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insert data into mysql database - java eclipse

i have this code to insert data into mysql db, when i run on eclipse the following code it doesn't show any errors but no data are inserted into the db.
this is my code.
public static void main (String[] args) {
try {
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/database_spie";
Connection conn = DriverManager.getConnection(url,"root","lecci");
Statement st = conn.createStatement();
st = conn.prepareStatement("INSERT INTO database_spie.notifiche(titolo, destinatario, testo) \r\n" +
"VALUES ('inizio', 'tutti', 'spie per una notte inizia tra 30 minuti');");
conn.close();
System.out.println("closed");
} catch (Exception e) {
System.err.println("Got an exception! ");
System.err.println(e.getMessage());
}
}

First point is you need to use PreparedStatement not Statement.
You have only created connection, created query and then closed connection
PreparedStatement st = conn.prepareStatement("INSERT INTO database_spie.notifiche(titolo, destinatario, testo) \r\n" +
"VALUES ('inizio', 'tutti', 'spie per una notte inizia tra 30 minuti');");
//Before closing connection you need to execute it using following line of code
st.executeUpdate();
conn.close();
You should follow these steps: source (https://alvinalexander.com/java/java-mysql-update-query-example)
Create a Java Connection to our MySQL database.
Create a SQL UPDATE statement, using the Java PreparedStatement syntax.
Set the fields on
our Java PreparedStatement object
Execute a Java PreparedStatement
Close our Java database connection. Catch any exceptions that may
come up during the process
If you are using Statement then you need to do it like below
Statement stmt=con.createStatement();
//pass the query string to it
stmt.executeUpdate("INSERT INTO database_spie.notifiche(titolo, destinatario, testo) \r\n" +
"VALUES ('inizio', 'tutti', 'spie per una notte inizia tra 30 minuti');");

You have not executed the statement, just created it then closed the connection.
there is an execute() method on the PreparedStatement object.

How to assign a Value taken from the database to a label?

I need to assign a string taken by a query from the database to a Jlabel. I tried many methods but failed. How can i do it?
try{
String sql="SELECT MAX(allocationID) FROM allocation where unit='"+ dept + " ' ";
pst=conn.prepareStatement(sql);
String x= (pst.execute());
}
catch(Exception e){
}

Need to study the steps to connect to the database in java First db steps
Get the resultset from the statment by calling ResultSet rs = pst.execute();
Iterate through the list of rows by using the resultset object.
After that assign the value to the JLabel.

You just made several errors in your tiny program, take a look at the code below as an example:
// your way of using prepared statement is wrong.
// use like this
String sql="SELECT MAX(allocationID) FROM allocation where unit=?;";
Connection conn = getConnection();
PreparedStatement ps = conn.prepareStatement(sql);
// assign values to the variables in the query string
ps.setString(1, dept);
// execute the query
ResultSet rst = ps.executeQuery();
// parse the result set to get the value
// You'd better do some check here to ensure you get the right result
rst.next();
String x = rst.getInt(1) + "";
ps.close();
conn.close();
}
Have a look at the article if you are interested:https://docs.oracle.com/javase/tutorial/jdbc/basics/retrieving.html

Getting resultset from insert statement

i have the below code, where I'm inserting records to a table. When I try to get resultset, it returns null. How to get the latest added row into a resultset?
String sql1 = "INSERT INTO [xxxx].[dbo].[xxxxxx](WORKFLOW_SEQ_NBR," +
" WORKFLOW_LOG_TYPE_CODE, WORKFLOW_STATUS_CODE, DISP_CODE, DISP_USER, DISP_COMMENT, DISP_TITLE, DISP_TS)" +
"VALUES(?,?,?,?,?,?,?,?)";
PreparedStatement pst = connect.prepareStatement(sql1);
pst.setString(1, ...);
pst.setString(2, ...);
...
...
...
pst.executeUpdate();
ResultSet rstest = pst.executeQuery();
// ResultSet rstest = pst.getResultSet();
EDIT: Resolved
added following method to go to the last added row
st.execute("Select * from [xxxx].[dbo].[xxxxxxxxx]");
ResultSet rstest = st.getResultSet();
rstest.afterLast();
GETLASTINSERTED:
while(rstest.previous()){
System.out.println(rstest.getObject(1));
break GETLASTINSERTED;//to read only the last row
}

When using a SQL statement such as INSERT, UPDATE or DELETE with a PreparedStatement, you must use executeUpdate, which will return the number of affeted rows. In this case there is simply no ResultSet produced by the sql operation and thus calling executeQuery will throw a SQLException.
If you actually need a ResultSet you must make another statement with a SELECT SQL operation.
See the javadoc for PreparedStatement#executeQuery and PreparedStatement#executeUpdate

Seems like this is an older question, but i'm looking for a similar solution, so maybe people will still need this.
If you're doing an insert statement, you can use the :
Connection.PreparedStatement(String, String[]) constructor, and assign those to a ResultSet with ps.getGeneratedKeys().
It would look something like this:
public void sqlQuery() {
PreparedStatement ps = null;
ResultSet rs = null;
Connection conn; //Assume this is a properly defined Connection
String sql = "insert whatever into whatever";
ps = conn.prepareStatement(sql, new String[]{"example"});
//do anything else you need to do with the preparedStatement
ps.execute;
rs = ps.getGeneratedKeys();
while(rs.next()){
//do whatever is needed with the ResultSet
}
ps.close();
rs.close();
}

Connection#prepareStatement() - Creates a PreparedStatement object for sending parameterized SQL statements to the database.
which means connect.prepareStatement(sql1); created the PreparedStatement object using your insert query.
and when you did pst.executeUpdate(); it will return the row count for SQL Data Manipulation Language (DML) statements or 0 for SQL statements that return nothing
Now if you again want to fetch the data inserted you need to create a new PreparedStatement object with Select query.
PreparedStatement pstmt = connect.prepareStatement("SELECT * FROM tableName");
then this shall give you the ResultSet object that contains the data produced by the query
ResultSet rstest = pstmt.executeQuery();

Execute multiple SQL statements in java

I want to execute a query in Java.
I create a connection. Then I want to execute an INSERT statement, when done, the connection is closed but I want to execute some insert statement by a connection and when the loop is finished then closing connection.
What can I do ?
My sample code is :
public NewClass() throws SQLException {
try {
Class.forName("oracle.jdbc.driver.OracleDriver");
} catch (ClassNotFoundException e) {
System.out.println("Where is your Oracle JDBC Driver?");
return;
}
System.out.println("Oracle JDBC Driver Registered!");
Connection connection = null;
try {
connection = DriverManager.getConnection(
"jdbc:oracle:thin:#localhost:1521:orcl1", "test",
"oracle");
} catch (SQLException e) {
System.out.println("Connection Failed! Check output console");
return;
}
if (connection != null) {
Statement stmt = connection.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * from test.special_columns");
while (rs.next()) {
this.ColName = rs.getNString("column_name");
this.script = "insert into test.alldata (colname) ( select " + ColName + " from test.alldata2 ) " ;
stmt.executeUpdate("" + script);
}
}
else {
System.out.println("Failed to make connection!");
}
}
When the select statement ("SELECT * from test.special_columns") is executed, the loop must be twice, but when (stmt.executeUpdate("" + script)) is executed and done, then closing the connection and return from the class.

Following example uses addBatch & executeBatch commands to execute multiple SQL commands simultaneously.
import java.sql.*;
public class jdbcConn {
public static void main(String[] args) throws Exception{
Class.forName("org.apache.derby.jdbc.ClientDriver");
Connection con = DriverManager.getConnection
("jdbc:derby://localhost:1527/testDb","name","pass");
Statement stmt = con.createStatement
(ResultSet.TYPE_SCROLL_SENSITIVE,
ResultSet.CONCUR_UPDATABLE);
String insertEmp1 = "insert into emp values
(10,'jay','trainee')";
String insertEmp2 = "insert into emp values
(11,'jayes','trainee')";
String insertEmp3 = "insert into emp values
(12,'shail','trainee')";
con.setAutoCommit(false);
stmt.addBatch(insertEmp1);
stmt.addBatch(insertEmp2);
stmt.addBatch(insertEmp3);
ResultSet rs = stmt.executeQuery("select * from emp");
rs.last();
System.out.println("rows before batch execution= "
+ rs.getRow());
stmt.executeBatch();
con.commit();
System.out.println("Batch executed");
rs = stmt.executeQuery("select * from emp");
rs.last();
System.out.println("rows after batch execution= "
+ rs.getRow());
}
}
Result:
The above code sample will produce the following result.The result may vary.
rows before batch execution= 6
Batch executed
rows after batch execution= = 9
Source: Execute multiple SQL statements

In the abscence of the schema or the data contained in each table I'm going to make the following assumptions:
The table special_columns could look like this:
column_name
-----------
column_1
column_2
column_3
The table alldata2 could look like this:
column_1 | column_2 | column_3
---------------------------------
value_1_1 | value_2_1 | value_3_1
value_1_2 | value_2_2 | value_3_2
The table alldata should, after inserts have, happened look like this:
colname
---------
value_1_1
value_1_2
value_2_1
value_2_2
value_3_1
value_3_2
Given these assumptions you can copy the data like this:
try (
Connection connection = DriverManager.getConnection("jdbc:oracle:thin:#localhost:1521:orcl1", "test", "oracle")
)
{
StringBuilder columnNames = new StringBuilder();
try (
Statement select = connection.createStatement();
ResultSet specialColumns = select.executeQuery("SELECT column_name FROM special_columns");
Statement insert = connection.createStatement()
)
{
while (specialColumns.next())
{
int batchSize = 0;
insert.addBatch("INSERT INTO alldata(colname) SELECT " + specialColumns.getString(1) + " FROM alldata2");
if (batchSize >= MAX_BATCH_SIZE)
{
insert.executeBatch();
batchSize = 0;
}
}
insert.executeBatch();
}
A couple of things to note:
MAX_BATCH_SIZE should be set to a value based on your database configuration and the data being inserted.
this code is using the Java 7 try-with-resources feature to ensure the database resources are released when they're finished with.
you haven't needed to do a Class.forName since the service provider mechanism was introduced as detailed in the JavaDoc for DriverManager.

There are two problems in your code. First you use the same Statement object (stmt) to execute the select query, and the insert. In JDBC, executing a statement will close the ResultSet of the previous execute on the same object.
In your code, you loop over the ResultSet and execute an insert for each row. However executing that statement will close the ResultSet and therefor on the next iteration the call to next() will throw an SQLException as the ResultSet is closed.
The solution is to use two Statement objects: one for the select and one for the insert. This will however not always work by default, as you are working in autoCommit (this is the default), and with auto commit, the execution of any statement will commit any previous transactions (which usually also closes the ResultSet, although this may differ between databases and JDBC drivers). You either need to disable auto commit, or create the result set as holdable over commit (unless that already is the default of your JDBC driver).

quotation marks in string parameter insert statement

Hi I've been trying to insert a string into a sqlite database through java. but the string parameter I'm passing in the values sql statement has quotation marks in it as content. I'm thinking that is the error I'm getting why it isn't inserting into the database. is there a way to bypass the quotation marks in the insert statement. thank you.
this is the code:
public void addNote(String topicadd, String contentadd) throws Exception
{
try
{
getConnection();
statement = conn.createStatement();
statement.executeUpdate("insert into tbl_notes (notes_topic, notes_content) values ('" + topicadd + "', '" + contentadd +"')");
System.out.println("inserted note");
}
catch (Exception m)
{`enter code here`
System.out.println("error insert topic");
System.out.println(m.getMessage());
}
}
this is the parameter kind of long... this is all in contentadd
import java.sql.*;
Resultset rset = null; (this has no new ResultSet() initialization)
Connection conn = null; (this has no new initialization too...)
Statement statement = null; (this has now new initialization)
always.....
try
{
}
catch (Exception e) <- can switch e for any other alphabet
{
e.getMessage();
System.out.println("error this module"); <- personal practice
throw e;
}
- getting connection
Class.forName("org.sqlite.JDBC");
conn = DriverManager.getConnection("jdbc:sqlite:m.db");
*** this is sqlite connection format 'm.db' is the database name
establish connection first..
statement syntax follows:
statement = conn.createStatement();
rset = statement.executeQuery("select * from tbl_notes");
- executeQuery is used for SELECT sql statements
rset = statement.executeUpdate("insert into tbl_notes (ID, status) values
('100', 'status here');
the whole text is in string contentadd, I'm making a short note-taking program... Well, it doesn't execute the insert statement... error somewhere near (word from text) on command prompt... I'm using sqlite... Please let me know if you need more detail. thank you again.

Use a PreparedStatement to insert values containing special characters:
getConnection();
PreparedStatement statement = conn.prepareStatement("insert into tbl_notes (notes_topic, notes_content) values (?, ?)");
statement.setString(1, topicadd);
statement.setString(2, contentadd);
statement.executeUpdate();
As you see you can use parameters with a PreparedStatement which can contain also quotation marks.
Also you get some protection against SQL injection because the Strings given to a PreparedStatement are escaped accordingly.