原理

SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE 
WHERE TABLE_NAME = 表名 AND CONSTRAINT_NAME = 'PRIMARY'

方法

public static String getPk(String tableName) {String sql = "SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE WHERE TABLE_NAME = ? AND CONSTRAINT_NAME = 'PRIMARY'";PreparedStatement ps = null;ResultSet rs = null;String res = null;try {final Connection conn = JdbcUtil.getConnection();ps = conn.prepareStatement(sql);ps.setString(1, tableName);rs = ps.executeQuery();if (rs.next()) {res = rs.getString("COLUMN_NAME");}} catch (SQLException e) {e.printStackTrace();} finally {JdbcUtil.release(ps, rs);}return res;
}