(18) Database programming--c language Operations database

Source: Internet
Author: User
Tags sprintf



#include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <string.h> #include < errno.h> #include <termios.h> #include <mysql/mysql.h> #define BUFSIZE 1024MYSQL MySQL, *connection;void Deletename (char *sql) {memset (SQL, 0, BUFSIZE), sprintf (SQL, "%s", "Enter the name to be killed;:"); write (Stdout_fileno, SQL, strlen ( SQL)); This is an alternative to the printf function, so that writing does not require \ nthe output of char name[1024];memset (name, 0, sizeof) to the screen, read (Stdin_fileno, name, sizeof ( name)); Wait for the user to enter the name to delete, assuming that the user entered the "Rice Island Love" Name[strlen (name)-1] = 0; Replace the last bit of the string with 0, and the last place is the integer 0 instead of the character ' 0 ' memset (SQL, 0, BUFSIZE); sprintf (SQL, "DELETE from table1 WHERE name = '%s '", name); sql = DELETE from table1 WHERE name = ' Rice Island Love ' printf (' '%s ' \ n ', SQL);} void Insertname (char *sql) {memset (SQL, 0, BUFSIZE), sprintf (SQL, "%s", "Enter the name to insert;:"); write (Stdout_fileno, SQL, BUFSIZE); This is an alternative to the printf function, so that writing does not require \ nthe output of char name[1024];memset (name, 0, sizeof) to the screen, read (Stdin_fileno, name, sizeof ( name)); Wait for the user to enter the name to insert, assuming that the user entered "Rice Island Love" name[strLen (name)-1] = 0; Replace the last bit of the string with 0, and the last place is the integer 0 instead of the character ' 0 ' memset (SQL, 0, BUFSIZE), sprintf (SQL, "%s", "Enter the gender to insert;:"); Write (Stdout_fileno , SQL, strlen (SQL)), char sex[1024];memset (sex, 0, sizeof (sex)); Read (Stdin_fileno, sex, sizeof (sex)); Wait for the user to enter the gender to be inserted, Sex[strlen (Sex)-1] = 0; Replace the last bit of the string with 0, and the last place is the integer 0 instead of the character ' 0 ' memset (SQL, 0, BUFSIZE), sprintf (SQL, "%s", "Enter the age to insert;:"); Write (Stdout_fileno , SQL, strlen (SQL)), Char Age[1024];memset (age, 0, sizeof); Read (Stdin_fileno, age, sizeof); Waits for the user to enter the age to insert Age[strlen-1] = 0; Replace the last bit of the string with 0, and the last place is the integer 0 instead of the character ' 0 ' memset (SQL, 0, BUFSIZE), sprintf (SQL, "%s", "enter class to insert;:"); Write (Stdout_fileno , SQL, strlen (SQL)), char classes[1024];memset (classes, 0, sizeof (classes)); Read (Stdin_fileno, classes, sizeof (classes )); Wait for the user to enter the class to be inserted Classes[strlen (classes)-1] = 0; Replace the last bit of the string with 0, and the last place is the integer 0 instead of the character ' 0 ' memset (SQL, 0, BUFSIZE); sprintf (SQL, "INSERT into table1 (name, sex, age, Class) VALUES ('%s ', '%s ',%s, '%s ') ", Name, sex, age, classes); SQL = DELete from table1 WHERE name = ' Rice Island Love ' printf (' '%s ' \ n ', SQL);} void UpdateName (char *sql) {memset (SQL, 0, BUFSIZE), sprintf (SQL, "%s", "Please enter name to be modified;:"); write (Stdout_fileno, SQL, Strlen (SQL)); This is an alternative to the printf function, so that writing does not require \ nthe output of char name[1024];memset (name, 0, sizeof) to the screen, read (Stdin_fileno, name, sizeof ( name)); Wait for the user to enter the name to insert, assuming that the user entered "Rice Island Love" Name[strlen (name)-1] = 0; Replace the last bit of the string with 0, and the last place is the integer 0 instead of the character ' 0 ' memset (SQL, 0, BUFSIZE), sprintf (SQL, "%s", "Enter gender for sex;:"); Write (Stdout_fileno , SQL, strlen (SQL)), char sex[1024];memset (sex, 0, sizeof (sex)); Read (Stdin_fileno, sex, sizeof (sex)); Wait for the user to enter the gender to be inserted, Sex[strlen (Sex)-1] = 0; Replace the last bit of the string with 0, and the last place is the integer 0 instead of the character ' 0 ' memset (SQL, 0, BUFSIZE), sprintf (SQL, "%s", "enter age to age;:"); Write (Stdout_fileno , SQL, strlen (SQL)), Char Age[1024];memset (age, 0, sizeof); Read (Stdin_fileno, age, sizeof); Waits for the user to enter the age to insert Age[strlen-1] = 0; Replace the last bit of the string with 0, and the last place is the integer 0 instead of the character ' 0 ' memset (SQL, 0, BUFSIZE), sprintf (SQL, "%s", "Enter the class to be modified;:"); Write (Stdout_fileno , SQL, StRlen (SQL)); Char classes[1024];memset (classes, 0, sizeof (classes)); Read (Stdin_fileno, classes, sizeof (classes)); Wait for the user to enter the class to be inserted Classes[strlen (classes)-1] = 0; Replace the last bit of the string with 0, and the last place is the integer 0 instead of the character ' 0 ' memset (SQL, 0, BUFSIZE); sprintf (sql, "UPDATE table1 SET sex = '%s ', age =%s, class = '%s ' WHERE name = '%s ' ", sex, age, classes, name); sql = DELETE from table1 WHERE name = ' Rice Island Love ' printf (' '%s ' \ n ', SQL);} void Selectname (const char *sql) {/*char sql[1024];memset (SQL, 0, BUFSIZE), sprintf (SQL, "%s", "Please enter the name to be queried;:"); Write ( Stdout_fileno, SQL, strlen (SQL)); This is an alternative to the printf function, so that writing does not require \ nthe output of char name[1024];memset (name, 0, sizeof) to the screen, read (Stdin_fileno, name, sizeof ( name)); Wait for the user to enter the name to delete, assuming that the user entered the "Rice Island Love" Name[strlen (name)-1] = 0; Replace the last bit of the string with 0, and the last place is the integer 0 instead of the character ' 0 ' memset (SQL, 0, BUFSIZE), if (strlen (name) = = 0)//user does not have any input, just hit enter, the length is 0 {sprintf (SQL , "SELECT * from table2"); } else{sprintf (SQL, "select * from table2 WHERE name = '%s '", name);//}*/if (mysql_query (connection, SQL)! = 0) {printf ( The query Error,%s\n ", Mysql_error (&mysql));} Call Mysql_store_result to get the results of the query, the results are placed in the mysql_res structure mysql_res *result = Mysql_store_result (connection);// To know how many columns of the return dataset are free to use the various SELECT statements Mysql_field *field;int ifieldcount = 0;while (1) {FIELD = Mysql_fetch_field (result); The loop gets the column name, and if you loop to the end of the column, the function returns nullif (field = = NULL) break;printf ("%s\t", field->name); ifieldcount++;} printf ("\ n");//loop through each line Mysql_row Row;while (1) {row = Mysql_fetch_row (result); if (row = = NULL) Break;int i = 0;for (; i < Ifieldcount; i++) {printf ("%s\t", (const char *) row[i]);} printf ("\ n");} Mysql_free_result (result);} int main (int arg, char *args[]) {if (Arg < 4) return-1;mysql_init (&mysql);//equivalent to SQL internal initialization of a TCP socket, At the same time initialize the SQL must have memory and some structure//connect to MySQL serverconnection = Mysql_real_connect (&mysql, args[1], args[2], args[3], args[4],0, 0, 0); if (connection = = NULL) {printf ("Connect error,%s\n", Mysql_error (&mysql)); return-1;} if (mysql_query (connection, "set NAMES UTF8")! = 0)//sets the character set to utf8{printf ("Set charset error,%s\n", Mysql_error (&mysQL));} Char Buf[bufsize];memset (buf, 0, sizeof (BUF)), strcpy (buf, "select \n1: Insert \n2: Delete \n3: Modify \n4: Query \ n"); write (Stdout_fileno, buf , strlen (BUF)), memset (buf, 0, sizeof (BUF)), read (Stdin_fileno, buf, sizeof (BUF)), if (strncmp (buf, "4", 1) = = 0)// Input user input is 4{memset (buf, 0, sizeof (BUF)), strcpy (buf, "Please enter any SELECT statement"); write (Stdout_fileno, buf, strlen (BUF)); Memset ( BUF, 0, sizeof (BUF)); Read (Stdin_fileno, buf, sizeof (BUF)); Selectname (BUF);} Else{if (strncmp (buf, "1", 1) = = 0)//input user input is 1{insertname (BUF);} if (strncmp (buf, "2", 1) = = 0)//input user input is 2{deletename (BUF);} if (strncmp (buf, "3", 1) = = 0)//input user input is 3{updatename (BUF);} mysql_query (connection, buf);} Mysql_close (connection);//Disconnects the connection to SQL Server puts ("!!! Hello world!!! "); /* Prints!!! Hello World!!! */return exit_success;}


(18) Database programming--c language Operations database

Related Article

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.