[C/C ++ school] (22) Mysql database programming-c language database operations, mysql-C

[C/C ++ school] (22) Mysql database programming-c language database operations, mysql-C

Makefile

.SUFFIXES: .c .oCC=gccSRCS=mysql1.cOBJS=$(SRCS:.c=.o)EXEC=mysql1all: $(OBJS)$(CC) -o $(EXEC) $(OBJS) -lmysqlclient@echo '-------------ok--------------'.c.o:$(CC) -Wall -g -o $@ -c $< clean:rm -f $(OBJS)rm -f core*

Mysql1.c

# Include <stdio. h> # include <stdlib. h> # include <unistd. h> # include <string. h> # include <errno. h> # include <termios. h> # include <mysql/mysql. h> # define BUFSIZE 1024 MYSQL 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 sentence replaces the printf function, in this way, the char name [1024]; memset (name, 0, sizeof (name); read (STDIN_FI LENO, name, sizeof (name); // wait for the user to enter the name to be deleted. Assume that the user entered "Rice island love" name [strlen (name)-1] = 0; // replace \ n, the last character of the string, with 0, with an integer 0 instead of '0' memset (SQL, 0, BUFSIZE); sprintf (SQL, "delete from table1 WHERE name = '% S'", name ); /// SQL = delete from table1 WHERE name = 'island ai' 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 sentence is replaced In this way, the char name [1024] can be output to the screen without \ n; memset (name, 0, sizeof (name); read (STDIN_FILENO, name, sizeof (name); // wait for the user to enter the name to be inserted. Assume that the user entered the name "Rice island love" name [strlen (name)-1] = 0; // replace \ n, the last character of the string, with 0, with an integer 0 instead of '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 sex to insert, s Ex [strlen (sex)-1] = 0; // replace \ n, the last character of the string, with 0 and the last integer 0, rather than 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 (age); read (STDIN_FILENO, age, sizeof (age )); // wait for the user to enter the age to insert [strlen (age)-1] = 0; // replace \ n with 0, the last value is an integer 0 instead of the character '0' memset (SQL, 0, BUFSIZE); sprintf (SQL, "% s", "Enter the class to be inserted>: "); write (STDOUT_FILENO, SQL, strl En (SQL); char classes [1024]; memset (classes, 0, sizeof (classes); read (STDIN_FILENO, classes, sizeof (classes )); // wait for the user to enter the class classes to be inserted [strlen (classes)-1] = 0; // replace \ n with 0, the last value is an 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 = 'island ai' printf ("'% s' \ n", SQL );} Void updatename (char * SQL) {memset (SQL, 0, BUFSIZE); sprintf (SQL, "% s", "Enter the name to modify> :"); write (STDOUT_FILENO, SQL, strlen (SQL); // This sentence replaces the printf function. In this way, the char name [1024] can be output to the screen without \ n. memset (name, 0, sizeof (name); read (STDIN_FILENO, name, sizeof (name); // wait for the user to enter the name to insert, assume that the user entered "Rice island love" name [strlen (name)-1] = 0; // replace \ n, the last character of the string, with an integer 0, rather than the character '0' memset (SQL, 0, BUFSIZE); sprintf (SQL, "% s", "Enter the gender to be gender>:"); 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 sex to be inserted. sex [strlen (sex)-1] = 0; // replace \ n, the last character of the string, with 0, with an integer 0 instead of '0' memset (SQL, 0, BUFSIZE); sprintf (SQL, "% s", "Enter age>:"); write (STDOUT_FILENO, SQL, strlen (SQL); char age [1024]; memset (age, 0, sizeof (age); read (STDIN_FILENO, age, sizeof (age); // wait for the user to enter the age to insert [strlen (age) -1] = 0; // replace \ n, the last character of the string, with 0 and the last integer 0 instead of '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 classes to be inserted [strlen (classes) -1] = 0; // replace \ n, the last character of the string, with 0 and the last integer 0 instead of '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 = 'island ai' printf ("'% s' \ n", SQL);} void selectname (const char * SQL) {/* char SQL [1024]; memset (SQL, 0, BUFSIZE); sprintf (SQL, "% s", "Enter the name to query> :"); write (STDOUT_FILENO, SQL, strlen (SQL); // This sentence replaces the printf function. In this way, the char name [1024] can be output to the screen without \ n. memset (name, 0, sizeof (name); read (STDIN_FILENO, name, sizeof (name ));/ /Wait for the user to enter the name to be deleted. Assume that the user entered "Rice island love" name [strlen (name)-1] = 0; // replace \ n, the last character of the string, with 0, with an integer 0 instead of '0' memset (SQL, 0, BUFSIZE); if (strlen (name) = 0) // the user does not have any input, just press enter and 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 ("query error, % s \ n", mysql_error (& mysql);} // call mysql_store_result to obtain the query result, put the result in the MYSQL_RES structure MYSQL_RES * result = mysql_store_result (connection); // you must know the number of columns in the returned dataset to use various SELECT statements MYSQL_FIELD * field freely; int iFieldCount = 0; while (1) {field = mysql_fetch_field (result); // The column name is obtained cyclically. If the column name is obtained at the end of the loop, the function returns NULLif (field = NULL) break; printf ("% s \ t", field-> name); iFieldCount ++;} printf ("\ n"); // cyclically traverse each row MYSQL_ROW row; whi Le (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 ); // It is equivalent to initializing a TCP socket in SQL, and initializing the memory and some structures required by SQL. // 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) // set the character set to UTF8 {printf ("set character set 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) // The input user inputs 4 {memset (buf, 0, sizeof (buf )); strcpy (buf, "enter any SELECt statement"); write (STDOUT_FILENO, buf, strlen (buf); memse T (buf, 0, sizeof (buf); read (STDIN_FILENO, buf, sizeof (buf); selectname (buf);} else {if (strncmp (buf, "1", 1) = 0) // The input user inputs 1 {insertname (buf);} if (strncmp (buf, "2", 1) = 0) // The input user inputs 2 {deletename (buf);} if (strncmp (buf, "3", 1) = 0) // The input user inputs 3 {updatename (buf);} mysql_query (connection, buf);} mysql_close (connection ); // disconnect from SQL server puts ("!!! Hello World !!! ");/* Prints !!! Hello World !!! */Return EXIT_SUCCESS ;}