sqlite3数据库c语言常用接口应用实例



#include <stdio.h>
#include <string.h>
#include <sqlite3.h>

/***************************
typedef int (*sqlite3_callback)(
void*,// Data provided in the 4th argument of sqlite3_exec()
int,// The number of columns in row 
char**,// An array of strings representing fields in the row 
char**    // An array of strings representing column names 
);

***************************/

/* callback函数只有在对数据库进行select,操作时才会调用 */
static int select_callback(void *data,int argc,char **argv,char **azColName){
   int i;
   printf("%s",(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;

   /* 数据库创建或打开 */
   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");
   }

   char* sql;
   sql = "create table healthinfo (" \
           "sid int primary key not null," \
           "name text not null," \
           "ishealth char(4) not null);";

   /* 创建表 */
   rc = sqlite3_exec(db,sql,NULL,&zErrMsg);
   if( rc != sqlITE_OK ){
      fprintf(stderr,"sql error: %s\n",zErrMsg);
      sqlite3_free(zErrMsg);
   }else{
      fprintf(stdout,"Table created successfully\n");
   }

   sql = "insert into healthinfo (sid,name,ishealth)" \
           "values (201601001,'xiaowang','yes');" \
           "insert into healthinfo (sid,ishealth)" \
           "values (201601002,'xiaoli',ishealth)" \
           "values (201601003,'xiaozhang','no');" \
           "insert into healthinfo (sid,ishealth)" \
           "values (201601004,'xiaozhou',ishealth)" \
           "values (201601005,'xiaosun','yes');";

    /* 插入数据 */
   rc = sqlite3_exec(db,"Table insert data successfully\n");
   }

   char* strname = "xiaoyang";
   //char strname[256] = {'x','i','a','o','y','n','g'};
   char sql2[256] = {'0'};
   /* 不推荐使用这种方式 */
   sprintf(sql2,"insert into healthinfo (sid,ishealth) values (201601006,'%s','yes');",strname);
    /* 插入数据 */
   rc = sqlite3_exec(db,sql2,"Table insert data successfully\n");
   }

   /***********  存数据和取数据的第二种方法***********/
  
   sql = "insert into healthinfo (sid,ishealth)" \
           "values (:sid,:name,:ishealth);";   /* 注: ":sid" 为命名参数 也可以用? 号*/

   sqlite3_stmt *stmt;
   /* 准备一个语句对象 */
   sqlite3_prepare_v2(db,strlen(sql),&stmt,NULL); 
   /* 语句对象绑定的参数个数也就是上面sql语句values括号中的参数 */
   printf("max_parameter_count = %d\n",sqlite3_bind_parameter_count(stmt));
   /* 只有上面指定了:sid这个名字才可以用 */
   printf("sid parameter index = %d\n",sqlite3_bind_parameter_index(stmt,":sid")); 
   printf("name parameter index = %d\n",":name"));
   printf("ishealth parameter index = %d\n",":ishealth"));
   /* 如果是?号命名的则返回的文本为null */
   printf("index = 1 's parameter's name = %s\n",sqlite3_bind_parameter_name(stmt,1)); 
   sqlite3_bind_int(stmt,1,201601007);
   sqlite3_bind_text(stmt,2,"xiaoqian",-1,NULL); /* 第四个参数设为负数则自动计算第三个参数的长度 */
   sqlite3_bind_text(stmt,3,"yes",NULL);
   //sqlite3_bind_blob(stmt,sectionData,4096,sqlITE_STATIC); /* 将sectonData 绑定到stmt对象 */
   
   /* 执行sql 语句对象并判断其返回值
       发现如果不是select 这样会产生结果集的操作
       返回值为sqlITE_DONE 或者出错，只有执行sql语句会产生
       结果集执行step函数才返回sqlITE_ROW*/
   rc = sqlite3_step(stmt);  
   printf("step() return %s\n",rc == sqlITE_DONE ? "sqlITE_DONE" \
                                          : rc == sqlITE_ROW ? "sqlITE_ROW" : "sqlITE_ERROR");

    sqlite3_reset(stmt);  /* 如果要重新绑定其他值要reset一下 */
    sqlite3_bind_int(stmt,201601008);
    sqlite3_bind_text(stmt,"xiaowu",NULL); /* 重新绑定值 */
    sqlite3_bind_text(stmt,NULL);
    sqlite3_step(stmt);  /* 再执行 */
   
   /* 销毁prepare 创建的语句对象 */
   sqlite3_finalize(stmt);  

   /* 取数据 */
   //sql = "select * from healthinfo;";
   sql = "select * from healthinfo limit 4 offset 2;";  /* 限制返回4行且从第3行开始 */
   sqlite3_prepare_v2(db,NULL);
   printf("total_column = %d\n",sqlite3_column_count(stmt));
   
   /* 遍历执行sql语句后的结果集的每一行数据 */
   while(sqlite3_step(stmt) == sqlITE_ROW){
       /* 获得字节数，第二个参数为select结果集合的列号 */
       /* 由于select 的结果集只有section这一列，因此为0 */
       int len_sid = sqlite3_column_bytes(stmt,0);
       int len_name = sqlite3_column_bytes(stmt,1);
       int len_ishealth = sqlite3_column_bytes(stmt,2);
       
       printf("sid = %d,len = %d\n",sqlite3_column_int(stmt,0),len_sid);
       printf("name = %s,sqlite3_column_text(stmt,1),len_name);
       printf("ishealth = %s,2),len_ishealth);
       //unsigned char* srcdata = sqlite3_column_blob(stmt,0);  /* 取得数据库中的blob数据 */
   }
   printf("\n");
   sqlite3_finalize(stmt);
   /******************* end ****************************/
   

   const char* data = "select call back function call!\n";
   /* select 使用*/
   sql = "select * from healthinfo where ishealth == 'yes';";
   rc = sqlite3_exec(db,select_callback,data,"Table select successfully\n");
   }

   data = "update call back function call!\n";
   /* update 使用*/
   sql = "update healthinfo set ishealth = 'no' where name='xiaoli';" \
            "select * from healthinfo where ishealth == 'yes';";
   rc = sqlite3_exec(db,"Table update successfully\n");
   }
   
   
   /* 删除表 */
   sql = "drop table healthinfo;";
   rc = sqlite3_exec(db,"Table droped successfully\n");
   }


   char sql5[256];
   char* tname = "abc";
   sprintf(sql5,"create table if not exists %s ("\
                    "id int not null," \
                    "name text not null);",tname);

   printf("%s\n",sql5);

   /* 创建表 */
   rc = sqlite3_exec(db,sql5,"Table created successfully\n");
   }
   
   sqlite3_close(db);
}

学了一天的sqlite3编程，学习用例贴出来，基本的函数都用到了，也进行了详细的说明，希望对看的人有帮助。