Hai, i gone thro u'r mysql documentation. but they haven't mentioned clearly. it's really big headache for users. using c language i want to connect to datadase and perform some queries(select,update,insert and delete).according to u'r documentation u said that first use mysql_int() and mysql_real_connect method to connect to the database in which library files these buildin functions are defined. this is my c file #include<stdio.h> #include<string.h> #include<stdlib.h> #include"/usr/local/mysql/include/mysql.h" #include"/usr/local/mysql/include/my_net.h" #include"/usr/local/mysql/include/mysqld_error.h" #include"/usr/local/mysql/include/mysys_err.h" main() { MYSQL mysql; mysql_init(&mysql); mysql_options(&mysql,MYSQL_OPT_COMPRESS,0); mysql_options(&mysql,MYSQL_READ_DEFAULT_GROUP,"odbc"); if (!mysql_real_connect(&mysql,"localhost","user=root","","InControl",0,NULL,0)) { printf(stderr,"Failed to connect to database: Error: %s\n",mysql_error(&mysql)); } } mysql_init() and mysql_real_connect() are build in functions. in which library files they defined this functions. pls mail me in detail Regards Lakshmi