Sql to java JDBC database [closed] - java

Closed. This question needs debugging details. It is not currently accepting answers.
Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
Closed 6 years ago.
Improve this question
I have a problem with searching a particular contact using part of a name. I know how it would look like in SQL but I cant implement it using Java.
if (rs.getString(nameTable LIKE '%name1%';)

Consider adding the LIKE clause to your SQL query instead of handling it in java code:
try(PreparedStatment ps = con.prepareStatement("SELECT * " +
" FROM Contact WHERE contactName like ?")) {
ps.setString(1, "%name1%");
try(ResultSet rs = ps.executeQuery()) {
while(rs.next()) {
//process your data
}
}
} catch(Exception e) {
//deal with it
}

Related

JDBC delete method seems to not be working in my Spring Boot service [closed]

Closed. This question needs debugging details. It is not currently accepting answers.
Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
Closed 1 year ago.
Improve this question
I'm trying to create a simple JDBC method to delete from my DB, and I'm not sure if I'm going about this the correct way. This is inside one of my services.
Method:
public void deleteLocation(Integer id) {
String DELETE = "DELETE FROM locale WHERE id=?";
namedParameterJdbcTemplate.update(DELETE, new BeanPropertySqlParameterSource(id));
}
I would try changing your update line to
namedParameterJdbcTemplate.update(DELETE, id);.
If you are using spring-boot. Then you should be using spring-data-jpa to manage your database. Jdbc is Hard way of doing this.
If you are using jdbc delete to a specific row use prepared statement. You can refer this:
preparedStatement = connection.prepareStatement("DELETE * from table_name WHERE id= ?");
preparedStatement.setInt(1, id);
return !preparedStatement.execute();

swing apps with jdbc connectivity and mysql [closed]

Closed. This question needs debugging details. It is not currently accepting answers.
Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
Closed 5 years ago.
Improve this question
stmt.executeUpdate("update fees set term_1 = "+hm.get("term_1").toString()+" term_2 ="+hm.get("term_1").toString()+"total = "+hm.get("total").toString()+"id = "+std_id);
Why it is not working when it is connected to JDBC?
Your update statement is invalid, you are missing comma(,)
Correct SQL Update statement should be
update fees set term_1 = 'something', term_2='something', total='something' where id = something;
So your final Java statement will be like:
stmt.executeUpdate( " Update fees set term_1 = '"+hm.get("term_1").toString()+"',"
+ " term_2 ='"+hm.get("term_1").toString()+"',"
+ " total = "+hm.get("total").toString()+"'"
+ " where id ="+std_id);
Note : Assuming all columns apart from id are of String type (i.e. term_1,term_2,total)

insert jdatechooser from java to database [closed]

Closed. This question needs debugging details. It is not currently accepting answers.
Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
Closed 7 years ago.
Improve this question
How can I insert jdatechooser from java to database? I have used all the solutions of the net but still I can't insert. Please help me.
I'm using eclipse environment.
This is my code:
try {
PreparedStatement stm= (PreparedStatement) con.prepareStatement("INSERT INTO d"+
"(dateEntré)"+
"VALUES(?)");
((PreparedStatement)stm).setDate(1,convertUtilDateToSqlDate(dateChooser.getDate()));
statement.execute();
JOptionPane.showMessageDialog(null,"added");
} catch (Exception e1) {
JOptionPane.showMessageDialog(null,e1.getMessage());
}
Your code example seems to be wrong, and this could just be a typo, but since you've provided no other information with regards to the error, this is all we have to go on...
You create a PreapredStatement called stmt, but then use statement to execute the query.
You should be using the same variable/instance to bind and excute the query. You should probably also use executeUpdate instead of execute, this provides some additional information when the statement is executed about the number of rows that were affected by the update.
try {
PreparedStatement stm= (PreparedStatement) con.prepareStatement("INSERT INTO d (dateEntré) VALUES(?)");
stm.setDate(1,convertUtilDateToSqlDate(dateChooser.getDate()));
int rows = statement.executeUpdate();
if (rows > 0) { // Should be 1
JOptionPane.showMessageDialog(null,"added");
} else {
JOptionPane.showMessageDialog(null,"Update failed for unknown reason");
}
} catch (Exception e1) {
JOptionPane.showMessageDialog(null,e1.getMessage());
e1.printStackTrace();
}
This of course assumes that the database column is a compatible type of java.sql.Date
Take a closer look at JDBC Database Access and Using Prepared Statements for more details.

Saving class instances into a database in Java [closed]

Closed. This question needs to be more focused. It is not currently accepting answers.
Want to improve this question? Update the question so it focuses on one problem only by editing this post.
Closed 8 years ago.
Improve this question
I want to learn how to execute basic SQL commands from a Java application. I have been searching for hours and all i can see are stuff to connect to a database. Can anyone provide a sample code to save instances of a simple class containing two fields, a Name(String) and Id(Int) in java.
The JDBC API is a Java API that can access any kind of tabular data, especially data stored in a Relational Database.
The following simple code fragment gives a simple example of these three steps:
public void connectToAndQueryDatabase(String username, String password) {
Connection con = DriverManager.getConnection(
"jdbc:myDriver:myDatabase",
username,
password);
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery("SELECT a, b, c FROM Table1");
while (rs.next()) {
int x = rs.getInt("a");
String s = rs.getString("b");
float f = rs.getFloat("c");
}
}

get maximum value from database and set into jtextfield [closed]

Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
Questions asking for code must demonstrate a minimal understanding of the problem being solved. Include attempted solutions, why they didn't work, and the expected results. See also: Stack Overflow question checklist
Closed 9 years ago.
Improve this question
I want to get maximum value from database (bill_number) and set into set into jtextfield. but I get error (void type not allowed here).
where is problem in my code
public void number(){
try{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection cn = DriverManager.getConnection("Jdbc:Odbc:ds_comboPractice");
String sql = "select count(Bill_Number)=? from combopractice";
PreparedStatement pst = cn.prepareStatement(sql);
pst.setString(1, txt4.setText(sql));
pst.executeQuery();
cn.close();
}
catch(ClassNotFoundException ex){
JOptionPane.showMessageDialog(this, "Class not found");
}
}
You need to do txt4.getText not setText
You then want to assign the results of your executeQuery to a ResultSet and read the result from that.
pst.setString(1, txt4.setText(sql));
setText() returns void
You need a String argument

Categories