适合嵌入式linux方面的数据库SQLite3

SQLite3是一个开源的嵌入式数据库引擎，它实现了多数的SQL92标准，并且只占用很少的资源。它通过API进行访问，并且在许多嵌入式产品中使用。

以下是一些SQLite3在嵌入式Linux项目中的应用：

1. 创建/打开数据库：

#include <sqlite3.h>
 
int main(int argc, char* argv[])
{
    sqlite3 *db;
    char *zErrMsg = 0;
    int rc;
 
    rc = sqlite3_open("test.db", &db);
 
    if( rc ){
        fprintf(stderr, "Can't open database: %s\n", sqlite3_errmsg(db));
        sqlite3_close(db);
        return(0);
    }else{
        fprintf(stderr, "Opened database successfully\n");
    }
    sqlite3_close(db);
    return 0;
}

2. 执行SQL命令：

#include <sqlite3.h>
 
static int callback(void *NotUsed, int argc, char **argv, char **azColName)
{
    for(int 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;
 
    rc = sqlite3_open("test.db", &db);
 
    if( rc ){
        fprintf(stderr, "Can't open database: %s\n", sqlite3_errmsg(db));
        sqlite3_close(db);
        return(0);
    }else{
        fprintf(stderr, "Opened database successfully\n");
    }
 
    sql = "CREATE TABLE COMPANY(" \
          "ID INTEGER PRIMARY KEY AUTOINCREMENT," \
          "NAME TEXT NOT NULL," \
          "AGE INTEGER NOT NULL," \
          "ADDRESS CHAR(50)," \
          "SALARY REAL );";
 
    rc = sqlite3_exec(db, sql, callback, 0, &zErrMsg);
    if( rc != SQLITE_OK ){
        fprintf(stderr, "SQL error: %s\n", zErrMsg);
        sqlite3_free(zErrMsg);
    }
    sqlite3_close(db);
    return 0;
}

3. 使用参数化查询：

#include <sqlite3.h>
 
int main(int argc, char* argv[])
{
    sqlite3 *db;
    char *zErrMsg = 0;
    int rc;
    char *sql;
    sqlite3_stmt *res;
 
    rc = sqlite3_open("test.db", &db);
 
    if( rc ){
        fprintf(stderr, "Can't open database: %s\n", sqlite3_errmsg(db));
        sqlite3_close(db);
        return(0);
    }else{
        fprintf(stderr, "Opened database successfully\n");
    }
 
    sql = "INSERT INTO COMPANY (ID, NAME, AGE, ADDRESS, SALARY) " \
          "VALUES (?, ?, ?, ?, ?);";
 
    rc = sqlite3_prepare_v2(db, sql, -1, &res, 0);
 
    if( rc != SQLITE_OK ){
        fprintf(stderr, "Failed to prepare statement: %s\n", sqlite3_errmsg(db));
        sqlite3_close(db);
        return 0;
    }
 
    sqlite3_bind_int(res,