] args) throws Exception {
try {
String url = "jdbc:oracle:thin:#//localhost:1521/xe";
String driver = "sun.jdbc.odbc.JdbcOdbcDriver";
String user = "shandb";
String password = "test";
Class.forName(driver);
connection = DriverManager.getConnection(url,user, password);
String selectID1 = "SELECT a.xmlval.getClobval() AS poXML FROM absclobs a where idstring=? and id=? ";
PreparedStatement preparedStatement = connection.prepareStatement(selectID1);
preparedStatement.setString(1, "1");
preparedStatement.setInt(2, 1);
rowsUpdated = preparedStatement.executeQuery();
while(rowsUpdated.next()){
String clobxml = rowsUpdated.getString(1);
System.out.println(clobxml);
}
} catch (ClassNotFoundException cnfe) {
System.err.println(cnfe);
} catch (SQLException sqle) {
System.err.println(sqle);
}
finally{
System.out.println("Rows affected: " + rowsUpdated);
connection.close();
}
}
This part of the above code is never run, which I don't understand:
while(rowsUpdated.next()){
String clobxml = rowsUpdated.getString(1);
System.out.println(clobxml);
}
... however the final print statement shows that the ResultSet is not empty:
Rows affected: oracle.jdbc.driver.OracleResultSetImpl#15f157b
Does anyone know why I can't display the actual retrieved XML clob contents, and/or why the while block above is never true?
Thanks :)
Your diagnostics are incorrect - this:
Rows affected: oracle.jdbc.driver.OracleResultSetImpl#15f157b
doesn't show that the result set is non-empty. It just shows that the value of rowsUpdated is a reference to an instance of oracle.jdbc.driver.OracleResultSetImpl, which doesn't override toString(). That can very easily be empty.
I suspect the problem is just that your WHERE clause doesn't match any records. For the sake of diagnostics, I suggest you change it to just:
String selectID1 = "SELECT a.xmlval.getClobval() AS poXML FROM absclobs a";
(and get rid of the parameter-setting calls, of course). That way you should be able to see all your table's values. You can then work on discovering why your WHERE clause wasn't working as expected.
(As an aside, it's not clear why you haven't declared connection or rowsUpdated in the code in the question. They should definitely be local variables...)