Example usage for java.sql Statement executeQuery

List of usage examples for java.sql Statement executeQuery

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Introduction

In this page you can find the example usage for java.sql Statement executeQuery.

Prototype

ResultSet executeQuery(String sql) throws SQLException;

Source Link

Document

Executes the given SQL statement, which returns a single ResultSet object.

Usage

From source file:com.p6spy.engine.spy.P6TestUtil.java

public static int queryForInt(Connection con, String sql) throws SQLException {
    Statement stmt = null;
    ResultSet rs = null;//  ww w.  j  a va  2s  . c o  m
    try {
        stmt = con.createStatement();
        rs = stmt.executeQuery(sql);
        rs.next();
        return rs.getInt(1);
    } finally {
        if (rs != null)
            try {
                rs.close();
            } catch (Exception e) {
            }
        if (stmt != null)
            try {
                stmt.close();
            } catch (Exception e) {
            }
    }
}

From source file:com.data2semantics.yasgui.server.db.ConnectionFactory.java

/**
 * Check if database exists/*from  ww w.ja va 2  s.  co m*/
 * @param connect
 * @param dbName
 * @return
 * @throws SQLException
 */
private static boolean databaseExists(Connection connect, String dbName) throws SQLException {
    Statement statement = connect.createStatement();
    ResultSet resultSet = statement.executeQuery(
            "SELECT SCHEMA_NAME FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME = '" + dbName + "'");
    boolean exists = resultSet.next();
    statement.close();
    resultSet.close();
    return exists;
}

From source file:com.nabla.wapp.server.database.Database.java

/**
 * Test if a table has any data/* w  ww  .ja v a 2s.co m*/
 * @param conn      - database connection
 * @param tableName   - table name
 * @return success
 * @throws SQLException
 */
public static boolean isTableEmpty(final Connection conn, final String tableName) throws SQLException {
    final Statement stmt = conn.createStatement();
    try {
        final ResultSet rs = stmt.executeQuery("SELECT COUNT(*) FROM " + tableName + ";");
        try {
            return rs.next() && rs.getInt(1) == 0;
        } finally {
            rs.close();
        }
    } finally {
        stmt.close();
    }
}

From source file:net.big_oh.common.jdbc.JdbcProxyExerciser.java

private static void exerciseRegularSelect(Connection con) throws SQLException {
    logger.info(StringUtils.center("exercise regular select", 100, "-"));

    Statement stmt = null;
    ResultSet rs = null;/*from w  w w  . ja v  a  2 s.c  o  m*/
    try {
        stmt = con.createStatement();
        rs = stmt.executeQuery("SELECT * FROM TEST_TABLE");
        while (rs.next()) {
            System.out.println(rs.getString("TEST_COLUMN"));
        }
    } finally {
        DbUtils.closeQuietly(rs);
        DbUtils.closeQuietly(stmt);
    }

}

From source file:CheckJDBCInstallation_Oracle.java

/**
 * Test Validity of a Connection/*  w w  w  .j av  a  2  s  .c  o m*/
 * 
 * @param conn
 *          a JDBC connection object
 * @param query
 *          a sql query to test against database connection
 * @return true if a given connection object is a valid one; otherwise return
 *         false.
 */
public static boolean testConnection(Connection conn, String query) {

    ResultSet rs = null;
    Statement stmt = null;
    try {
        stmt = conn.createStatement();
        if (stmt == null) {
            return false;
        }

        rs = stmt.executeQuery(query);
        if (rs == null) {
            return false;
        }

        if (rs.next()) {
            // connection object is valid: we were able to
            // connect to the database and return something useful.
            return true;
        }
        // there is no hope any more for the validity
        // of the connection object
        return false;

    } catch (Exception e) {
        return false;
    } finally {
        // close database resources
        try {
            rs.close();
            stmt.close();
        } catch (Exception e) {
            // ignore
        }
    }
}

From source file:CheckJDBCInstallation.java

/**
 * Test Validity of a Connection/*w ww .  j  a v  a 2s.  c  o m*/
 * 
 * @param conn
 *          a JDBC connection object
 * @param query
 *          a sql query to test against db connection
 * @return true if a given connection object is a valid one; otherwise return
 *         false.
 */
public static boolean testConnection(Connection conn, String query) {
    ResultSet rs = null;
    Statement stmt = null;
    try {
        stmt = conn.createStatement();
        if (stmt == null) {
            return false;
        }

        rs = stmt.executeQuery(query);
        if (rs == null) {
            return false;
        }

        // connection object is valid: you were able to
        // connect to the database and return something useful.
        if (rs.next()) {
            return true;
        }

        // there is no hope any more for the validity
        // of the Connection object
        return false;
    } catch (Exception e) {
        // something went wrong: connection is bad
        return false;
    } finally {
        // close database resources
        try {
            rs.close();
            stmt.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

From source file:CheckJDBCInstallation_MySQL.java

/**
 * Test Validity of a Connection/*from   ww  w .  ja v a  2 s  . c o m*/
 * 
 * @param conn
 *          a JDBC connection object
 * @param query
 *          a sql query to test against database connection
 * @return true if a given connection object is a valid one; otherwise return
 *         false.
 */
public static boolean testConnection(Connection conn, String query) {

    ResultSet rs = null;
    Statement stmt = null;
    try {
        stmt = conn.createStatement();
        if (stmt == null) {
            return false;
        }

        rs = stmt.executeQuery(query);
        if (rs == null) {
            return false;
        }

        if (rs.next()) {
            // connection object is valid: we were able to
            // connect to the database and return something useful.
            return true;
        }

        // there is no hope any more for the validity
        // of the connection object
        return false;

    } catch (Exception e) {
        //
        // something went wrong: connection is bad
        //
        return false;
    } finally {
        try {
            rs.close();
            stmt.close();
            conn.close();
        } catch (Exception e) {
        }
    }
}

From source file:net.tirasa.ilgrosso.resetdb.Main.java

private static void resetPostgreSQL(final Connection conn) throws Exception {

    final Statement statement = conn.createStatement();

    final ResultSet resultSet = statement
            .executeQuery("SELECT 'DROP TABLE ' || c.relname || ' CASCADE;' FROM pg_catalog.pg_class c "
                    + "LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace "
                    + "WHERE c.relkind IN ('r','') AND n.nspname NOT IN ('pg_catalog', 'pg_toast') "
                    + "AND pg_catalog.pg_table_is_visible(c.oid)");
    final List<String> drops = new ArrayList<String>();
    while (resultSet.next()) {
        drops.add(resultSet.getString(1));
    }//from   w w  w.  j a v a2  s  .  c om
    resultSet.close();

    for (String drop : drops) {
        statement.executeUpdate(drop.substring(0, drop.length() - 1));
    }

    statement.close();
    conn.close();
}

From source file:net.tirasa.ilgrosso.resetdb.Main.java

private static void resetSQLServer(final Connection conn) throws SQLException {

    Statement statement = conn.createStatement();
    final ResultSet resultSet = statement.executeQuery("SELECT sysobjects.name " + "FROM sysobjects "
            + "JOIN sysusers " + "ON sysobjects.uid = sysusers.uid "
            + "WHERE OBJECTPROPERTY(sysobjects.id, N'IsView') = 1");
    final List<String> drops = new ArrayList<String>();
    while (resultSet.next()) {
        drops.add("DROP VIEW " + resultSet.getString(1));
    }//from   w  w  w .  j  a va2s. c  o  m
    resultSet.close();
    statement.close();

    statement = conn.createStatement();
    for (String drop : drops) {
        statement.executeUpdate(drop);
    }
    statement.close();

    statement = conn.createStatement();
    statement.executeUpdate("EXEC sp_MSforeachtable \"ALTER TABLE ? NOCHECK CONSTRAINT all\"");
    statement.close();

    statement = conn.createStatement();
    statement.executeUpdate("EXEC sp_MSforeachtable \"DROP TABLE ?\"");
    statement.close();

    conn.close();
}

From source file:net.tirasa.ilgrosso.resetdb.Main.java

private static void resetMySQL(final Connection conn) throws Exception {

    final Statement statement = conn.createStatement();

    ResultSet resultSet = statement
            .executeQuery("SELECT concat('DROP VIEW IF EXISTS ', table_name, ' CASCADE;')"
                    + "FROM information_schema.views;");
    final List<String> drops = new ArrayList<String>();
    while (resultSet.next()) {
        drops.add(resultSet.getString(1));
    }//from  www .j a v a  2 s.co m
    resultSet.close();

    for (String drop : drops) {
        statement.executeUpdate(drop.substring(0, drop.length() - 1));
    }
    drops.clear();

    drops.add("SET FOREIGN_KEY_CHECKS = 0;");
    resultSet = statement.executeQuery("SELECT concat('DROP TABLE IF EXISTS ', table_name, ' CASCADE;')"
            + "FROM information_schema.tables;");
    while (resultSet.next()) {
        drops.add(resultSet.getString(1));
    }
    resultSet.close();
    drops.add("SET FOREIGN_KEY_CHECKS = 1;");

    for (String drop : drops) {
        statement.executeUpdate(drop.substring(0, drop.length() - 1));
    }

    statement.close();
    conn.close();
}