SQLITE源码剖析(12)

gmdzxx

　　声明：本SQLite源码剖析系列为刘兴(http://deepfuture.iyunv.com/)原创，未经笔者授权，任何人和机构不能转载
　　/*
　　** The type for a callback function.
　　** This is legacy and deprecated.  It is included for historical
　　** compatibility and is not documented.
　　*/回调函数，不赞成这种旧版本遗留下来的机制，它被包含进来，为了历史兼
　　**容性,没有相关证实
　　typedef int (*sqlite3_callback)(void*,int,char**, char**);
　　/*
　　** CAPI3REF: One-Step Query Execution Interface
　　**查询执行接口
　　** The sqlite3_exec() interface is a convenience wrapper around
　　** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
　　** that allows an application to run multiple statements of SQL
　　** without having to use a lot of C code. 
　　**sqlite3_exec()接口包装了[sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()]，方便使用，允许应用程序执行多语句的SQL，无使用大量C代码
　　**sqlite3_exec()符合UTF8编码要求 ，用分号分隔的SQL语句为它的第二个
　　**参数，database connection数据 库连接为第一个参数，做为第三个参数的回调函数如果非空，则SQL执行结果的每一行都会调用该函数
　　** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
　　** semicolon-separate SQL statements passed into its 2nd argument,
　　** in the context of the [database connection] passed in as its 1st
　　** argument.  ^If the callback function of the 3rd argument to
　　** sqlite3_exec() is not NULL, then it is invoked for each result row
　　** coming out of the evaluated SQL statements.