我在Python 2.7中使用PyMySQL。我必须创建一个函数-给定一个表名,查询将在其中找到所有列名的唯一值。
由于涉及多个表,因此我不想对表名进行硬编码。现在,一个更简单的查询如下:
cursor.execute(" SELECT DISTINCT(`Trend`) AS `Trend` FROM `Table_1` ORDER BY `Trend` DESC ")
我想做类似的事情:
tab = 'Table_1'
cursor.execute(" SELECT DISTINCT(`Trend`) AS `Trend` FROM tab ORDER BY `Trend` DESC ")
我收到以下错误:
ProgrammingError: (1146, u"Table 'Table_1.tab' doesn't exist")
有人可以帮忙吗? TIA
最佳答案
确保您使用的数据库正确,并使用%s
格式化sql语句。
DB_SCHEMA='test_db'
table_name='table1'
connection = pymysql.connect(host=DB_SERVER_IP,
port=3306,
db=DB_SCHEMA,
charset='UTF8',
cursorclass=pymysql.cursors.DictCursor
)
try:
with connection.cursor() as cursor:
sql = "SELECT DISTINCT(`Trend`) AS `Trend` FROM `%s` ORDER BY `Trend` DESC"%(table_name)
cursor.execute(sql)
connection.commit()
except Exception as e:
print e
finally:
connection.close()
希望这可以帮助。