Develop Reference

java.sql.SQLException: No operations allowed after statement closed

I updated my database from SQLite db to MySQL and I suddenly I get this error:
java.sql.SQLException: No operations allowed after statement closed.
public boolean isEnough(int quantity, String item) throws SQLException {
boolean enough = false;
PreparedStatement pst = null;
ResultSet rs = null;
String sql = "SELECT * FROM Stock WHERE Item_name='" + item + "'";
pst = conn.prepareStatement(sql);
rs = pst.executeQuery();
if (rs.next()) {
int temp = rs.getInt(3);
if (quantity > temp) {
stmt.close();
enough = false;
} else if (quantity <= temp) {
enough = true;
int updatedStock = temp - quantity;
String sql_1 = "UPDATE Stock SET Item_quantity ='" + updatedStock + "' WHERE Item_name ='" + item + "'";
stmt.executeUpdate(sql_1); //error here
String sql_2 = "SELECT * FROM Stock WHERE Item_name='" + item + "'";
pst = conn.prepareStatement(sql);
rs = pst.executeQuery();
System.out.println(rs);
if (rs.next()) {
int isZero = rs.getInt(3);
if (isZero == 0) {
String sql_3 = "DELETE FROM Stock WHERE Item_name = '" + item + "'";
stmt.executeUpdate(sql_3);
JOptionPane.showMessageDialog(this, "Order Added\nItem is now out of Stock and removed from Stock database automatically.");
}
}
}
}
stmt.close();
return enough;
}
I'm closing connection and statement after every update, but I have no idea how to fix this error. If I go back to SQLite db this error disappears. I'm new to MySQL, so pardon me if I'm doing something wrong.

Java sql error when trying to update database

I am having a sql syntax issue when I am trying to update my databse through my update method which is trigured by a button
here is the button code
update.addActionListener(e -> {
int i = table.getSelectedRow();
if (i >= 0) {
model.setValueAt(PackId.getText(), i, 0);
model.setValueAt(PackName.getText(), i, 1);
model.setValueAt(VendorName.getText(), i, 2);
model.setValueAt(PackValue.getText(), i, 3);
try {
updatepacks(PackId,PackName,VendorName,PackValue);
} catch (SQLException throwables) {
throwables.printStackTrace();
}
} else {
System.out.println("Update Error");
}
The update method code
public void updatepacks(JTextField PackId, JTextField PackName, JTextField VendorName, JTextField PackValue) throws SQLException {
try{
Connection conn = DriverManager.getConnection("jdbc:sqlite:packsver3.db");
String sqlupdate = "Update packs" + " SET PackName = ?" + " VendorName = ?" + "PackValue = ? " + "Where PackId = ? ";
try (PreparedStatement ps = conn.prepareStatement(sqlupdate)) {
ps.setString(1, String.valueOf(PackId));
ps.setString(2, String.valueOf(PackName));
ps.setString(3, String.valueOf(VendorName));
ps.setString(4, String.valueOf(PackValue));
ps.executeUpdate();
}
} catch (Exception e) {
e.printStackTrace();
}
}
And the error

You missed the commas in the UPDATE statement. It should look like:
String sqlupdate = "Update packs"
+ " SET PackName = ?, " // added comma at the end
+ " VendorName = ?, " // added comma at the end
+ "PackValue = ? "
+ "Where PackId = ? ";

Unable to query database correctly using JDBC

I am trying to update a database using input from user and saving it in jtable, then using jtable I am updating the database, but I am not able to get fetch and update 2nd row in database.
please suggest a solution, Thanks in advance.
try {
Class.forName("com.mysql.jdbc.Driver");
con = myconnection.getConnection();
String name;
for (int i = 0; i < jTable2.getRowCount(); i++) {
name = (String) jTable2.getModel().getValueAt(i, 0);
String abcd = "select * from medicine where Name=? ";
stmt = conn.prepareStatement(abcd);
stmt.setString(1, name);
rs = stmt.executeQuery();
if (rs.next()) {
name = (String) jTable2.getModel().getValueAt(i, 0);
String stock = rs.getString("qty");
int nowstock = Integer.parseInt(stock);
int qty1 = Integer.parseInt(jTable2.getValueAt(i, 2).toString());
int newstock = nowstock - qty1;//Integer.parseInt(jTable2.getValueAt(i, 2).toString());
String sqlupdate = "UPDATE medicine SET qty='" + newstock + "'WHERE Name='" + name + "' "; //
stmt = conn.prepareStatement(sqlupdate);
stmt.executeUpdate();
}
}
} catch (ClassNotFoundException ex) {
Logger.getLogger(Bill.class.getName()).log(Level.SEVERE, null, ex);
} catch (SQLException ex) {
Logger.getLogger(Bill.class.getName()).log(Level.SEVERE, null, ex);
}

The select serves no purpose, and you can just iterate all names and update directly:
for (int i=0; i < jTable2.getRowCount(); i++) {
String name = (String) jTable2.getModel().getValueAt(i, 0);
int qty1 = Integer.parseInt(jTable2.getValueAt(i, 2).toString());
String update = "UPDATE medicine SET qty = qty - ? WHERE Name = ?";
PreparedStatement ps = conn.prepareStatement(update);
ps.setInt(1, qty1);
ps.setString(2, name);
ps.executeUpdate();
}
If your JTable happens to have more than say 10 or so names, then a more efficient way to do this would be to use a single update with a WHERE IN clause containing all names which appear in the table, i.e.
UPDATE medicine SET qty = qty - ? WHERE Name IN (...);

Not able to run executeUpdate()

I have been trying to insert data into DB using prepared statement but not able to run stmt.executeUpdate() The query will insert the field from the array which is declared below,The statement will set the values from the array.
long[] array = new long[100];
int[] devreg = new int[10];
int count = 0, index = 0;
try
{
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection(Constants.DB_URL, Constants.USER, Constants.PASS);
// LogMgr.dblogger.info(name +" : Database connection established"); //connection passed
}
catch (Exception e)
{
LogMgr.dblogger.info("Cannot connect to database" + e.toString()); //connection failure
}
if (conn != null) //if connection passed or available
{ //checking device registration
String InsertQuery = " INSERT INTO `acc_dev_db`.`widhb` (`name`,`age`, `type`) VALUES ";
int needacomma = 0;
for (int i=0; i< noofMsg; i++)
{
long empid = array[(i*indexlength)+1];
try
{
Statement s = conn.createStatement ();
s.executeQuery ("SELECT `empid` FROM `acc_dev_db`.`ID` WHERE `widevid` = "+empid+";");
ResultSet rs = s.getResultSet ();
if (rs.next())
{
devstatus = true;
if(needacomma>0)
{
InsertQuery = InsertQuery + ",";
}
InsertQuery = InsertQuery + "(?,?,?,?)";
needacomma += 1;
devreg[j] = i;
j++;
LogMgr.dblogger.info("ID found registered : " + empid); //found device id in the device table. Known device
}
else
{
LogMgr.dblogger.info("ID found not registered : " + empid);
}
rs.close ();
s.close ();
}
catch (Exception e) {
LogMgr.dblogger.info("Database reading error \n" + e.toString() ); //database reading error
}
}
if (devstatus == true) //if device is registered or known device
{
InsertQuery = InsertQuery + ";";
java.sql.PreparedStatement stmt = conn.prepareStatement(InsertQuery);
int loc = 1;
for (count = 0;count < j; count++)
{
int position = (indexlength*devreg[count]);
stmt.setLong(loc, array[position]);
System.out.println( array[position]);
stmt.setDouble(loc + 1, array[position + 1]);
System.out.println( array[position+1]);
stmt.setTimestamp(loc + 2,dateconvert(2, array[position + 2]));
System.out.println( array[position+2]);
stmt.setLong(loc + 3, array[position + 3]);
System.out.println( array[position+3]);
loc += 4;
}
LogMgr.jmslogger.info(stmt.toString());
try{
stmt.executeUpdate();
LogMgr.dblogger.info(name +" : studentdata update successfull from dev : " + devaddress);
}
catch(SQLException e){
System.out.println("EXCEPTION MAN!!!");
}
conn.close ();
}
Current O/P:
12355419
3740073994
491504582
43690
EXCEPTION MAN!!!

You Should throw SqlException or use try-catch block and for manage SqlException

Getting SQL error 1078 Before start of result set in Java program [duplicate]

This question already has answers here:
ResultSet exception - before start of result set
(6 answers)
Closed 5 years ago.
I have a Java method that is supposed to get column values from one MySQL row and create a string with the values. When run, it generates a SQL error 1078 "Before start of result set."
Here is the the class in which the error is occuring (Problem is in listPosesInSection method:
/** Class used to access the database */
import java.sql.*;
import java.util.ArrayList;
import javax.swing.JOptionPane;
public class YogaDatabaseAccess {
String dbUrl = "jdbc:mysql://localhost/yoga";
private Connection connection;
private ResultSet rset;
private ResultSetMetaData rsMetaData;
private Statement statement;
private PreparedStatement pStatementAll = null;
private PreparedStatement pStatementPartial = null;
// Strings for queries and updates
String strListPosesNotPrimary;
String strInsertNewClass;
String strInsertNewSection;
String strInsertNewPose;
String strUpdateClass;
String strUpdateSection;
String strUpdatePose;
String strArrangePoseOrder;
private String[] poseArray;
// Constructor
YogaDatabaseAccess() {
connectToDatabase();
}
// Method that connects to database
private void connectToDatabase() {
try {
connection = DriverManager.getConnection(dbUrl, "Kyle", "Kullerstrand#2");
System.out.println("Database connected");
}
catch(SQLException e) {
System.out.println(e.getMessage());
}
}
// Query that returns lists to be used with combo boxes
public String listForBoxes(String listName) {
// List to be returned
String strList = "";
// Determine name of the database table for this list
String listTableName;
if (listName == "pose")
listTableName = listName + "s";
else if (listName == "class")
listTableName = listName + "es";
else
listTableName = listName;
// Determine the database column name for this list
String listColumnName = listName + "_name";
// Run the query
try {
statement = connection.createStatement();
rset = statement.executeQuery("SELECT DISTINCT " + listColumnName + " FROM " + listTableName +
" ORDER BY " + listColumnName);
while (rset.next()){
strList = strList + rset.getString(listColumnName) + ", ";
}
} catch (SQLException e) {
e.printStackTrace();
}
return strList;
}
// Query that returns list of primary poses for a section
public String listPrimaryPoses(String sectionName) {
// List to be returned
String strList = "";
// Run the query
try {
statement = connection.createStatement();
rset = statement.executeQuery("SELECT DISTINCT pose_name FROM poses WHERE primarily_suitable_for = '" + sectionName +
"' OR primarily_suitable_for = 'Anything' ORDER BY pose_name");
while (rset.next()){
strList = strList + rset.getString("pose_name") + ", ";
}
} catch (SQLException e) {
e.printStackTrace();
}
return strList;
}
// Query that returns list of secondary poses for a section
public String listSecondaryPoses(String sectionName) {
// List to be returned
String strList = "";
// Run the query
try {
statement = connection.createStatement();
rset = statement.executeQuery("SELECT DISTINCT pose_name FROM poses WHERE sometimes_suitable_for = '" + sectionName + "' ORDER BY pose_name");
while (rset.next()){
strList = strList + rset.getString("pose_name") + ", ";
}
} catch (SQLException e) {
e.printStackTrace();
}
return strList;
}
// Query that returns the poses within a specific section
public String listPosesInSection(String tableName, String sectionName) {
String strList;
StringBuilder strBuilderList = new StringBuilder("");
// Run the query
try {
statement = connection.createStatement();
// Query will collect all columns from one specific row
rset = statement.executeQuery("SELECT * FROM " + tableName + " WHERE " + tableName + "_name = '" + sectionName + "'");
while (rset.next()) {
for (int i = 2; i <= countColumnsInTable(tableName); i++) // First value (0) is always null, skip section name (1)
if (rset.getString(i) != null) // If column has a value
strBuilderList.append(rset.getString(i) + "\n");
}
} catch (SQLException e) {
e.printStackTrace();
}
strList = strBuilderList.toString();
return strList.replaceAll(", $",""); // Strips off the trailing comma
}
// Insert statement that inserts a new class into the classes table
public void insertNewClass(String className) {
/** String insert = "INSERT INTO poses (pose_name, primarily_suitable_for, sometimes_suitable_for) values(?, ?, ?)";
System.out.println("About to create the prepared statement");
// Run the insert
try {
pStatement = connection.prepareStatement(insert);
// statement.execute("INSERT IGNORE INTO poses VALUES ('" + poseName + "', '" + suitableFor + "', '" + suitableForSometimes + "')");
pStatement.setString(1, poseName);
pStatement.setString(2, suitableFor);
pStatement.setString(3, suitableForSometimes);
System.out.println("Created the prepared statement");
// execute query, and return number of rows created
pStatement.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
} */
}
// Insert statement that inserts a new pose into poses table
public void insertNewPose(String poseName, String suitableFor, String suitableForSometimes) {
String insertAll = "INSERT INTO poses (pose_name, primarily_suitable_for, sometimes_suitable_for) values(?, ?, ?)";
String insertPartial = "INSERT INTO poses (pose_name, primarily_suitable_for) values(?, ?)";
// Run the insert
try {
if (suitableForSometimes == "NULL") { // Insert statement contains a null value for sometimes suitable column
pStatementPartial = connection.prepareStatement(insertPartial);
pStatementPartial.setString(1, poseName);
pStatementPartial.setString(2, suitableFor);
pStatementPartial.executeUpdate();
} else { // Insert statement contains values for all three columns
pStatementAll = connection.prepareStatement(insertAll);
pStatementAll.setString(1, poseName);
pStatementAll.setString(2, suitableFor);
pStatementAll.setString(3, suitableForSometimes);
pStatementAll.executeUpdate();
}
} catch (SQLException e) {
System.err.println("SQLException: " + e.getMessage() + ":" + e.getSQLState());
JOptionPane.showMessageDialog(null, "This pose already exists.");
} finally {
SQLWarning w;
try {
for (w = connection.getWarnings(); w != null; w = w.getNextWarning())
System.err.println("WARNING: " + w.getMessage() + ":" + w.getSQLState());
} catch (SQLException e) {
e.printStackTrace();
JOptionPane.showMessageDialog(null, "An unknown error in the yoga design program has occurred.");
}
}
}
// Insert statement that inserts a new section into warmup, work or restore sections
public void insertNewSection(String sectionType, String sectionName, ArrayList<String> poses) {
System.out.println("insertNewSection method was called");
int maxColumns = countColumnsInTable(sectionType);
poseArray = new String[poses.size()];
poseArray = poses.toArray(poseArray);
if (poseArray.length == 0)
JOptionPane.showMessageDialog(null, "There are no poses in this section. Please add poses.");
// Create a list of columns of the table for the INSERT statement
StringBuilder columns = new StringBuilder(sectionType + "_name");
for (int c = 1; c < maxColumns; c++)
columns.append(", pose_" + c);
// Create a string list of poses, separated by commas, from the array
StringBuilder values = new StringBuilder();
values.append("'" + poseArray[0] + "'");
for (int v = 1; v < poseArray.length - 1; v++)
values.append(", '" + poseArray[v] + "'");
// make sure query uses correct number of columns by padding the query with NULL
for (int i = poseArray.length; i < maxColumns; i++)
values.append(", NULL");
String posesToAddToSection = values.toString();
// The string containing the entire insert statement
String insert = "INSERT INTO " + sectionType + " (" + columns + ") VALUES ('" + sectionName + "', " + posesToAddToSection + ")";
// Run the insert
try {
statement = connection.createStatement();
statement.executeUpdate(insert);
} catch (SQLException e) {
System.err.println("SQLException: " + e.getMessage() + ":" + e.getSQLState());
JOptionPane.showMessageDialog(null, "An error in the yoga design program has occurred. SQLException: " +
e.getMessage() + ":" + e.getSQLState());
} finally {
SQLWarning w;
try {
for (w = connection.getWarnings(); w != null; w = w.getNextWarning())
System.err.println("WARNING: " + w.getMessage() + ":" + w.getSQLState());
} catch (SQLException e) {
e.printStackTrace();
JOptionPane.showMessageDialog(null, "An unknown error in the yoga design program has occurred.");
}
}
}
// Statement that deletes rows from tables
public void deleteRow(String tableName, String columnName, String rowName) {
String delete = "DELETE FROM " + tableName + " WHERE " + columnName + " = '" + rowName + "'";
// Run the insert
try {
statement = connection.createStatement();
statement.executeUpdate(delete);
System.out.println("Delete statement was run on Java's end.");
} catch (SQLException e) {
System.err.println("SQLException: " + e.getMessage() + ":" + e.getSQLState());
JOptionPane.showMessageDialog(null, "Sorry, something went wrong: SQLException: " +
e.getMessage() + ":" + e.getSQLState());
} finally {
SQLWarning w;
try {
for (w = connection.getWarnings(); w != null; w = w.getNextWarning())
System.err.println("WARNING: " + w.getMessage() + ":" + w.getSQLState());
} catch (SQLException e) {
e.printStackTrace();
}
}
}
// Method for getting the number of columns in a table using metadata
public int countColumnsInTable(String sectionType) {
int count = 16;
try {
// System.out.println(sectionType);
statement = connection.createStatement();
rset = statement.executeQuery("SELECT * FROM " + sectionType);
rsMetaData = rset.getMetaData();
count = rsMetaData.getColumnCount();
// System.out.println("Column count is " + count);
} catch (SQLException e) {
e.printStackTrace();
}
return count;
}
// Close the database and release resources
public void closeDatabase() {
try {
connection.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
And here is the beginning of the error list:
java.sql.SQLException: Before start of result set
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1078)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:989)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:975)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:920)
at com.mysql.jdbc.ResultSetImpl.checkRowPos(ResultSetImpl.java:855)
at com.mysql.jdbc.ResultSetImpl.getStringInternal(ResultSetImpl.java:5773)
at com.mysql.jdbc.ResultSetImpl.getString(ResultSetImpl.java:5693)
at YogaDatabaseAccess.listPosesInSection(YogaDatabaseAccess.java:125)
at YogaSectionDesigner$5.actionPerformed(YogaSectionDesigner.java:229)

May be you can check this out:
ResultSet exception - before start of result set
Had the same Problem. Solved it that way.