linux_sqlite3学习

来源：互联网发布：存储数据的最小单位编辑：程序博客网时间：2024/06/11 20:38

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

#include <sqlite3.h>

int callback(void *arg, int clu_num, char **value, char **name)
{
    int i = 0;
    for(i; i <= clu_num-1; i++)
    {
       printf("字段名:%s 值:%s\n", name[i], value[i]);
    }
    return 0;
}

int main()
{
    //1、创建sqlite3 操纵对象
    struct sqlite3 *db=NULL;
    char *errbuf = (char *)malloc(200);
    do
    {
        //2、打开或创建数据库
        int ret = -1;
        if( 0 != (ret=sqlite3_open("taoli.db",&db)) )
        {
            goto err;
        }
        //3、执行sql命令
        if( SQLITE_OK != sqlite3_exec(db, "create table student(id INTEGER PRIMARY KEY, name TEXT);", NULL, NULL, &errbuf) )
        {
            printf("exec create err info:\n%s\n", errbuf);
            goto err;
        }
        if( SQLITE_OK != sqlite3_exec(db, "insert into student values (1, 'tanziqi');", NULL, NULL, &errbuf) )
        {
            printf("exec insert err info:\n%s\n", errbuf);
            goto err;
        }
        if( SQLITE_OK != sqlite3_exec(db, "select * from student;", callback, NULL, &errbuf) )
        {
            printf("exec select err info:\n%s\n", errbuf);
            goto err;
        }
        //4、其它业务逻辑
        //5、关闭数据库,清理缓冲区等资源
        sqlite3_free(errbuf);
        sqlite3_close(db);
    }while(0);
    return 0;
err:
    sqlite3_free(errbuf);
    sqlite3_close(db);
    printf("failed\n");
    exit(1);
}

//==============================================示例二==================================================================

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

#include <set>

#include "sqlite3.h"

using namespace std;

std::set<int> g_id;
std::set<char *> g_name;

int main()
{
    //1、创建sqlite3 操纵对象及错误信息缓冲区
    char *errbuf = NULL;//
    struct sqlite3 *db=NULL;
    do
    {
        //2、打开或创建数据库
        int ret = -1;
        if( 0 != (ret=sqlite3_open("taoli.db",&db)) )
        {
            goto err;
        }
        //3、执行sqlite3_get_table //下标0~(pcolumn-1)的是字段名 pcolumn~(prow-1)是对应的第一行结果集
        char **pdata;
        int prow = 0, pcolumn = 0;
        if(SQLITE_OK != sqlite3_get_table(db, "select * from student;", &pdata, &prow, &pcolumn, &errbuf))
        {
            printf("err info:\n%s\n", errbuf);
            goto err;
        }
        //4、业务逻辑
        printf("字段名 [%s] [%s]\n" , pdata[0], pdata[1]);
        printf("值:%s    %s\n", pdata[2], pdata[3]);
        //5、释放结果集资源free_table
        sqlite3_free_table(pdata);
        //6、关闭数据库(释放句柄与错误缓冲区)
        sqlite3_free(errbuf);
        sqlite3_close(db);
    }while(0);
    return 0;
err:
    sqlite3_free(errbuf);
    sqlite3_close(db);
    return -1;
}

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