sp3接着延续上一片讲update

Myth丶恋晨 2022-08-21 12:45 45阅读 0赞

## UPDATE 操作 ##

#include <stdio.h>
    #include <stdlib.h>
    #include <sqlite3.h> 
    
    static int callback(void *data, int argc, char **argv, char **azColName){
       
       int i;
       fprintf(stderr, "%s: ", (const char*)data);
       for(i=0; i<argc; i++){
       
          printf("%s = %s\n", azColName[i], argv[i] ? argv[i] : "NULL");
       }
       printf("\n");
       return 0;
    }
    
    int main(int argc, char* argv[])
    {
       
       sqlite3 *db;
       char *zErrMsg = 0;
       int rc;
       char *sql;
       const char* data = "Callback function called";
    
       /* Open database */
       rc = sqlite3_open("test.db", &db);
       if( rc ){
       
          fprintf(stderr, "Can't open database: %s\n", sqlite3_errmsg(db));
          exit(0);
       }else{
       
          fprintf(stderr, "Opened database successfully\n");
       }
    
       /* Create merged SQL statement */
       sql = "UPDATE COMPANY set SALARY = 25000.00 where ID=1; " \
             "SELECT * from COMPANY";
    
       /* Execute SQL statement */
       rc = sqlite3_exec(db, sql, callback, (void*)data, &zErrMsg);
       if( rc != SQLITE_OK ){
       
          fprintf(stderr, "SQL error: %s\n", zErrMsg);
          sqlite3_free(zErrMsg);
       }else{
       
          fprintf(stdout, "Operation done successfully\n");
       }
       sqlite3_close(db);
       return 0;
    }

上述程序编译和执行时，它会产生以下结果：

Opened database successfully
    Callback function called: ID = 1
    NAME = Paul
    AGE = 32
    ADDRESS = California
    SALARY = 25000.0
    
    Callback function called: ID = 2
    NAME = Allen
    AGE = 25
    ADDRESS = Texas
    SALARY = 15000.0
    
    Callback function called: ID = 3
    NAME = Teddy
    AGE = 23
    ADDRESS = Norway
    SALARY = 20000.0
    
    Callback function called: ID = 4
    NAME = Mark
    AGE = 25
    ADDRESS = Rich-Mond
    SALARY = 65000.0
    
    Operation done successfully