Showing posts with label MySQL. Show all posts
Showing posts with label MySQL. Show all posts

Sunday, November 11, 2007

Problems to be thinking

1. why mysql comes out a problem with "release mode", say not start with "/"

2. why when there is directory, there may be problem with compling

Saturday, November 10, 2007

Some notes on MySQL

1. how to check whether a field is NULL?
First, NULL in MySQL is not a value, it is a condition. So if you try and write something "= NULL" you'll get an empty set rather than the results you're looking for. Try "IS NULL" instead. For example, mysql> select * from demo_people left join demo_property on demo_people.pid = demo_property.pid where spid is NULL;

2. becaulful with this code:
while((row=mysql_fetch_row(res)))
{
for(int j=0;j {
printf("%s ",row[j]);
}
printf("\n");
}
if the MySQL query get a tuple whchi has field "NULL", then problem comes!

MySQL vs C/C++

1. it seems row[0] (MYSQL_ROW row) is a char*, great

Thursday, November 8, 2007

Fulltext Search in MySQL

There are some points I encountered during my experiements:
1. how to change ft_min_word_len for windows platform: add one line ft_min_word_len = 2 in my.ini file in MySQL installment directory

2. After we changed the ft_min_word_len variable, we have to rebuild the fulltext index by ALTER TABLE person ADD FULLTEXT(name)