Querying a database via a constructor

Querying a database via a constructor

I'm trying create a database query class that I can re-use to search or
display items from the database.
I'd like to be able to pass the query specifications via a constructor.
However, I'm gettin this error:
run:
Connecting to a selected database...
Connected database successfully...
Creating statement...
org.h2.jdbc.JdbcSQLException: Data conversion error converting ; SQL
statement:
This is my code so far:
import java.sql.*;
public class RsToAList {
private final String table;
private final String columns;
private final String whereColumn;
private final String equalsEntry;
public RsToAList (String columns, String table, String whereColumn,
String equalsEntry) {
this.table = table;
this.columns = columns;
this.whereColumn = whereColumn;
this.equalsEntry = equalsEntry;
}
// JDBC driver name and database URL
static String JDBC_DRIVER = "org.h2.Driver";
static String DB_URL = "jdbc:h2:file:C:/tryDb/tryDb";
// Database credentials
static String USER = "sa";
static String PASS = "";
public static void main (String[] args) {
RsToAList tryAndGet = new RsToAList("fullNames", "CLIENT",
"postOfficeBoxNumber", "6448");
tryAndGet.ourQuerryMethod();
}
public void ourQuerryMethod () {
Connection conn = null;
Statement stmt = null;
try {
// STEP 2: Register JDBC driver
Class.forName(getJDBC_DRIVER());
// STEP 3: Open a connection
System.out.println("Connecting to a selected database...");
conn = DriverManager.getConnection(getDB_URL(), getUSER(),
getPASS());
System.out.println("Connected database successfully...");
// STEP 4: Execute a query
System.out.println("Creating statement...");
stmt = conn.createStatement();
String sql = "SELECT " + (columns) + " FROM " + (table) + "
WHERE "+ (whereColumn) +" = "+ (equalsEntry) +"";
ResultSet rs = stmt.executeQuery(sql);
//STEP 5: Extract data from result set
while (rs.next()) {
// Retrieve by column name
String first = rs.getString(columns);
// Display values
System.out.print("ID: " + first);
}
rs.close();
} catch (SQLException se) {
// Handle errors for JDBC
se.printStackTrace();
} catch (Exception e) {
// Handle errors for Class.forName
e.printStackTrace();
} finally {
// finally block used to close resources
try {
if (stmt != null)
conn.close();
} catch (SQLException se) {
} // do nothing
try {
if (conn != null)
conn.close();
} catch (SQLException se) {
se.printStackTrace();
} // end finally try
} // end try
System.out.println("Goodbye!");
} // end main
/**
* @return the JDBC_DRIVER
*/
public static String getJDBC_DRIVER() {
return JDBC_DRIVER;
}
/**
* @param aJDBC_DRIVER the JDBC_DRIVER to set
*/
public static void setJDBC_DRIVER(String aJDBC_DRIVER) {
JDBC_DRIVER = aJDBC_DRIVER;
}
/**
* @return the DB_URL
*/
public static String getDB_URL() {
return DB_URL;
}
/**
* @param aDB_URL the DB_URL to set
*/
public static void setDB_URL(String aDB_URL) {
DB_URL = aDB_URL;
}
/**
* @return the USER
*/
public static String getUSER() {
return USER;
}
/**
* @param aUSER the USER to set
*/
public static void setUSER(String aUSER) {
USER = aUSER;
}
/**
* @return the PASS
*/
public static String getPASS() {
return PASS;
}
/**
* @param aPASS the PASS to set
*/
public static void setPASS(String aPASS) {
PASS = aPASS;
}
}