How to use C language to correctly read MySQL database

The following articles mainly describe the actual operation process of reading the MySQL database in C language. If you are interested in the correct operation process of reading the MySQL database in C language, the following articles will satisfy your curiosity.

Recently, we learned about C development in the linux operating system. Haha, I wrote a test program to read MySQL Data and display it. Tested successfully...

 
 

  
  
#include <stdio.h> 
  
  
#include <stdlib.h> 
  
  
#include <MySQL.h> 
  
  
#define DB_SERVER ""  
  
  
#define DB_NAME "test"  
  
  
#define DB_USER "root"  
  
  
#define DB_PWD ""  
  
  
static MySQL *db_handel,MySQL;  
  
  
static MySQL_ROW row;  
  
  
static int query_error;  
  
  
MySQL_RES *query_test(char *sql);  
  
  
int query_show(MySQL_RES *result);  
  
  
int main(int argc,char *argv[])  
  
  
{  
  
  
MySQL_RES * results;  
  
  
results=query_test("select * from test");  
 
 

Retrieve records

 
 

  
  
query_show(results); 
 
 

Show records

 
 

  
  
return 0;  
  
  
} 
 
 

Query records

 
 

  
  
MySQL_RES *query_test(char *sql)  
  
  
{  
  
  
static MySQL_RES *query_result;  
  
  
printf("%s\n",sql);  
  
  
MySQL_init(&MySQL);  
  
  
db_handel=MySQL_real_connect(&MySQL,DB_SERVER,DB_USER,DB_PWD,DB_NAME,0,0,0); 
 
 

Open the connection to read the MySQL database

 
 

  
  
if(db_handel==NULL) 
 
 

Error Handling

{

 
 

  
  
printf(MySQL_error(&MySQL));  
  
  
return NULL;  
  
  
}  
  
  
query_error=MySQL_query(db_handel,sql);  
 
 

Query

 
 

  
  
if(query_error!=0) 
 
 

Error Handling

 
 

  
  
{  
  
  
printf(MySQL_error(db_handel));  
  
  
return NULL;  
  
  
}  
  
  
query_result=MySQL_store_result(db_handel); 
 
 

Retrieve records

 
 

  
  
MySQL_close(db_handel); 
 
 

Close Database

 
 

  
  
return query_result; 
 
 

Return record

 
 

  
  
} 
 
 

Show records

 
 

  
  
int query_show(MySQL_RES *result)  
  
  
{  
  
  
unsigned int i,num_fields;  
  
  
MySQL_FIELD *fileds;  
  
  
num_fields=MySQL_num_fields(result);  
 
 

Obtain the number of fields

 
 

  
  
fileds= mysql _fetch_fields(result); 
 
 

Get field array

 
 

  
  
while((row=mysql_fetch_row(result))!=NULL) 
 
 

Loop display

 
 

  
  
{  
  
  
for(i=0;i<num_fields;i++)  
  
  
{  
  
  
printf("%s: %s \n",fileds[i].name,row[i]?row[i]:"NULL");  
  
  
}  
  
  
}  
  
  
return 0;  
  
  
} 
 
 

The contents of MakeFile are as follows:

 
 

  
  
CC=gcc 
  
  
#LDLIBS=`gtk-config --libs --cflags`  
  
  
LDLIBS=-L /usr/lib/mysql -I /usr/include/mysql -l mysqlclient  
  
  
CFLAGS=-Wall -g`gtk-config --cflags`  
  
  
window:window.c  
  
  
$(CC) $(LDLIBS) window.c -o window  
  
  
#window.o:window.c  
  
  
# $(CC) $(LDLIBS) -c window.c  
  
  
clean:  
  
  
rm -f window  
  
  
rm -f *.o  
 
 

The above content is an introduction to reading Mysql from the C language. I hope you will get some benefits.