When I am trying to print the row values from a table in a PostgreSQL database using JDBC with this code
static Connection c = null;
static Statement statement = null;
static Scanner sc = new Scanner(System.in);
public static void displayTable() throws Exception{
ResultSet rs = statement.executeQuery("SELECT * FROM TABLE");
String dataBaseName = "";
String dataBaseNumber = "";
try {
while(rs.next()){
//System.out.println("Resultant set: " + rs);
dataBaseName = rs.getString("name");
dataBaseNumber = rs.getString("number");
System.out.println("Name: " + dataBaseName + "\Number: " + dataBaseNumber);
}
} catch (Exception e) {
System.out.println(e);
}
}
In while loop, after printing first row it gives me exception
org.postgresql.util.PSQLException: This ResultSet is closed.
Can some one please explain what's going on?
Related
i am working with Jena Text Search using SPARQL. It has succeed in compile time and run time but it doesn't show the desired result which is the result should show the URI and the intended text. It looks like error messages but i get the failed description below:
DEBUG org.apache.jena.util.LocationMapper - Failed to find configuration: file:location-mapping.rdf;file:location-mapping.n3;file:location-mapping.ttl;file:etc/location-mapping.rdf;file:etc/location-mapping.n3;file:etc/location-mapping.ttl
DEBUG org.apache.jena.riot.system.stream.JenaIOEnvironment - Failed to find configuration: location-mapping.ttl;location-mapping.rdf;location-mapping.n3;etc/location-mapping.rdf;etc/location-mapping.n3;etc/location-mapping.ttl
The full codes show below:
public class JenaTextSearch {
static {LogCtl.setLog4j();
BasicConfigurator.configure();}
static Logger log = LoggerFactory.getLogger("JenaTextSearch");
public static void main (String ...argv)
{
Dataset ds = createCode();
//loadData(ds, "data.ttl");
queryData(ds);
}
public static Dataset createCode()
{
//base data
Dataset ds1 = DatasetFactory.create();
Model defaultModel = ModelFactory.createDefaultModel();
defaultModel.read("to_index/data.ttl", "N-TRIPLES");
ds1.setDefaultModel(defaultModel);
//define the index mapping
EntityDefinition entDef = new EntityDefinition ("uri", "text", ResourceFactory.createProperty(App.URI_PREFIX,"content"));
Directory dir = null;
try {
dir = new SimpleFSDirectory(Paths.get("index")); //lucene index directory
}
catch (IOException e) {
e.printStackTrace();
}
//join together into a dataset
Dataset ds = TextDatasetFactory.createLucene(ds1, dir, new TextIndexConfig(entDef));
return ds1;
}
public static void queryData(Dataset dataset)
{
String prefix = "PREFIX email: <" + App.URI_PREFIX+">" +
"PREFIX text: <http://jena.apache.org/text#>";
long startTime = System.nanoTime();
System.out.println("Email's content contains 'good'");
String query = "SELECT * WHERE " +
"{?s text:query (email:content 'good')." +
"?s email:content ?text." +
"}" ;
dataset.begin(ReadWrite.READ);
try {
Query q = QueryFactory.create(prefix+"\n"+query);
QueryExecution qexec = QueryExecutionFactory.create(q, dataset);
QueryExecUtils.executeQuery(q, qexec);
}finally { dataset.end();}
long finishTime = System.nanoTime();
double time = (finishTime-startTime)/1.0e6;
System.out.println ("Query "+String.format("FINISH - %.2fms", time));
startTime = System.nanoTime();
System.out.println("Email's content contains 'bad'");
query = "SELECT * WHERE" +
"{(?s ?score ?lit) text:query (email:content 'bad' \"highlight:s:<em class='hiLite'> | e:</em>\")." +
"?s email:content ?text." +
"}" ;
dataset.begin(ReadWrite.READ);
try {
Query q = QueryFactory.create(prefix+"\n"+query);
QueryExecution qexec = QueryExecutionFactory.create(q, dataset);
QueryExecUtils.executeQuery(q, qexec);
} finally { dataset.end() ; }
finishTime = System.nanoTime();
time = (finishTime-startTime)/1.0e6;
System.out.println("Query "+String.format("FINISH - %.2fms", time));
}}
is that a library problem or something? i use Jena 3.9 and 3.13 because it can completely each other, i think. please devise me. thank you.
I need to implement an update of the database lying in the assets. User data, namely, in the "favorite" record or not, should be saved.
I already asked a question and they helped me -https://stackoverflow.com/a/53827525/10261947
Everything worked in a test application. But when I transferred the code (exactly the same) to the real application, an error occurs - E/AndroidRuntime: FATAL EXCEPTION: ModernAsyncTask #1
Process: rodionova.lyubov.brodsky, PID: 4196
java.lang.RuntimeException: An error occurred while executing doInBackground()
at android.support.v4.content.ModernAsyncTask$3.done(ModernAsyncTask.java:161)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:383)
at java.util.concurrent.FutureTask.setException(FutureTask.java:252)
at java.util.concurrent.FutureTask.run(FutureTask.java:271)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636)
at java.lang.Thread.run(Thread.java:784)
Caused by: java.lang.IllegalArgumentException: the bind value at index 4 is null
at android.database.sqlite.SQLiteProgram.bindString(SQLiteProgram.java:169)
at android.database.sqlite.SQLiteProgram.bindAllArgsAsStrings(SQLiteProgram.java:205)
at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:47)
at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1397)
at android.database.sqlite.SQLiteDatabase.queryWithFactory(SQLiteDatabase.java:1239)
at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1110)
at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1278)
at rodionova.lyubov.brodsky.db.PoemsDbHelper.insertCorePoem(PoemsDbHelper.java:121)
at rodionova.lyubov.brodsky.db.PoemsDbHelper.getNewPoems(PoemsDbHelper.java:90)
at rodionova.lyubov.brodsky.db.PoemsDbHelper.onUpgrade(PoemsDbHelper.java:41)
at com.readystatesoftware.sqliteasset.SQLiteAssetHelper.getWritableDatabase(SQLiteAssetHelper.java:197)
at com.readystatesoftware.sqliteasset.SQLiteAssetHelper.getReadableDatabase(SQLiteAssetHelper.java:254)
at rodionova.lyubov.brodsky.db.PoemsProvider.query(PoemsProvider.java:45)
at android.content.ContentProvider.query(ContentProvider.java:1057)
If you do not perform the update, the application is working properly, so I will post only the code DbHelper
public class PoemsDbHelper extends SQLiteAssetHelper {
public static final String DB_NAME = "brodsky.db";
public static final int DBVERSION = 3;
public static final String TBLNAME = "poems_table";
public static final String COL_ID = "id";
public static final String COL_TITLE = "title";
public static final String COl_POEM = "poem";
public static final String COL_SUBJECT = "subject";
public static final String COL_YEARS = "years";
public static final String COL_FAVOURITE = "favorite";
Context mContext;
public PoemsDbHelper(Context context) {
super(context, DB_NAME, null, DBVERSION);
mContext = context;
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
if(newVersion > oldVersion)
getNewPoems(mContext, db);
}
private void getNewPoems(Context context, SQLiteDatabase db) {
InputStream is;
OutputStream os;
final String tempNewDbName = "temp_brodsky.db";
int buffersize = 4096;
byte[] buffer = new byte[buffersize];
String newDBPath = mContext.getDatabasePath(tempNewDbName).getPath();
File newDBFile = new File(newDBPath);
if (newDBFile.exists()) {
newDBFile.delete();
}
File newDBFileDirectory = newDBFile.getParentFile();
if (!newDBFileDirectory.exists()) {
newDBFileDirectory.mkdirs();
}
try {
is = context.getAssets().open("databases/" + DB_NAME);
os = new FileOutputStream(newDBFile);
int bytes_read;
while ((bytes_read = is.read(buffer,0,buffersize)) > 0) {
os.write(buffer);
}
os.flush();
os.close();
is.close();
}catch (IOException e) {
e.printStackTrace();
throw new RuntimeException("Ouch updated database not copied - processing stopped - see stack-trace above.");
}
long id = maxid(db) + 1;
SQLiteDatabase newdb = SQLiteDatabase.openDatabase(newDBFile.getPath(),null,SQLiteDatabase.OPEN_READONLY);
Cursor csr = newdb.query(TBLNAME,null,null,null,null,null,null);
long insert_result;
db.beginTransaction();
while (csr.moveToNext()) {
insert_result = insertCorePoem(
db,
id,
csr.getString(csr.getColumnIndex(COL_TITLE)),
csr.getString(csr.getColumnIndex(COl_POEM)),
csr.getString(csr.getColumnIndex(COL_SUBJECT)),
csr.getString(csr.getColumnIndex(COL_YEARS)),
csr.getString(csr.getColumnIndex(COL_FAVOURITE))
);
if (insert_result > 0) {
id++;
}
}
db.setTransactionSuccessful();
db.endTransaction();
csr.close();
newDBFile.delete();
}
public long insertCorePoem(SQLiteDatabase db, long id, String title, String poem, String subject, String years, String favourite) {
String whereclause = COL_TITLE + "=? AND " + COl_POEM + "=? AND " + COL_SUBJECT + "=? AND " + COL_YEARS + "=?";
String[] whereargs = new String[]{
title,
poem,
subject,
years
};
Cursor csr = db.query(TBLNAME,null,whereclause,whereargs,null,null,null);
boolean rowexists = (csr.getCount() > 0);
csr.close();
if (rowexists) {
Log.d("INSERTCOREPOEM","Skipping insert of row");
return -2;
}
ContentValues cv = new ContentValues();
cv.put(COL_ID,id);
cv.put(COL_TITLE,title);
cv.put(COl_POEM,poem);
cv.put(COL_SUBJECT,subject);
cv.put(COL_YEARS,years);
cv.put(COL_FAVOURITE,favourite);
Log.d("INSERTCOREPOEM","Inserting new column with id " + String.valueOf(id));
return db.insert(TBLNAME, null, cv);
}
private long maxid(SQLiteDatabase db) {
long rv = 0;
String extractcolumn = "maxid";
String[] col = new String[]{"max(" + COL_ID + ") AS " + extractcolumn};
Cursor csr = db.query(TBLNAME,col,null,null,null,null,null);
if (csr.moveToFirst()) {
rv = csr.getLong(csr.getColumnIndex(extractcolumn));
}
csr.close();
return rv;
}
}
I do not understand what is wrong. Identical code works great friend application. I would be grateful for the help.
Your issue is that you likely have a value of null in the years column of a row or rows in the updated database that data is being copied from.
Although you could change the code to handle (skip insertion or use provide a year value) the end result may not be desired. So the most likely fix would be to amend the database to have valid/useful year values.
I am trying to connect sql anywhere12 database to my .net project but while connecting to the database i am facing an error
"{"Invalid connection string. Error parsing connection parameter string\r\nParameter name: connectionString"}"
while running this code.
private void btncon_Click(object sender, EventArgs e)
{
string connetionString = null;
SAConnection connection;
SACommand command;
string sqla = null;
// connetionString = "Data Source=SQL Anywhere 12 Demo;Initial Catalog=Demo2;User ID=dba;Password=sql";
connetionString = "Driver={SQL Anywhere 12};ENG=demo12;UID=dba;PWD=sql;DBN=sql;LINKS=TCPIP(HOST=localhost)";
sqla = "INSERT INTO student(Rollnumber,Name) values('" + textBox1.Text + "','" + textBox2.Text + "')";
connection = new SAConnection(connetionString);
try
{
connection.Open();
command = new SACommand(sqla, connection);
command.ExecuteNonQuery();
command.Dispose();
connection.Close();
MessageBox.Show(" ExecuteNonQuery in SqlCommand executed !!");
}
catch (Exception ex)
{
MessageBox.Show("Can not open connection ! ");
}
}
actually i have no much knowledge about the sql anywhere 12 connection string please help me to solve this error
We are using java jdk 1.7.0_45, postgresql jdbc connector postgresql-9.3-1100.jdbc41.jar.
Here is a synopsis of our problem, as much as possible of code pasted below.
This code:
ResultSet rs = DbConn.getInstance().doQuery("Select d.deptId from Depts d");
while (rs.next()){
System.out.println(rs.getInt("d.deptId"));
Produces the error:
org.postgresql.util.PSQLException: The column name d.deptId was not found in this ResultSet.
This code:
ResultSet rs = DbConn.getInstance().doQuery("Select d.deptId from Depts d");
while (rs.next()){
System.out.println(rs.getInt("deptId"));
Produces no error.
Is there a way, besides removing the "d." from the first query, to make the first code snippet not throw the error message?
Here is the source code:
public class JoinTest {
#Test
public void test(){
boolean pass = false;
try {
ResultSet rs = DbConn.getInstance().doQuery("Select d.deptId from Depts d");
String label = rs.getMetaData().getColumnLabel(1); // What do you get?
System.out.println("label = " + label);
while (rs.next()){
System.out.println(rs.getInt("d.deptId"));
pass = true;
}
} catch (SQLException e) {
e.printStackTrace();
pass=false;
}
assertTrue(pass);
}
#Test
public void test2(){
boolean pass = false;
try {
ResultSet rs = DbConn.getInstance().doQuery("Select d.deptId from Depts d");
while (rs.next()){
System.out.println(rs.getInt("deptId"));
pass = true;
}
} catch (SQLException e) {
e.printStackTrace();
pass=false;
}
assertTrue(pass);
}
}
public class DbConn {
private static String url = "jdbc:postgresql://server:port/schema";
private static Properties props = new Properties(); {
props.setProperty("user","userid");
props.setProperty("password","passwprd");
}
private Connection conn;
private DbConn(){}
private static DbConn instance;
public static DbConn getInstance() throws SQLException{
if (instance == null){
instance = new DbConn();
instance.conn = DriverManager.getConnection(url, props);
}
return instance;
}
public ResultSet doQuery(String query) throws SQLException{
Logger.log("DbConn.doQuery: " + query);
Statement st = conn.createStatement();
ResultSet rs = st.executeQuery(query);
return rs;
}
}
}
The query:
select d.deptId from Depts d
produces a single-column resultset with the result-alias "deptId". There is no "d.deptId" column. If you want one, you can request that as the column alias instead:
select d.deptId AS "d.deptId" from Depts d
PgJDBC can't do anything about this because it has no idea that the resultset column "deptId" is related to the "d.deptId" in the select-list. Teaching it about that would force it to understand way more about the SQL it processes than would be desirable, and lead to maintenance and performance challenges.
The second one works - why isn't that acceptable?
You can also do this:
System.out.println(rs.getInt(1));
If you change the query you have to change the code, too.
I have two table related by foreign and primary key constraint.The Visit_Number in Patient table must exist in the Visit table.In my code in define create two instance of my connection string such that i can use one instance to insert record:VisitNumber in Visit table first and then the other instance to insert record in the patient table,with the believe that the cord runs from top to bottom.But this was n't the case. i still get foreign key constraint errror:
Error Number:547
Error MessageThe INSERT statement conflicted with the FOREIGN KEY constraint "Patient_Vist_FK".
The conflict occurred in database "TestDB", table "dbo.Visit", column 'Visit_Number'.
The statement has been terminated.On line Number: 1
meaning the code is running as i expected. Please do you have a better approach and why isn't mine working
code:
protected void btn_save_Click(object sender, EventArgs e)
{
string connect = System.Configuration.ConfigurationManager.ConnectionStrings["db_connection"].ToString();
SqlConnection con = new SqlConnection(connect);
SqlConnection con2 = new SqlConnection(connect);
string visitnumber = txtVistNumber.Text.ToString();
string insert_statement = "Insert into Patient(Patient_Number,FirstName,LastName,Gender,Tribe,Date_Of_Birth,Visit_Number)"
+ "Values(#Patient_Number,#FirstName,#LastName,#Gender,#Tribe,#Date_Of_Birth,#Visit_Number)";
string insert_stament2 = "Insert into Visit(Visit_Number)"
+ "Values(#Visit_Number)";
SqlCommand cmd = new SqlCommand(insert_statement, con);
SqlCommand cmd2 = new SqlCommand(insert_stament2, con2);
cmd2.Parameters.AddWithValue("#Visit_Number", txtVistNumber.Text);
cmd.Parameters.AddWithValue("#Patient_Number",txtpatientNum.Text);
cmd.Parameters.AddWithValue("#FirstName",txtfirstName.Text);
cmd.Parameters.AddWithValue("#LastName",txtlastname.Text);
cmd.Parameters.AddWithValue("#Gender", drl_gender.SelectedValue);
cmd.Parameters.AddWithValue("#Tribe",DropDownList1.Text);
cmd.Parameters.AddWithValue("#Date_Of_Birth", val_age.Text);
cmd.Parameters.AddWithValue("#Visit_Number", txtVistNumber.Text);
try
{
using (con)
{
con.Open();
int count = cmd.ExecuteNonQuery();
if (count > 0)
{
Response.Write("<script language=javascript>alert('Record Sucessfully Inserted!');</script>");
//Success_Message.Text = "Record inserted";
txtpatientNum.Text = String.Empty;
txtfirstName.Text = String.Empty;
txtlastname.Text = String.Empty;
txtVistNumber.Text = String.Empty;
DropDownList1.Text = String.Empty;
val_age.Text = String.Empty;
}
}
}
catch (SqlException ex)
{
{
VisitError_Message.Text = "Error Number:" + ex.Number.ToString() + " Error Message" + ex.Message + "On line Number" + ": " + ex.LineNumber;
}
}
catch (NullReferenceException nullexception)
{
VisitError_Message.Text = "Error Occurred, Error Type:" + nullexception.GetType().ToString() + "Error Message:" + nullexception.Message;
}
catch (DllNotFoundException dllexception)
{
VisitError_Message.Text = dllexception.GetType().ToString() + dllexception.Message;
}
finally
{
con.Close();
}
}
you not excuting you cmd2, you must execute the insert Visit_Number in cmd2 then excute your cmd, you can test this code
using (con2)
{
con2.Open();
cmd2.ExecuteNonQuery();
}
then you can excute your cmd
using (con)
{
con.Open();
int count = cmd.ExecuteNonQuery();
}
and you can do the work with the same connexion if you want
string connect = System.Configuration.ConfigurationManager.ConnectionStrings["db_connection"].ToString();
SqlConnection con = new SqlConnection(connect);
string visitnumber = txtVistNumber.Text.ToString();
string insert_statement = "Insert into Patient(Patient_Number,FirstName,LastName,Gender,Tribe,Date_Of_Birth,Visit_Number)"
+ "Values(#Patient_Number,#FirstName,#LastName,#Gender,#Tribe,#Date_Of_Birth,#Visit_Number)";
string insert_stament2 = "Insert into Visit(Visit_Number)"
+ "Values(#Visit_Number)";
using(con)
{
con.open;
SqlCommand cmd2 = new SqlCommand(insert_stament2, con);
cmd2.Parameters.AddWithValue("#Visit_Number", txtVistNumber.Text);
cmd2.ExecuteNonQuery();
SqlCommand cmd = new SqlCommand(insert_statement, con);
cmd.Parameters.AddWithValue("#Visit_Number", txtVistNumber.Text);
cmd.Parameters.AddWithValue("#Patient_Number",txtpatientNum.Text);
cmd.Parameters.AddWithValue("#FirstName",txtfirstName.Text);
cmd.Parameters.AddWithValue("#LastName",txtlastname.Text);
cmd.Parameters.AddWithValue("#Gender", drl_gender.SelectedValue);
cmd.Parameters.AddWithValue("#Tribe",DropDownList1.Text);
cmd.Parameters.AddWithValue("#Date_Of_Birth", val_age.Text);
cmd.Parameters.AddWithValue("#Visit_Number", txtVistNumber.Text);
cmd.ExecuteNonQuery();
}