Python 提取出SQL语句中Where的值两种方法(示例代码)

pip install sqlparse

import sqlparse  
from sqlparse.sql import IdentifierList, Identifier  
from sqlparse.tokens import Keyword, DML  
def extract_where_values(sql):  
    # 使用sqlparse解析SQL语句  
    parsed = sqlparse.parse(sql)[0]  
    # 提取WHERE子句  
    where_seen = False  
    for item in parsed.tokens:  
        if where_seen:  
            if is_subselect(item):  
                where_seen = False  
            else:  
                # 这里的item可能是WHERE子句的一部分  
                print(item)  
        elif item.ttype is Keyword and item.value.upper() == 'WHERE':  
            where_seen = True  
def is_subselect(parsed):  
    if not parsed.is_group:  
        return False  
    for item in parsed.tokens:  
        if item.ttype is DML and item.value.upper() == 'SELECT':  
            return True  
    return False  
# 示例SQL语句  
sql = """  
SELECT * FROM users  
WHERE id = 10 AND status = 'active' OR name = 'John Doe';  
"""  
extract_where_values(sql)

import re  
def extract_where_clause(sql):  
    # 使用正则表达式匹配WHERE子句  
    # 这个正则表达式假设WHERE子句在SQL语句中直接跟在SELECT, UPDATE, DELETE等之后  
    # 并且可能包含空格、换行符等  
    # 注意：这个正则表达式非常基础，可能无法处理所有情况  
    pattern = r'(?<=WHERE\s+)(.*?)(?=\s*(?:ORDER BY|GROUP BY|LIMIT|;|$))'  
    match = re.search(pattern, sql, re.IGNORECASE | re.DOTALL)  
    if match:  
        return match.group(0).strip()  
    else:  
        return "No WHERE clause found."  
# 示例SQL语句  
sql_examples = [  
    "SELECT * FROM users WHERE id = 10 AND name = 'John';",  
    "UPDATE users SET status = 'active' WHERE age > 30 AND status = 'inactive';",  
    "DELETE FROM orders WHERE order_date < '2023-01-01';",  
    "SELECT * FROM products;",  # 没有WHERE子句  
    "SELECT * FROM products WHERE (price > 100 OR quantity < 10) AND category = 'Electronics';"  
]  
# 遍历示例并打印结果  
for sql in sql_examples:  
    print(f"Original SQL: {sql}")  
    print(f"Extracted WHERE Clause: {extract_where_clause(sql)}\n")

import re  
def extract_where_clause(sql):  
    """  
    从SQL语句中提取WHERE子句的内容。  
    参数:  
    sql (str): SQL查询语句。  
    返回:  
    str: 提取的WHERE子句内容（如果存在），否则返回"No WHERE clause found."。  
    """  
    # 使用正则表达式匹配WHERE子句  
    # 这个正则表达式尝试匹配WHERE关键字后直到遇到SQL语句结束或特定SQL子句开始的位置  
    pattern = r'(?<=WHERE\s+)(.*?)(?=\s*(?:ORDER BY|GROUP BY|LIMIT|;|$))'  
    match = re.search(pattern, sql, re.IGNORECASE | re.DOTALL)  
    if match:  
        return match.group(0).strip()  
    else:  
        return "No WHERE clause found."  
# 完整的Python脚本  
if __name__ == "__main__":  
    # 示例SQL语句  
    sql_examples = [  
        "SELECT * FROM users WHERE id = 10 AND name = 'John';",  
        "UPDATE users SET status = 'active' WHERE age > 30 AND status = 'inactive';",  
        "DELETE FROM orders WHERE order_date < '2023-01-01';",  
        "SELECT * FROM products;",  # 没有WHERE子句  
        "SELECT * FROM products WHERE (price > 100 OR quantity < 10) AND category = 'Electronics';",  
        "SELECT * FROM (SELECT * FROM nested WHERE nested_id = 1) AS subquery WHERE subquery.id = 5;"  # 嵌套查询  
    ]  
    # 遍历示例并打印结果  
    for sql in sql_examples:  
        print(f"Original SQL: {sql}")  
        where_clause = extract_where_clause(sql)  
        print(f"Extracted WHERE Clause: {where_clause}\n")  
# 输出将显示每个SQL语句的原始形式和提取的WHERE子句（如果存在）