Summer Blog

十万个为什么

本文记录一些突然很想知道的问题，可能是某个功能的实现细节，可能是某个框架的运行原理，也可能是某个事件的来龙去脉等等。反正，应该会是一些奇奇怪怪的东西吧～

框架

MyBaits 插入后如何得到生成的主键 id 的

MyBaits 中的SqlRunner封装了PreparedStatement，在insert方法中，调用了Statement.getGeneratedKeys()，然后循环将生成的主键返回。

    /**
     * Retrieves any auto-generated keys created as a result of executing this
     * <code>Statement</code> object. If this <code>Statement</code> object did
     * not generate any keys, an empty <code>ResultSet</code>
     * object is returned.
     *
     *<p><B>Note:</B>If the columns which represent the auto-generated keys were not specified,
     * the JDBC driver implementation will determine the columns which best represent the auto-generated keys.
     *
     * @return a <code>ResultSet</code> object containing the auto-generated key(s)
     *         generated by the execution of this <code>Statement</code> object
     * @exception SQLException if a database access error occurs or
     * this method is called on a closed <code>Statement</code>
     * @throws SQLFeatureNotSupportedException  if the JDBC driver does not support this method
     * @since 1.4
     */
    ResultSet getGeneratedKeys() throws SQLException;

英语

什么时候con读/kən/，什么时候读/kɔn/

有些发“ɔ”的音，有些发“ə”的音。重音在单词的开头，就要发的“ɔ”音，例如concentrate，重音在c上；complement,重音也在c 上。重音在单词的后面，就是“ə”音，例如computer，重音在p上；constrict，重音在s上。

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