Is it possible to use prepared statements for dual in Oracle? - java

For example, if i have declared
String SQL = "select ? from dual";
Create a prepared statement for the above query
PreparedStatement preStmt = conn.prepareStatement(SQL);
And then try to add the expression as
preStmt.setString(1, expression);
How would that work? Is it possible to use it that way?

Related

Passing BIT in query as a parameter in Prepared Statement

I want to pass a bit as one of the parameters in Prepared Statement. My query should look like this :
query = select * from tbl_security_details('user',O::BIT)
I am framing the query as :
query = select * from tbl_security_details(?,?)
PreparedStatement ps = connection.prepareStatement(query);
ps.setString(1,"user")
ps.setString(2,"0::BIT")
However, this throws an error.
Can someone explain how I can pass 0::BIT from the prepare statement without it appending the single quote by itself and getting converted to String ?
Write the prepared statement so that the cast is part of the query:
String query = "select * from tbl_security_details(?, ?::bit)";
java.sql.PreparedStatement ps = connection.prepareStatement(query);
ps.setString(1, "user");
ps.setString(2, "0");
That is necessary, because you can only pass a constant value to the prepared statement, not an SQL expression.

SQLite functions using PreparedStatement

How to use SQLite function using PreparedStatement?
PreparedStatement stmt;
String query = "insert into Test values(?,?)";
stmt = conection.prepareStatement(query);
stmt.setString(2, "date('now')");
date('now') is the SQLite function I want to use, but it inserts "date('now')" as Text..
One way of achieving this is by changing your sql string, with this you may not need to set the date parameter anymore in your preparedstatement.
String query = "insert into Test values(?,date('now'))";
Now just you need to set the parameter 1
stmt.setString(1, <<param1 value>>);

Java PreparedStatement Comment on Table

I'm familiar with using java prepared statements to insert/update on a table. In oracle you can add a comment on a table, how would I use a preparedstatement to do that?
This was my initial attempt with no luck;
PreparedStatement stmt = con.prepareStatement("comment on table my_table is q'[?]'");
stmt.setString(1, description);
stmt.executeUpdate();
You can use system Oracle table and set comment there with PreparedStatement, like this:
PreparedStatement stmt = con.prepareStatement(
"UPDATE user_tab_comments SET comments = ? WHERE table_name = 'my_table'");
Or try to use simple statement:
String commentOnTableSQL = String.format("COMMENT ON TABLE my_table is '%s'", comment);
Statement statement = dbConnection.createStatement();
statement.execute(commentOnTableSQL);

Using PrepareStatement to get data with configurable table name

I'm trying to get some data from Oracle 11.2 using java and jdbc driver.
My goal is to get data from database using CallableStatement, but with no luck - I'm not able to put table name as parameter. I would like to have configurable table name in query. However, it would be good to keep it sanitized.
Here is an example..
public void getData() throws SQLException {
Connection conn = Config.getSQLConnection();
String query = "SELECT * FROM ?";
PreparedStatement st = conn.prepareStatement(query);
st.setString(1, Config.DATATABLE_NAME);
ResultSet rs = st.executeQuery();
if (rs.next()) {
System.out.println("SUCCESS");
System.out.println("ID:" + rs.getString("ID"));
} else {
System.out.println("FAILURE");
}
}
Is this the way it should work? Or am I missing something, or misused it?
A CallableStatement is used to make call to stored procedures.
From javadoc:
The interface used to execute SQL stored procedures
Use a PreparedStament instead for a normal select.
As an additional note don't pass the name of the table as parameter.
Create the query using concatenation.
Instead of
String query = "SELECT * FROM ?";
use
String query = "SELECT * FROM " + Config.DATATABLE_NAME;
You should use PreparedStatement instead of CallableStatement.
CallableStatement is an interface which is used to call stored procedures.

Oracle :SQL command not properly ended

String req="INSERT INTO NOTIFICATIONS VALUES(6,1,sysdate,'toz',02542,'bporp')(SELECT valide from mouvement where valide=?)";
I want to make a request with Conditions but I get the error:
SQL command not properly ended
You have an invalid SQL query. Here's your current SQL statement:
INSERT INTO NOTIFICATIONS VALUES(6,1,sysdate,'toz',02542,'bporp')(SELECT valide from mouvement where valide=?)
If we split this into several lines for better understanding, you will have this:
INSERT INTO NOTIFICATIONS
VALUES(6,1,sysdate,'toz',02542,'bporp')
(SELECT valide from mouvement where valide=?)
Which is not a valid statement, not even for any SQL tool. That's because you have 2 statements without separating them: an INSERT and then a SELECT, and you're not executing an INSERT INTO <TABLE1> SELECT ... FROM <TABLE2>.
You should execute a single SQL statement per Statement or PreparedStatement. This, in Java, should be done like this:
String sql1 = "INSERT INTO NOTIFICATIONS"
+ " VALUES(6,1,sysdate,'toz',02542,'bporp')";
String sql2 = "SELECT valide from mouvement where valide=?";
Statement stmt = con.createStatement();
stmt.executeUpdate(sql1);
PreparedStatement pstmt = con.prepareStatement(sql2);
pstmt.setString(1, <parameter_value>);
ResultSet rs = pstmt.executeQuery();

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