Python psycopg2动态where子句，可选，基于条件

import psycopg2
from psycopg2 import sql

conn = psycopg2.connect(database="your_database", user="your_username", password="your_password", host="your_host", port="your_port")

cur = conn.cursor()

base_query = sql.SQL("SELECT * FROM your_table")
conditions = []

# 根据条件动态生成WHERE子句
if condition1:
    conditions.append(sql.SQL("column1 = {}").format(sql.Identifier(value1)))
if condition2:
    conditions.append(sql.SQL("column2 = {}").format(sql.Identifier(value2)))
# 添加更多条件...

# 构建完整的WHERE子句
if conditions:
    where_clause = sql.SQL("WHERE {}").format(sql.SQL(" AND ").join(conditions))
    query = sql.SQL("{base_query} {where_clause}").format(base_query=base_query, where_clause=where_clause)
else:
    query = base_query

cur.execute(query)
results = cur.fetchall()

cur.close()
conn.close()