简单的数据库操作（表的创建。记录的插入，删除，显示）

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

int create_table(sqlite3*db)//创建表，未空的打开
{
char *errmsg = NULL;
char *sql;

sql = "create table if not exists mytable (id integer primary key,name text);";

if(SQLITE_OK != sqlite3_exec(db,sql,NULL,NULL,&errmsg))
{
printf("create table error!%s\n",errmsg);
exit(-1);
}

return 0;
}
int insert_records(sqlite3*db)//插入记录
{
char *errmsg = NULL;
char sql[100];
int id;
char name[10];
int num;
int i;
printf("enter number of records:");
scanf("%d",&num);

for(i=0;i<num;i++)
{
printf("enter a id:");
scanf("%d",&id);
printf("enter a name:");
scanf("%s",name);

sprintf(sql,"insert into mytable (id,name) values (%d,'%s');",id,name);

if(SQLITE_OK != sqlite3_exec(db,sql,NULL,NULL,&errmsg))
{
printf("insert error!%s\n",errmsg);
exit(-1);
}
}

return 0;

}
int displaycb(void*para,int col_count,char**col_value,char**col_name)//显示表记录的回调函数
{
int i;
printf("total num %d\n",col_count);

for(i = 0; i < col_count; i++)
{
printf("col_name:%s--->col_value:%s\n",col_name[i],col_value[i]);
}

printf("***********************\n");

return 0;
}
int inquire_usecb(sqlite3 *db)//显示表记录
{
char *errmsg = NULL;
char *sql;

sql = "select * from mytable;";

if(SQLITE_OK != sqlite3_exec(db,sql,displaycb,NULL,&errmsg))
{
printf("select error!%s\n",errmsg);
exit(-1);
}
return 0;

}

int delate_record(sqlite3 * db)//删除一行表记录
{
char *errmsg = NULL;
char sql[100];
int id;
printf("enter the dalate id:");
scanf("%d",&id);

sprintf(sql,"delete from mytable where id = %d;",id);

if(SQLITE_OK != sqlite3_exec(db,sql,NULL,NULL,&errmsg))
{
printf("select error!%s\n",errmsg);
exit(-1);
}

return 0;

}
int inquire_usegt(sqlite3*db)//显示表记录，用sqlite3_get_table函数
{
int row;
int column;
char **aresult;
char *errmsg = NULL;
char *sql;
int i;
sql = "select * from mytable;";

if(SQLITE_OK != sqlite3_get_table(db,sql,&aresult,&row,&column,&errmsg))
{
printf("select error!%s\n",errmsg);
exit(-1);
}

for(i = 0; i < (row + 1) * column ; i++)
{
printf("%10s",aresult[i]);
if((i + 1) % column == 0)
{
printf("\n");
}
}

sqlite3_free_table(aresult);

return 0;
}

int main()
{
sqlite3 * db = NULL;
int ret;

ret = sqlite3_open("mydatabase.db",&db);

if(ret != SQLITE_OK)
{
perror("open mydatabase.db error!\n");
exit(-1);
}
else
{
printf("open mydatabase.db successfully\n");
}

create_table(db);
insert_records(db);
inquire_usecb(db);
delate_record(db);
inquire_usegt(db);

sqlite3_close(db);

return 0;
}