脚本不执行 cur.execute() 中的命令

Question

我是 PostgreSQL 和 psycopg2 的新手，我遇到了一个问题。

import psycopg2


def create_tables(whichone):

     in_str_station = "CREATE TABLE station (id SMALLINT NOT NULL PRIMARY KEY,  name VARCHAR(40) NOT NULL," \
                 " country VARCHAR(3) NOT NULL, latitude VARCHAR(10),  " \
                 "longitude VARCHAR(10),height SMALLINT);"

     in_str_dailyData = "CREATE TABLE daily_data (id BIGSERIAL NOT NULL PRIMARY KEY," \
                   "s_id SMALLINT NOT NULL REFERENCES station(id)," \
                   "d_date DATE NOT NULL, d_mean NUMERIC(6, 1), quality SMALLINT);"

     int_str_monthlyMean = "CREATE TABLE monthly_mean (id BIGSERIAL NOT NULL PRIMARY KEY,"\
                      "s_id SMALLINT NOT NULL REFERENCES station(id),"\
                      "m_date DATE NOT NULL, m_mean NUMERIC(9, 3),"\
                      "var NUMERIC(9, 3), std NUMERIC(9, 3));"

     in_str_yearlymean = "CREATE TABLE yearly_mean (id BIGSERIAL NOT NULL PRIMARY KEY, " \
                    "s_id SMALLINT NOT NULL REFERENCES station(id)," \
                    "y_date DATE NOT NULL, y_mean NUMERIC(9, 3),var NUMERIC(9, 3)," \
                    "std NUMERIC(9, 3), var_m NUMERIC(9, 3), std_m NUMERIC(9, 3));"

     database_list = {'station': in_str_station, 'monthly_mean': int_str_monthlyMean,
                 'daily_data': in_str_dailyData, 'yearly_mean': in_str_yearlymean}

     try:
        conn = psycopg2.connect(
          host="localhost",
          database="climate",
          user="postgres",
          password="1")

       cur = conn.cursor()
       in_str = database_list.get(whichone)
       cur.execute(in_str)
       output_ = cur.fetchall()
       print(output_)
       cur.close()
    except (Exception, psycopg2.DatabaseError) as error:
       print(error)
    finally:
       if conn is not None:
          conn.close()

在我运行脚本之后，无论我选择 in_str_ 中的哪一个，都不会创建 table。我已经检查过，当我复制在 cur.execute 中执行的 in_str 的内容并在 PostgreSQL 中使用它时shell，一切正常。

我哪里错了？

Answer 1

我不知道你是不是在这里做的，但缩进错了。您需要在函数后缩进代码。

def foo(a):
    pass

Answer 2

在 cur.execute() 之后 conn.close() 之前调用 conn.commit()。与 psycopg2 的交易 are not implicitly committed：

If the connection is closed (using the close() method) or destroyed (using del or by letting it fall out of scope) while a transaction is in progress, the server will discard the transaction.

脚本不执行 cur.execute() 中的命令

A script doesn't execute the command in cur.execute()

python

sql

postgresql

psycopg2