小编use*_*537的帖子

我正在尝试为mysql编写一个自定义的用户定义函数,所以我以http://www.mysqludf.org/index.php中的str_ucwords函数为例来构建我自己的函数.

my_bool str_ucwords_init(UDF_INIT *initid, UDF_ARGS *args, char *message)
{
    /* make sure user has provided exactly one string argument */
    if (args->arg_count != 1 || args->arg_type[0] != STRING_RESULT || args->args[0] == NULL)
    {
        strcpy(message,"str_ucwords requires one string argument");
        return 1;
    }

    /* str_ucwords() will not be returning null */
    initid->maybe_null=0;

    return 0;
}

char *str_ucwords(UDF_INIT *initid, UDF_ARGS *args,
    char *result, unsigned long *res_length, 
    char *null_value, char *error)
{
    int i;
    int new_word = 0;

    // copy the argument …