C语言中数据库怎么连接C语言MySQL接口的调用方法

#include <stdio.h>
#include <mysql/mysql.h>

MYSQL *conn = mysql_init(NULL);
if (conn == NULL) {
    fprintf(stderr, "mysql_init() failed\n");
    return 1;
}

if (mysql_real_connect(conn, "localhost", "username", "password", "database_name", 0, NULL, 0) == NULL) {
    fprintf(stderr, "mysql_real_connect() failed\n%s\n", mysql_error(conn));
    mysql_close(conn);
    return 1;
}

if (mysql_query(conn, "SELECT * FROM your_table")) {
    fprintf(stderr, "mysql_query() failed\n%s\n", mysql_error(conn));
    mysql_close(conn);
    return 1;
}

MYSQL_RES *result = mysql_store_result(conn);
if (result == NULL) {
    fprintf(stderr, "mysql_store_result() failed\n%s\n", mysql_error(conn));
    mysql_close(conn);
    return 1;
}

int num_fields = mysql_num_fields(result);
MYSQL_ROW row;

while ((row = mysql_fetch_row(result))) {
    for (int i = 0; i < num_fields; i++) {
        printf("%s ", row[i] ? row[i] : "NULL");
    }
    printf("\n");
}

mysql_free_result(result);

mysql_close(conn);

MYSQL_STMT *stmt = mysql_stmt_init(conn);
if (!stmt) {
    fprintf(stderr, "mysql_stmt_init(), out of memory\n");
    mysql_close(conn);
    return 1;
}

const char *query = "SELECT * FROM users WHERE username = ? AND password = ?";
if (mysql_stmt_prepare(stmt, query, strlen(query))) {
    fprintf(stderr, "mysql_stmt_prepare(), %s\n", mysql_stmt_error(stmt));
    mysql_close(conn);
    return 1;
}

MYSQL_BIND bind[2];
memset(bind, 0, sizeof(bind));

char username[50] = "user_input"; // 假设这是用户输入
char password[50] = "password_input"; // 假设这是用户输入

bind[0].buffer_type = MYSQL_TYPE_STRING;
bind[0].buffer = username;
bind[0].buffer_length = 50;

bind[1].buffer_type = MYSQL_TYPE_STRING;
bind[1].buffer = password;
bind[1].buffer_length = 50;

if (mysql_stmt_bind_param(stmt, bind)) {
    fprintf(stderr, "mysql_stmt_bind_param(), %s\n", mysql_stmt_error(stmt));
    mysql_close(conn);
    return 1;
}

if (mysql_stmt_execute(stmt)) {
    fprintf(stderr, "mysql_stmt_execute(), %s\n", mysql_stmt_error(stmt));
    mysql_close(conn);
    return 1;
}

// 获取结果...

mysql_stmt_close(stmt);

char query[200];
char escaped_username[50];
char escaped_password[50];

mysql_real_escape_string(conn, escaped_username, username, strlen(username));
mysql_real_escape_string(conn, escaped_password, password, strlen(password));

snprintf(query, sizeof(query), "SELECT * FROM users WHERE username = '%s' AND password = '%s'", escaped_username, escaped_password);

if (mysql_query(conn, query)) {
    fprintf(stderr, "mysql_query() failed\n%s\n", mysql_error(conn));
    mysql_close(conn);
    return 1;
}

[mysqld]
character-set-server=utf8mb4
collation-server=utf8mb4_unicode_ci

CREATE DATABASE database_name CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

CREATE TABLE table_name (
    ...
) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

if (mysql_set_character_set(conn, "utf8mb4")) {
    fprintf(stderr, "mysql_set_character_set() failed\n%s\n", mysql_error(conn));
    mysql_close(conn);
    return 1;
}