C语言连接GaussDB T数据库执行SQL语句

华为GaussDB T数据库支持C-API，本文介绍使用C连接GaussDB T数据库，并执行insert语句。
c语言使用起来非常方便，在初始化数据、测试数据、压测、二次开发等都可以直接用c来完成，提升效率。

1、下载gaussdb T C语言客户端：
gaussdb_c_client.tar.gz : https://www.modb.pro/download/3533
ps:安装包内也包含了相关客户端的驱动。

2、解压客户端文件：

tar zxvf GaussDB_100_1.0.0-CLIENT-C-REDHAT-64bit.tar.gz
mv GaussDB_100_1.0.0-CLIENT-C-REDHAT-64bit CLIENT-C

3、编辑gauss_conn_test.c程序:

#include <stdio.h>#include "/home/omm/c_gauss/CLIENT-C/include/gsc.h"int test_conn_db(char * url, char * user, char * password){    gsc_stmt_t gsc_stmt = NULL;    gsc_conn_t gsc_conn = NULL;    
    //alloc connection
    if (gsc_alloc_conn(&gsc_conn) != GSC_SUCCESS)
    {        return GSC_ERROR;
    }    //connect
    if (gsc_connect(gsc_conn, url, user, password) != GSC_SUCCESS)
    {        printf("connect failed\n");        return GSC_ERROR;
    }    //alloc stmt
    if (gsc_alloc_stmt(gsc_conn, &gsc_stmt) != GSC_SUCCESS)
    {        printf("alloc_stmt failed\n");        return GSC_ERROR;
    }    //insert test data
    if (gsc_prepare(gsc_stmt, "insert into steven_test values (3,'gauss','modb')") != GSC_SUCCESS)
    {        printf("prepare failed\n");        return GSC_ERROR;
    }    if (gsc_execute(gsc_stmt) != GSC_SUCCESS)
    {        printf("execute failed\n");        return GSC_ERROR;
    }    if (gsc_commit(gsc_conn) != GSC_SUCCESS)
    {        return GSC_ERROR;
    }    //disconnect from gaussdb
    gsc_free_stmt(gsc_stmt);
    gsc_disconnect(gsc_conn);
    gsc_free_conn(gsc_conn);    //to avoid using wild pointer, user should set conn NULL after free
    gsc_stmt = NULL;
    gsc_conn = NULL; 
    return GSC_SUCCESS;
}void main(){    int result = test_conn_db("127.0.0.1:1888", "steven", "modb123$");    return;
}

4、编译c文件：

gcc -o gauss_conn_test gauss_conn_test.c -L/home/omm/c_gauss/CLIENT-C/lib  -lzeclient

5、运行c程序：

./gauss_conn_test

6、使用watch重复运行c程序：

#也可以使用其他方式watch ./gauss_conn_test

Every 2.0s: ./gauss_conn_test

7、查看结果：

zsql SYS/Changeme_123@127.0.0.1:1888 -q

connected.

SQL> select * from steven.steven_test;

ID                                       CLASS_NAME                     NAME                                              
---------------------------------------- ------------------------------ --------------------------------------------------1                                        222                            steven                                            
1                                        222                            steven                                            
1                                        222                            steven                                            
1                                        222                            steven                                            
1                                        222                            steven                                            
1                                        222                            steven                                            
2                                                                                                                         
2                                                                                                                         
3                                        data                           modb                                              
2                                                                                                                         
2                                                                                                                         
2                                                                                                                         
3                                        gauss                          modb                                              
3                                        gauss                          modb                                              
3                                        gauss                          modb                                              
3                                        gauss                          modb                                              
3                                        gauss                          modb                                              
3                                        gauss                          modb                                              
3                                        gauss                          modb                                              
3                                        gauss                          modb                                              

20 rows fetched.

转自墨天轮