linux cc++ 调mysql_stmt_prepare实现insert into emp enamehiredatesal values; enamehiredatesal字段是字符串和长度都只知道给出实现

下面是一个示例代码，演示了如何使用mysql_stmt_prepare函数实现插入语句：

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

int main() {
    MYSQL *conn;
    MYSQL_STMT *stmt;
    MYSQL_BIND bind[3];

    const char *query = "INSERT INTO emp (ename, hiredate, sal) VALUES (?, ?, ?)";
    const char *ename = "John";
    const char *hiredate = "2021-01-01";
    float sal = 5000.0;

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

    if (!mysql_real_connect(conn, "localhost", "user", "password", "database", 0, NULL, 0)) {
        fprintf(stderr, "mysql_real_connect failed: %s\n", mysql_error(conn));
        mysql_close(conn);
        return 1;
    }

    stmt = mysql_stmt_init(conn);
    if (!stmt) {
        fprintf(stderr, "mysql_stmt_init failed\n");
        mysql_close(conn);
        return 1;
    }

    if (mysql_stmt_prepare(stmt, query, strlen(query)) != 0) {
        fprintf(stderr, "mysql_stmt_prepare failed: %s\n", mysql_stmt_error(stmt));
        mysql_stmt_close(stmt);
        mysql_close(conn);
        return 1;
    }

    memset(bind, 0, sizeof(bind));

    bind[0].buffer_type = MYSQL_TYPE_STRING;
    bind[0].buffer = (char *)ename;
    bind[0].buffer_length = strlen(ename);
    bind[0].is_null = 0;
    bind[0].length = &bind[0].buffer_length;

    bind[1].buffer_type = MYSQL_TYPE_STRING;
    bind[1].buffer = (char *)hiredate;
    bind[1].buffer_length = strlen(hiredate);
    bind[1].is_null = 0;
    bind[1].length = &bind[1].buffer_length;

    bind[2].buffer_type = MYSQL_TYPE_FLOAT;
    bind[2].buffer = (char *)&sal;
    bind[2].is_null = 0;
    bind[2].length = 0;

    if (mysql_stmt_bind_param(stmt, bind) != 0) {
        fprintf(stderr, "mysql_stmt_bind_param failed: %s\n", mysql_stmt_error(stmt));
        mysql_stmt_close(stmt);
        mysql_close(conn);
        return 1;
    }

    if (mysql_stmt_execute(stmt) != 0) {
        fprintf(stderr, "mysql_stmt_execute failed: %s\n", mysql_stmt_error(stmt));
        mysql_stmt_close(stmt);
        mysql_close(conn);
        return 1;
    }

    mysql_stmt_close(stmt);
    mysql_close(conn);

    return 0;
}

请根据实际情况修改连接数据库的参数（主机名、用户名、密码、数据库名）。在这个示例中，ename和hiredate都是字符串，sal是浮点数。bind数组用于绑定参数，将参数的类型、值和长度设置为正确的值。然后使用mysql_stmt_bind_param函数将参数绑定到准备好的语句中，最后使用mysql_stmt_execute函数执行语句。

请注意，这只是一个示例，你需要根据你的具体需求进行修改和适配