i have a problem >>
programming language: java
Data base: Mysql database
i write a java code for retrive the record from the database based on the data parameters comping from the method>>
the code is:
public static void Get_patient_data(String Hospital1_ID,String Hospital2_ID {
try {
Connection con = getConnection2();
PreparedStatement statement = (com.mysql.jdbc.PreparedStatement)
con.prepareStatement(
"SELECT PatientGender "+
"FROM patientcorepopulatedtable "+
"WHERE PatientID = Hospital1_ID LIMIT 1" );
ResultSet result = statement.executeQuery();
ArrayList<String> array = new ArrayList<String>();
while( result.next()) {
System.out.print("the patient Gender is" +
result.getString("PatientGender"));
}
}
catch(Exception e) {
System.out.println("Error"+e);
}
}
As you see the problem is Hospital1_ID parameter .. is coming from the method and the patientID is a column in a table patientcorepopulatedtable ...
the = equal operator doesn't work.
Try this
String query =
"SELECT PatientGender FROM patientcorepopulatedtable "+
" WHERE PatientID = ? LIMIT ?";
PreparedStatement preparedStmt = conn.prepareStatement(query);
preparedStmt.setString (1, Hospital1_ID);
preparedStmt.setInt (2, 1);
preparedStmt.executeQuery();
you can do it this way
PreparedStatement statement = (com.mysql.jdbc.PreparedStatement)
con.prepareStatement(
"SELECT PatientGender FROM patientcorepopulatedtable "+
"WHERE PatientID = ? LIMIT 1");
statement.setString(1, Hospital1_ID);
ResultSet result = statement.executeQuery();
you can find more info here
Related
I am trying to write a code that sum all the data in a column named AMOUNT between two rows in a column named DATA in a table named PERSON and I used the sum function and I use between function
and I got the following error:
java.sql.SQLSyntaxErrorException: Syntax error:
Encountered "BETWEEN" at line 1, column 45.
the code :
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
Connection con = null;
ResultSet rs = null;
PreparedStatement ps = null;
try {
String sql = "SELECT SUM(AMOUNT) AS SUMAMOUNT " +
"FROM PERSON BETWEEN DATE=? AND DATE=?";
con = DriverManager.getConnection("jdbc:derby://localhost:1527/Invoices",
"user1", "password");
ps = con.prepareStatement(sql);
ps.setString(1, jTextField1.getText());
ps.setString(2, jTextField2.getText());
rs = ps.executeQuery();
if (rs.next()) {
String sum = rs.getString("sumAmount");
jLabel3.setText(sum);
}
} catch(Exception ex) {
ex.printStackTrace();
}
}
Try something like this:
String sql = "SELECT SUM(AMOUNT) AS SUMAMOUNT FROM PERSON " +
"WHERE (col_name) between '2020-05-01 00:58:26' " +
"and '2021-06-18 19:53:17'";
I wrote code to run multiple statement in single connection. The first statement will retrieve IDs to be looped and used by the second statement then get the desired output. As example:
String sql1 = "SELECT ID FROM __TestParent WHERE Status = 'S'";
try (
Connection conn = DbConnector.getConnection();
Statement s = conn.createStatement();
Statement s2 = conn.createStatement();
ResultSet rs = s.executeQuery(sql1)
) {
while(rs.next()) {
String id = String.valueOf(rs.getInt("ID"));
String sql2 = "SELECT Description FROM __TestChild WHERE FK = " + id;
try (
ResultSet rs2 = s2.executeQuery(sql2)
) {
while(rs2.next())
Util.printLog("INFO",rs2.getString("Description"));
}catch(SQLTimeoutException sqltoex){
Util.printLog("SEVERE",sqltoex);
}catch(SQLException sqlex){
Util.printLog("SEVERE",sqlex);
}
}
}catch(SQLTimeoutException sqltoex){
Util.printLog("SEVERE",sqltoex);
}catch(SQLException sqlex){
Util.printLog("SEVERE",sqlex);
}
Util.printLog method is to print the message in the desired format
The code run perfectly fine and the output was as expected. What I want to know is:
Is this the right way to do it, or is/are there better way to write the code.
Is there anything that I need to be aware of? Because I seems cannot find anything about this use case other than this link Multiple-statements-single-connection from CodeRanch which is 16-year-old thread and I'm not quite clear other than driver support.
Thanks.
You can actually do what you want using a single query and result set:
SELECT c.Description
FROM __TestChild c
INNER JOIN __TestParent p
ON c.FK = p.ID
WHERE p.Status = 'S';
Code:
String sql = "SELECT c.Description FROM __TestChild c ";
sql += " INNER JOIN __TestParent p ON c.FK = p.ID ";
sql += "WHERE p.Status = 'S'";
try (
Connection conn = DbConnector.getConnection();
Statement s = conn.createStatement();
ResultSet rs = s.executeQuery(sql)
) {
while(rs.next()) {
Util.printLog("INFO", rs.getString("Description"));
}
} catch(SQLTimeoutException sqltoex) {
Util.printLog("SEVERE",sqltoex);
} catch(SQLException sqlex) {
Util.printLog("SEVERE",sqlex);
}
Using Statment, resultSet.getObject returns query plan as xml
Connection conn = getConnection();
String query = " SET SHOWPLAN_XML on ";
Statement st = conn.createStatement();
boolean execute=st.execute(query);
log.info("execute status {} " , execute);
query = " SELECT ATMPROFILES.TERMID as COLUMNID, ATMPROFILES.TERMID as COLUMNNAME FROM ATMPROFILES (NOLOCK) "
+ " WHERE Authprocessname = 'ATMST' "
+ "ORDER BY ATMPROFILES.TERMID ";
ResultSet rs = st.executeQuery(query);
while(rs.next())
{
Object object = rs.getObject(1);
log.info("Query Plan {} ", object);
}
But If I execute the same through PreparedStatement, it returns actual result insteadof QueryPlan
Connection conn = getConnection();
String query = " SET SHOWPLAN_XML on ";
PreparedStatement ps = conn.prepareStatement(query);
boolean execute = ps.execute();
log.info("execute status {} " , execute);
query = " SELECT ATMPROFILES.TERMID as COLUMNID, ATMPROFILES.TERMID as COLUMNNAME FROM ATMPROFILES (NOLOCK) "
+ " WHERE Authprocessname = 'ATMST' "
+ "ORDER BY ATMPROFILES.TERMID ";
ps=conn.prepareStatement(query);
execute=ps.execute();
log.info("execute status {} " , execute);
ResultSet rs = ps.getResultSet();
while(rs.next())
{
Object object = rs.getObject(1);
// here it returns selected object
log.info("Query Plan {} ", object);
}
Any idea to acheive this via PreparedStatement.
I haven't found any reference why executing SET SHOWPLAN_XML ON as a prepared statement will not work; however, you should get the desired results when you run this statement directly and your actual query as a prepared statement. In code:
Connection conn = getConnection();
String showplanQuery = "SET SHOWPLAN_XML ON";
Statement st = conn.createStatement();
st.execute(showplanQuery);
String actualQuery = "SELECT ATMPROFILES.TERMID FROM ATMPROFILES (NOLOCK) ";
PreparedStatement ps=conn.prepareStatement(actualQuery);
ps.execute();
ResultSet rs = ps.getResultSet();
while(rs.next())
{
Object object = rs.getObject(1);
// should log the query plan
log.info("Query Plan {} ", object);
}
Hope that helps.
I have problem with inserting data into mysql table. JDBC doesnt inserting data into mysql table.
JDBC should get value from input "liczbaUzytkownikow" and "data from table form which contains informations about "termin" (Exactly: termin.nazwaObiektu, termin.adresObiektu, termin.dzien, termin.odKtorej and termin.doKtorej).
Here is code of this JDBC:
conn = ConnectionClass.Polacz();
ArrayList<Rezerwacja> rezerwacje = new ArrayList<Rezerwacja>();
PreparedStatement st = null;
ResultSet rs = null;
String sql = "INSERT INTO rezerwacje (liczbaUczestnikow,idTermin) values ('" + liczbaUczestnikow + "','" + idTermin + "')"
+ "UPDATE termin SET termin.czyZajety=true WHERE termin.idTermin = '"+ idTermin +"'";
try
{
st = conn.prepareStatement(sql);
rs = st.executeQuery();
while(rs.next())
{
Rezerwacja rezerwacja = new Rezerwacja();
rezerwacja.setLiczbaUczestnikow(rs.getInt(1));
rezerwacja.setIdTermin(rs.getInt(2));
rezerwacje.add(rezerwacja);
}
}
catch(SQLException e)
{
System.out.println(e);
}
Any suggestions ?
You should use PreparedStatement to avoid sql injection attacks.
Furthermore your sql is wrong:
String sql = "INSERT INTO rezerwacje (liczbaUczestnikow,idTermin) values ('" + liczbaUczestnikow + "','" + idTermin + "')"
+ "UPDATE termin SET termin.czyZajety=true WHERE termin.idTermin = '"+ idTermin +"'";
you cannot execute two different statements in a single batch.
In your case an Insert and an Update.
Create two PreparedStatement's:
String sql1 = "INSERT INTO rezerwacje (liczbaUczestnikow,idTermin) values (?,?)";
String sql2 = "UPDATE termin SET termin.czyZajety=true WHERE termin.idTermin = ?";
PreparedStatement preparedStatement1 = con.prepareStatement(sql1);
preparedStatement1.setString(1, liczbaUczestnikow );
preparedStatement1.setInt(2, idTerminal);
PreparedStatement preparedStatement2 = con.prepareStatement(sql2);
preparedStatement2.setInt(1, idTerminal);
preparedStatement1.executeUpdate();
preparedStatement2.executeUpdate();
I have 5 or table table to query from \
my syntax i like this
String sql2 = "SELECT * FROM ? WHERE Patient_ID = ?";
pst = conn.prepareStatement(sql2);
System.out.println("SQL before values are set "+sql2);
System.out.println("The values of table/test name recieved in TestPrint stage 1 "+tblName);
System.out.println("The values of test name recieved in TestPrint stage 1 "+key);
// values are outputted correctly but are not getting set in the query
pst.setString(1, tblName);
pst.setLong(2, key);
ResultSet rs2 = pst.executeQuery(sql2);
while(rs2.next()){
String ID = rs2.getString("ID");
jLabel35.setText(ID);
jLabel37.setText(ID);
jLabel38.setText(ID);
// them print command is initiated to print the panel
}
The problem is when i run this i get an error saying ".....you have and error in SQL syntax near ? WHERE Patient_ID = ?"
When i output the sql using system.out.println(sql2);
values are not set in sql2
When you prepare a statement, the database constructs an execution plan, which it cannot do if the table is not there. In other words, placehodlers can only be used for values, not for object names or reserved words. You'd have to rely on Java to construct your string in such a case:
String sql = "SELECT * FROM `" + tblName + "` WHERE Patient_ID = ?";
pst = conn.prepareStatement(sql);
pst.setLong(1, key);
ResultSet rs = pst.executeQuery();
String sqlStatment = "SELECT * FROM " + tableName + " WHERE Patient_ID = ?";
PreparedStatement preparedStatement = conn.prepareStatement(sqlStatment);
preparedStatement.setint(1, patientId);
ResultSet resultSet = preparedStatement.executeQuery();
public void getByIdEmployer() throws SQLException {
Connection con = null;
try {
con = jdbcUtil.connectionDtls();
PreparedStatement ptst = con.prepareStatement(getById);
ptst.setInt(1, 4);
ResultSet res = ptst.executeQuery();
while (res.next()) {
int empid = res.getInt(1);
System.out.println(empid);
String name = res.getString(2);
System.out.println(name);
int salary = res.getInt(3);
System.out.println(salary);
String location = res.getString(4);
System.out.println(location);
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
con.close();
}
}