C语言实现MySQL数组插入技巧

MySQL是一款流行的关系型数据库管理系统，它提供了多种语言接口，包括C语言。本文将介绍如何在C语言中使用MySQL C API实现批量插入数据到MySQL数据库中。

1. 创建表格

首先需要创建一个表格用于存储数据。可以使用下面的命令在MySQL命令行中创建一个名为student的表格。

“`sql

CREATE TABLE student (

id INT NOT NULL AUTO_INCREMENT,

name VARCHAR(30) NOT NULL,

age INT NOT NULL,

PRIMARY KEY (id)

);

2. 连接到MySQL

在C语言中连接到MySQL可以使用MySQL C API提供的函数。下面是连接到本地MySQL服务器并指定数据库的示例代码。

```c
#include 
int mn() {
  MYSQL *conn;
  conn = mysql_init(NULL);

  if (conn == NULL) {
    printf("mysql_init() fled\n");
    exit(1);
  }
  if (mysql_real_connect(conn, "localhost", "username", "password", "database", 0, NULL, 0) == NULL) {
    printf("mysql_real_connect() fled: %s\n", mysql_error(conn));
    exit(1);
  }
  printf("Connected to MySQL\n");

  mysql_close(conn);

  return 0;
}

3. 插入数据

插入单条记录可以使用下面的代码。

“`c

MYSQL *conn;

MYSQL_STMT *stmt;

MYSQL_BIND param[2];

char *name = “张三”;

int age = 18;

conn = mysql_init(NULL);

mysql_real_connect(conn, “localhost”, “username”, “password”, “database”, 0, NULL, 0);

stmt = mysql_stmt_init(conn);

if (mysql_stmt_prepare(stmt, “INSERT INTO student (name, age) VALUES (?, ?)”, 41) != 0) {

printf(“mysql_stmt_prepare() fled: %s\n”, mysql_stmt_error(stmt));

exit(1);

}

memset(param, 0, sizeof(param));

param[0].buffer_type = MYSQL_TYPE_STRING;

param[0].buffer = name;

param[0].buffer_length = strlen(name);

param[1].buffer_type = MYSQL_TYPE_LONG;

param[1].buffer = &age;

if (mysql_stmt_bind_param(stmt, param) != 0) {

printf(“mysql_stmt_bind_param() fled: %s\n”, mysql_stmt_error(stmt));

exit(1);

}

if (mysql_stmt_execute(stmt) != 0) {

printf(“mysql_stmt_execute() fled: %s\n”, mysql_stmt_error(stmt));

exit(1);

}

mysql_stmt_close(stmt);

mysql_close(conn);

批量插入多条记录可以使用下面的代码。需要注意的是，在循环中重复准备SQL语句可能会降低效率，可以使用mysql_stmt_reset()函数重置语句句柄。

```c
MYSQL *conn;
MYSQL_STMT *stmt;
MYSQL_BIND param[2];
char *names[] = {"张三", "李四", "王五"};
int ages[] = {18, 19, 20};
unsigned long name_lengths[] = {strlen(names[0]), strlen(names[1]), strlen(names[2])};
unsigned long *param_lengths[] = {&name_lengths[0], &name_lengths[1], &name_lengths[2]};
int i;

conn = mysql_init(NULL);
mysql_real_connect(conn, "localhost", "username", "password", "database", 0, NULL, 0);
stmt = mysql_stmt_init(conn);

if (mysql_stmt_prepare(stmt, "INSERT INTO student (name, age) VALUES (?, ?)", 41) != 0) {
  printf("mysql_stmt_prepare() fled: %s\n", mysql_stmt_error(stmt));
  exit(1);
}
memset(param, 0, sizeof(param));
param[0].buffer_type = MYSQL_TYPE_STRING;
param[0].buffer = names[0];
param[0].buffer_length = name_lengths[0];
param[1].buffer_type = MYSQL_TYPE_LONG;
param[1].buffer = &ages[0];
if (mysql_stmt_bind_param(stmt, param) != 0) {
  printf("mysql_stmt_bind_param() fled: %s\n", mysql_stmt_error(stmt));
  exit(1);
}
for (i = 0; i 
  name_lengths[i] = strlen(names[i]);
  param[0].buffer = names[i];
  param[0].buffer_length = name_lengths[i];
  param[0].length = param_lengths[i];
  param[1].buffer = &ages[i];
  if (mysql_stmt_execute(stmt) != 0) {
    printf("mysql_stmt_execute() fled: %s\n", mysql_stmt_error(stmt));
    exit(1);
  }
  mysql_stmt_reset(stmt);
}
mysql_stmt_close(stmt);
mysql_close(conn);

4. 总结

本文介绍了如何使用C语言实现MySQL数组插入技巧，包括创建表格、连接到MySQL、插入数据等方面的内容。这些技巧可以帮助C语言程序员更好地使用MySQL C API，提高程序的效率和可靠性。