问题
i have the following function which extracts data from table, but i want to pass the table name in function as parameter...
def extract_data(table):
try:
tableName = table
conn_string = "host='localhost' dbname='Aspentiment' user='postgres' password='pwd'"
conn=psycopg2.connect(conn_string)
cursor = conn.cursor()
cursor.execute("SELECT aspects_name, sentiments FROM ('%s') " %(tableName))
rows = cursor.fetchall()
return rows
finally:
if conn:
conn.close()
when i call function as extract_data(Harpar) : Harpar is table name but it give an error that 'Harpar' is not defined.. any hepl ?
回答1:
Update: As of psycopg2 version 2.7:
You can now use the sql module of psycopg2 to compose dynamic queries of this type:
from psycopg2 import sql
query = sql.SQL("SELECT aspects_name, sentiments FROM {}").format(sql.Identifier(tableName))
cursor.execute(query)
Pre < 2.7:
Use the AsIs adapter along these lines:
from psycopg2.extensions import AsIs
cursor.execute("SELECT aspects_name, sentiments FROM %s;",(AsIs(tableName),))
Without the AsIs adapter, psycopg2 will escape the table name in your query.
来源:https://stackoverflow.com/questions/35347625/how-to-use-passed-parameter-as-table-name-in-select-query-python