sqlite3 c语言样例

下面的样例是来自 博客 的代码。不过博主主要是用得windows，我这里使用linux做基础来完成样例的说明。

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

int MyCallback(void *para, int nColumn, char **colValue, char **colName); //回调函数

int main(int argc, char *argv[]){
    sqlite3 *db = NULL;
    int result = sqlite3_open("test.db", &db);

    if (result != SQLITE_OK)
    {
        printf("open database text.db failed \n");
        return 0;
    }else{
        printf("open database text.db success \n");
    }
    开始执行sqlite
    const char *sql = "create table Student(t_id integer primary key autoincrement, t_name varchar(15), t_age integer)";
    char *errMsg = NULL;
    result = sqlite3_exec(db,
                          sql,
                          NULL,
                          NULL,
                          &errMsg);
    if (result != SQLITE_OK){
        printf("create table Student failed\n");
        printf("error conde %d \t error message:%s", result, errMsg);
    }
    //插入数据
    errMsg = NULL;
    sql = "insert into Student(t_name, t_age) values ('dwb', 23)";
    result = sqlite3_exec(db,
                          sql,
                          NULL,
                          NULL,
                          &errMsg);
    printf("insert message1:%s \n", errMsg);

    errMsg = NULL;
    sql = "insert into Student(t_name, t_age) values ('dhx', 25)";
    result = sqlite3_exec(db,
                          sql,
                          NULL,
                          NULL,
                          &errMsg);
    printf("insert message2:%s \n", errMsg);

    errMsg = NULL;
    sql = "insert into Student(t_name, t_age) values ('dwz', 21)";
    result = sqlite3_exec(db,
                          sql,
                          NULL,
                          NULL,
                          &errMsg);
    printf("insert message3:%s \n", errMsg);

    
    errMsg = NULL;
    sql = "select * from Student;";
    result = sqlite3_exec(db, sql, MyCallback, NULL, &errMsg);
    printf("select message:%s \n", errMsg);

    //执行不用回调函数的sql语句，先要设置函数所需的参数
    printf("\nUSEING sqlite3_get_table()----------------------------\n");
    sql = "select * from Student;";

    int nCols;
    int nRows;
    char **azResult;
    errMsg = NULL;
    int index = 0;

    result = sqlite3_get_table(db, sql, &azResult, &nRows, &nCols, &errMsg);
    printf("result = %d \t errMsg = %s \n", result, errMsg);
    printf("rows:%d \t cols: %d \n", nRows, nCols);
    index = nCols;

    printf("++++++++++++++++++++++++++++++++++++++++++++++++++++++++\n");
    for (int i = 0; i < nRows; i++){
        for (int j = 0; j < nCols; j++){
            printf("%s::%s", azResult[j], azResult[index]);
            index++;
            printf("\n");
        }
    }
    printf("++++++++++++++++++++++++++++++++++++++++++++++++++++++++\n");

    sqlite3_free_table(azResult);
    sqlite3_close(db);
}

int MyCallback(void *para, int nColumn, char **colValue, char **colName)
{
    printf("----------------------------------------------------\n");
    printf("包含的列数：%d\n", nColumn);
    for (int i = 0; i < nColumn; i++){
        printf("%s :%s\n", *(colName + i), colValue[i]); //指针和数组的两种写法
    }
    printf("----------------------------------------------------\n");
    return 0;
}

将项目的代码保存为 main.c。

另外，我们要在官网 上下载sqlite3的项目源代码。
将sqlite3.c 和sqlite3.h 复制到我们的项目文件下。

然后，编译过程是:

gcc     main.c sqlite3.c   -o sqlite -ldl -pthread

运行：

$ ./sqlite 
open database text.db success 
insert message1:(null) 
insert message2:(null) 
insert message3:(null) 
----------------------------------------------------
包含的列数：3
t_id :1
t_name :dwb
t_age :23
----------------------------------------------------
----------------------------------------------------
包含的列数：3
t_id :2
t_name :dhx
t_age :25
----------------------------------------------------
----------------------------------------------------
包含的列数：3
t_id :3
t_name :dwz
t_age :21
----------------------------------------------------
select message:(null) 

USEING sqlite3_get_table()----------------------------
result = 0       errMsg = (null) 
rows:3   cols: 3 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++
t_id::1
t_name::dwb
t_age::23
t_id::2
t_name::dhx
t_age::25
t_id::3
t_name::dwz
t_age::21
++++++++++++++++++++++++++++++++++++++++++++++++++++++++

在linux下面使用还是很方便。