与SQL Server一样，将PostgreSQL bytea转换为Base64

import psycopg2
import base64

# 连接到 PostgreSQL 数据库
conn = psycopg2.connect(database="yourdb", user="youruser", password="yourpassword", host="yourhost", port="yourport")
cur = conn.cursor()

# 查询 bytea 数据
cur.execute("SELECT your_bytea_column FROM your_table WHERE id = %s", (1,))
bytea_data = cur.fetchone()[0]

# 将 bytea 数据转换为 Base64 编码
base64_data = base64.b64encode(bytea_data).decode('utf-8')

print("Base64 Encoded Data:", base64_data)

# 关闭连接
cur.close()
conn.close()

// 假设你已经从后端获取了 Base64 编码的数据
const base64Data = "your_base64_encoded_data";

// 将 Base64 数据解码为二进制数据
const binaryData = atob(base64Data);

// 将二进制数据转换为 Uint8Array
const uint8Array = new Uint8Array(binaryData.length);
for (let i = 0; i < binaryData.length; i++) {
    uint8Array[i] = binaryData.charCodeAt(i);
}

console.log("Binary Data:", uint8Array);

# 分块处理大文件
def encode_large_file(file_path):
    with open(file_path, 'rb') as file:
        while chunk := file.read(1024):
            yield base64.b64encode(chunk).decode('utf-8')