How do you access the value of an SQL count () query in a Java program

I want to get to the value I am finding using the COUNT command of SQL. Normally I enter the column name I want to access into the getInt() getString() method, what do I do in this case when there is no specific column name.

I have used 'A开发者_Python百科S' in the same manner as is used to alias a table, I am not sure if this is going to work, I would think not.

Statement stmt3 = con.createStatement();
ResultSet rs3 = stmt3.executeQuery("SELECT COUNT(*) FROM "+lastTempTable+") AS count");
    while(rs3.next()){
    count = rs3.getInt("count");
    }

Use aliases:

SELECT COUNT(*) AS total FROM ..

and then

rs3.getInt("total")

The answers provided by Bohzo and Brabster will obviously work, but you could also just use:

rs3.getInt(1);

to get the value in the first, and in your case, only column.

I would expect this query to work with your program:

"SELECT COUNT(*) AS count FROM "+lastTempTable+")"

(You need to alias the column, not the table)

I have done it this way (example):

String query="SELECT count(t1.id) from t1, t2 where t1.id=t2.id and t2.email='"r@r.com"'";
int count=0;
try {
    ResultSet rs = DatabaseService.statementDataBase().executeQuery(query);
    while(rs.next())
        count=rs.getInt(1);
} catch (SQLException e) {
    e.printStackTrace();
} finally {
    //...
}

        <%
        try{
            Class.forName("com.mysql.cj.jdbc.Driver").newInstance();
            Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/bala","bala","bala");
            if(con == null) System.out.print("not connected");
            Statement st = con.createStatement();
            String myStatement = "select count(*) as total from locations";
            ResultSet rs = st.executeQuery(myStatement);
            int num = 0;
            while(rs.next()){
                num = (rs.getInt(1));
            }

        }
        catch(Exception e){
            System.out.println(e);  
        }

        %>

Statement stmt3 = con.createStatement();

ResultSet rs3 = stmt3.executeQuery("SELECT COUNT(*) AS count FROM "+lastTempTable+" ;");

count = rs3.getInt("count");

It's similar to above but you can try like

public Integer count(String tableName) throws CrateException {
        String query = String.format("Select count(*) as size from %s", tableName);
        try (Statement s = connection.createStatement()) {
            try (ResultSet resultSet = queryExecutor.executeQuery(s, query)) {
                Preconditions.checkArgument(resultSet.next(), "Result set is empty");
                return resultSet.getInt("size");
            }
        } catch (SQLException e) {
            throw new CrateException(e);
        }
    }
}