Develop Reference

Java JDBC SQLite database locked by a select with where clause

I'm calling this method:
ArrayList<String> selectFilteredJump(String owner, String fromDate, String toDate, String env) {
ArrayList<String> a = new ArrayList<>();
Connection c;
Statement stmt;
StringBuilder whereClause = new StringBuilder("WHERE a.Date BETWEEN '"+fromDate+ "' and '" + toDate+"'");
if (!env.equals(constants.EMPTY) ) {
whereClause.append(" and a.Environment = '").append(env).append("'");
}
if (!owner.equals(constants.EMPTY) ) {
whereClause.append(" and a.UserId = '").append(owner).append("'");
}
String sql = "SELECT a.TicketID, a.Subject, a.UserID, a.Date, a.Solution, a.Comments," +
"a.Environment, (SELECT UserName FROM Users WHERE UserID = a.UserID) AS UserName FROM Tickets a " +
whereClause + " order by 4 asc;";
System.out.println(sql);
try {
Class.forName("org.sqlite.JDBC");
c = DriverManager.getConnection("jdbc:sqlite:" + this.dbPath + this.dbName) ;
c.setAutoCommit(false);
stmt = c.createStatement();
ResultSet rs = stmt.executeQuery(sql);
while (rs.next()) {
a.add(rs.getString("TicketID"));
a.add(rs.getString("Subject"));
a.add(rs.getString("UserID"));
a.add(rs.getString("Date"));
a.add(rs.getString("Solution"));
a.add(rs.getString("Comments"));
a.add(rs.getString("Environment"));
a.add(rs.getString("UserName"));
}
rs.close();
stmt.close();
c.close();
}
catch (Exception e) {
System.err.println(e.getClass().getName() + ": " + e.getMessage());
}
return a;
}
Everything executes correctly but it seems that my database remains locked with no visible reason.
On the other side if I'm replacing with this method the database is ok after executing it:
ArrayList<String> selectAllJump() {
if (constants.DEBUG_MODE) System.out.println("selectAllJump");
ArrayList<String> a = new ArrayList<>();
Connection c;
Statement stmt;
try {
Class.forName("org.sqlite.JDBC");
c = DriverManager.getConnection("jdbc:sqlite:" + this.dbPath + this.dbName);
c.setAutoCommit(false);
stmt = c.createStatement();
ResultSet rs = stmt.executeQuery("SELECT a.TicketID, a.Subject, a.UserID, a.Date, a.Solution, a.Comments," +
"a.Environment, (SELECT UserName FROM Users WHERE UserID = a.UserID) AS UserName FROM Tickets a " +
"order by 4 asc;");
while (rs.next()) {
a.add(rs.getString("TicketID"));
a.add(rs.getString("Subject"));
a.add(rs.getString("UserID"));
a.add(rs.getString("Date"));
a.add(rs.getString("Solution"));
a.add(rs.getString("Comments"));
a.add(rs.getString("Environment"));
a.add(rs.getString("UserName"));
}
rs.close();
stmt.close();
c.close();
}
catch (Exception e) {
System.err.println(e.getClass().getName() + ": " + e.getMessage());
}
return a;
}
I've also tried to open the connection using specific configuration (like this):
c = DriverManager.getConnection("jdbc:sqlite:" + this.dbPath + this.dbName,setConfig().toProperties()) ;
private SQLiteConfig setConfig() {
SQLiteConfig config = new SQLiteConfig();
config.enforceForeignKeys(true);
config.setTempStore(SQLiteConfig.TempStore.MEMORY);
config.setCacheSize(1000);
config.setReadOnly(true);
return config;
}
and still the same error:
org.sqlite.SQLiteException: [SQLITE_BUSY] The database file is locked (database is locked)
Any idea is welcomed.
Thank you.

Error when trying to insert new data into sql databse in java

I am trying to insert new data in a SQL database using a DAO. I have a boolean method for insert but there is a SQL error or database is missing. Database is not missing because I tested it and it displays everything from the table.
Here is the connection method
public Connection getDBConnection() {
Connection dbConnection = null;
try {
Class.forName("org.sqlite.JDBC");
} catch (ClassNotFoundException e) {
System.out.println(e.getMessage());
}
try {
String dbURL = "jdbc:sqlite:studentdb.sqlite";
dbConnection = DriverManager.getConnection(dbURL);
return dbConnection;
} catch (SQLException e) {
System.out.println(e.getMessage());
}
return dbConnection;
}
And the insert method
public boolean insertStu(Student stu) throws SQLException {
Connection dbConnection = null;
Statement statement = null;
ResultSet resultset = null;
boolean b = false;
try {
String query = "insert into studentdb (Name, Gender, DOB, Address, Postcode, StudentNumber, CourseTitle, StartDate, Bursary, Email) values (\""
+ stu.getName() + "\"," + "\"" + stu.getGender() + "\"," + "\"" + stu.getDob() + "\"," + "\""
+ stu.getAddress() + "\"," + "\"" + stu.getPostcode() + "\"," + "\"" + stu.getStudentNumber()
+ "\"," + "\"" + stu.getCourseTitle() + "\"," + "\"" + stu.getStartDate() + "\"," + "\""
+ stu.getBursary() + "\"," + "\"" + stu.getEmail() + "\")";
dbConnection = getDBConnection();
statement = dbConnection.createStatement();
b = statement.execute(query);
} catch (SQLException s) {
throw new SQLException("Contact Not Added");
} finally {
if (dbConnection != null) {
dbConnection.close();
}
if (statement != null) {
statement.close();
}
if (resultset != null){
resultset.close();
}
}
return b;
}
I have tried the SQL query in different program where the connection method was Statement type and the insert method was still boolean but now the requirement is to use Connection class. Either way it should work but I don't understand way is not working. The Student object has get and set methods for its variables.
Any help would be much appreciated.

Sending data by JDBC, strange case with StrictMode

My method working only with StrictMode, when i delete StrictMode, my app after the run this method loading in the infinity... and never stop.
I don't know why, somebody can explain it ?
public void sending() {
Connection co = null;
Statement st = null;
try {
StrictMode.ThreadPolicy po = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(po);
Class.forName("com.mysql.jdbc.Driver");
co = DriverManager.getConnection(url2, user2, pass2);
st = co.createStatement();
Double bb = latitude;
Double bb1 = longitude;
String sql2 = "INSERT table (tab1, tab2) VALUES('" + bb + "', '" + bb1 + "')";
st.executeUpdate(sql2);
} catch (SQLException se) {
se.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (st != null) {
co.close();
}
} catch (SQLException se) {
}
try {
if (co != null) {
co.close();
}
} catch (SQLException se) {
se.printStackTrace();
}
}
}

Your have a problem in your Query it should be :
"INSERT Into table (tab1, tab2) VALUES('" + bb + "', '" + bb1 + "')"
and not :
"INSERT table (tab1, tab2) VALUES('" + bb + "', '" + bb1 + "')"
You missed Into in your query.
Note
You can get syntax error or Sql injection with your way i suggest to use PreparedStatement it's more secure and more helpful like this :
PreparedStatement preparedStatement =
connection.prepareStatement("INSERT into table (tab1, tab2) VALUES(?, ?)");
preparedStatement.setString(1, bb);
preparedStatement.setString(2, bb1);

Database locked SQLite Java

I'm making some programme for checking approaches scales for different usernames. When I call function DodajObrisiPristupe(table, comboBox), it says database locked. I searched for solutions and all says that it's probably that I didn't close connection somewhere, but I can't find where. Can anyone please help me?
public void DodajObrisiPristupe(JTable tabela, JComboBox<String> korisnickoime)
{
DefaultTableModel model = (DefaultTableModel)tabela.getModel();
for (int i = 0; i < model.getRowCount(); i++)
{
String serijskibroj = model.getValueAt(i, 2).toString();
boolean pristup = (Boolean)model.getValueAt(i, 4);
if(ProveriDaLiPostojiPristup(serijskibroj, korisnickoime.getSelectedItem().toString()) == true)
{
if(pristup == false)
ObrisiPristup(serijskibroj, korisnickoime.getSelectedItem().toString());
}
else
{
if(pristup == true)
DodajPristup(serijskibroj, korisnickoime.getSelectedItem().toString());
}
}
}
public boolean ProveriDaLiPostojiPristup(String serijskibroj, String korisnickoime)
{
Connection c = null;
Statement stmt = null;
try {
Class.forName("org.sqlite.JDBC");
c = DriverManager.getConnection("jdbc:sqlite:" + naziv + ".db");
stmt = c.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * FROM PRISTUPI;");
while(rs.next())
{
if(Decrypt(rs.getString("korisnickoime")).equals(korisnickoime) && Decrypt(rs.getString("vage")).equals(serijskibroj))
return true;
}
rs.close();
stmt.close();
c.close();
}
catch ( Exception e ) {
System.err.println( e.getClass().getName() + ": " + e.getMessage() );
System.exit(0);
}
return false;
}
public void DodajPristup(String serijskibroj, String korisnickoime)
{
Connection c = null;
Statement stmt = null;
try {
Class.forName("org.sqlite.JDBC");
c = DriverManager.getConnection("jdbc:sqlite:" + naziv + ".db");
stmt = c.createStatement();
String sql = "INSERT INTO PRISTUPI (KORISNICKOIME,VAGE) " +
"VALUES ('" + Encrypt(korisnickoime) + "', '" + Encrypt(serijskibroj) + "');";
stmt.executeUpdate(sql);
stmt.close();
c.close();
}
catch ( Exception e ) {
System.err.println( e.getClass().getName() + ": " + e.getMessage() );
System.exit(0);
}
}
public void ObrisiPristup(String serijskibroj, String korisnickoime)
{
Connection c = null;
Statement stmt = null;
try {
Class.forName("org.sqlite.JDBC");
c = DriverManager.getConnection("jdbc:sqlite:" + naziv + ".db");
stmt = c.createStatement();
String sql = "DELETE from PRISTUPI where KORISNICKOIME = '" + Encrypt(korisnickoime) + "' AND VAGE = '" + Encrypt(serijskibroj) + "';";
stmt.executeUpdate(sql);
stmt.close();
c.close();
}
catch ( Exception e ) {
System.err.println( e.getClass().getName() + ": " + e.getMessage() );
System.exit(0);
}
}

You are not closing your connection in ProveriDaLiPostojiPristup(String, String).
You should always wrap your connections in try-with-resources or try-finaly, so they are always closed.
c = DriverManager.getConnection("jdbc:sqlite:" + naziv + ".db");
stmt = c.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * FROM PRISTUPI;");
while(rs.next())
{
if(Decrypt(rs.getString("korisnickoime")).equals(korisnickoime) &&
Decrypt(rs.getString("vage")).equals(serijskibroj))
return true;
}
rs.close();
stmt.close();
c.close();
What happens, is that your method returns true, but because the execution is stopped there, it won't execute the lines below it. This can be countered if you wrap the statements in a try with resources block:
try(c = DriverManager.getConnection("jdbc:sqlite:" + naziv + ".db")){
try(stmt = c.createStatement()){
try(ResultSet rs = stmt.executeQuery("SELECT * FROM PRISTUPI;")){
while(rs.next())
{
if(Decrypt(rs.getString("korisnickoime")).equals(korisnickoime) && Decrypt(rs.getString("vage")).equals(serijskibroj))
return true;
}
}
}
}

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.