mysql判断是否存在数据库

SHOW DATABASES LIKE 'your_database_name';

SELECT SCHEMA_NAME FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME = 'your_database_name';

SELECT COUNT(*) FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME = 'your_database_name';

import mysql.connector

def database_exists(host, user, password, database_name):
    try:
        conn = mysql.connector.connect(host=host, user=user, password=password)
        cursor = conn.cursor()
        cursor.execute("SHOW DATABASES LIKE %s", (database_name,))
        result = cursor.fetchone()
        return result is not None
    except mysql.connector.Error as err:
        print(f"Error: {err}")
        return False
    finally:
        if conn.is_connected():
            cursor.close()
            conn.close()

# 使用示例
host = 'localhost'
user = 'your_username'
password = 'your_password'
database_name = 'your_database_name'

if database_exists(host, user, password, database_name):
    print(f"The database '{database_name}' exists.")
else:
    print(f"The database '{database_name}' does not exist.")