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我正在尝试从 Firebird 数据库中的表中获取数据。到目前为止，我已经成功地建立了连接并获得了表名。在此处的其他一些帖子之后，我已经设法使用光标函数“选择”（无论这意味着什么）我想要读取的数据库，但我无法检索信息并在 Pandas 中使用它，即我想要的是。

这是我的代码，我希望你能帮助我解决这个问题：

#Connection is made
con=fdb.connect(dsn=r'C:\table.FDB',user='SYSD', password='key')

#I don't know what this is for, but it helps me get the table names and somehow I think I'm getting closer.

schema1=fdb.schema.Schema()
schema1.bind(con)
for i in range(len(schema1.tables)):
    print(schema1.tables[i].name)
    
#This I got it from this post that said it would retrieve the data, but I just don't know how to get it: https://stackoverflow.com/questions/64826318/extract-data-from-a-firebird-database-with-python-fdb-module 

cur1=con.cursor()
cur1.execute('select * from "INVE04"')

#I get the following:
<fdb.fbcore.Cursor at 0x2b213a0fe20>

接下来我应该怎么做才能读取数据？我不熟悉 Firebird，所以查阅文档我找不到任何方法或方式来读取/提取/使用每个表中的数据。我在这里走对了吗？

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1 回答 1

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Firebird FDB 驱动程序实现了Python DB API 2.0 (PEP-249)。您检索行的方式已在此 API 中标准化，也记录在FDB 文档中。具体来说，执行 SQL 语句显示了处理查询结果的 3 种不同方式：

import fdb

con = fdb.connect(dsn='/temp/test.db', user='sysdba', password='masterkey')

cur = con.cursor()
SELECT = "select name, year_released from languages order by year_released"

# 1. Using built-in support for iteration protocol to iterate over the rows available from the cursor,
# unpacking the resulting sequences to yield their elements (name, year_released):
cur.execute(SELECT)
for (name, year_released) in cur:
    print '%s has been publicly available since %d.' % (name, year_released)
# or alternatively you can take an advantage of cur.execute returning self.
for (name, year_released) in cur.execute(SELECT):
    print '%s has been publicly available since %d.' % (name, year_released)

# 2. Equivalently using fetchall():
# This is potentially dangerous if result set is huge, as the whole result set is first materialized
# as list and then used for iteration.
cur.execute(SELECT)
for row in cur.fetchall():
    print '%s has been publicly available since %d.' % (row[0], row[1])

# 3. Using mapping-iteration rather than sequence-iteration:
cur.execute(SELECT)
for row in cur.itermap():
    print '%(name)s has been publicly available since %(year_released)d.' % row

简而言之，您可以迭代游标本身（序列迭代，选项 1），您可以使用fetchall()（选项 2）将所有行提取到列表中，或者您可以使用itermap()（映射迭代，选项 3）。

还有其他选项（例如重复调用fetchone()，或使用 批量获取fetchmany()）。

于 2021-06-04T09:25:11.403 回答