MariaDB，pypyodbc，"Unknown prepared statement handler" 在加载 "LOAD DATA LOCAL INFILE." 的 table 上执行 "SELECT" 查询

Question

Python 3.4.3，MariaDB 10.0.21，MariaDB ODBC 连接器 1.0.0，pypyodbc 1.3.3，64 位上的所有 64 位 Windows 7.

我有一个 python 脚本，它应该创建一个 table，用固定宽度文件中的数据填充它，然后运行一个 SELECT 声明反对。所有简单的东西。我的脚本看起来像这样：

import pypyodbc

def do_stuff(name, password, filepath):
    db = pypyodbc.connect(driver = "{MariaDB ODBC 1.0 Driver}",
                    server = "localhost", uid = name,
                    pwd = password, autocommit = True)

    cursor = db.cursor()

    cursor.execute("CREATE TABLE `foo`.`bar` (`col1` INT);")
    cursor.execute("LOAD DATA LOCAL INFILE '%s' INTO TABLE `foo`.`bar` (@row) SET col1 = SUBSTR(@row,1,1)" % filepath.replace("\", "\\"))
    for row in cursor.execute("SELECT * FROM `foo`.`bar`"):
        print(row)
    db.close()

do_stuff("root", "password", r"C:\Users\laj\Desktop\test.txt")

它从文本文件的每一行中抓取第一个字符并将其粘贴在 table 的唯一列中。然而，当 "SELECT" 语句出现时，我遇到了以下错误：

Traceback (most recent call last):
  File "test.py", line 25, in <module>
    do_stuff("root", "oag123", r"C:\Users\laj\Desktop\test.txt")
  File "test.py", line 21, in do_stuff
    for row in cursor.execute("SELECT * FROM `foo`.`bar`"):
  File "C:\Python34\lib\site-packages\pypyodbc-1.3.3-py3.4.egg\pypyodbc.py", line 1605, in execute
  File "C:\Python34\lib\site-packages\pypyodbc-1.3.3-py3.4.egg\pypyodbc.py", line 1631, in execdirect
  File "C:\Python34\lib\site-packages\pypyodbc-1.3.3-py3.4.egg\pypyodbc.py", line 986, in check_success
  File "C:\Python34\lib\site-packages\pypyodbc-1.3.3-py3.4.egg\pypyodbc.py", line 964, in ctrl_err
pypyodbc.Error: ('HY000', '[HY000] Unknown prepared statement handler (5) given to mysqld_stmt_reset')

真正让我着迷的是，我可以通过在填充 table 和执行 "SELECT," 之间关闭并重新打开数据库连接来摆脱错误，如下所示：

import pypyodbc

def do_stuff(name, password, filepath):
    db = pypyodbc.connect(driver = "{MariaDB ODBC 1.0 Driver}",
                    server = "localhost", uid = name,
                    pwd = password, autocommit = True)

    cursor = db.cursor()

    cursor.execute("CREATE TABLE `foo`.`bar` (`col1` INT);")
    cursor.execute("LOAD DATA LOCAL INFILE '%s' INTO TABLE `foo`.`bar` (@row) SET col1 = SUBSTR(@row,1,1)" % filepath.replace("\", "\\"))

    db.close()
    db = pypyodbc.connect(driver = "{MariaDB ODBC 1.0 Driver}",
                    server = "localhost", uid = name,
                    pwd = password, autocommit = True)

    cursor = db.cursor()


    for row in cursor.execute("SELECT * FROM `foo`.`bar`"):
        print(row)
    db.close()

do_stuff("root", "password", r"C:\Users\laj\Desktop\test.txt")

不幸的是，这实际上不是解决我的问题的有效方法。这不仅是我不应该做的事情，而且在涉及临时 table 时也无济于事，因为它们只是在 "fix." 的断开连接阶段被丢弃任何见解都会太棒了，这让我很难过。

Answer 1

execute并不return你想的那样：

cursor.execute("SELECT ...");
rows = cur.fetchall();
for row in rows ...

Answer 2

原来是pypyodbc的问题。安装了 pyodbc，将其导入为 pypyodbc，一切正常。

MariaDB，pypyodbc，"Unknown prepared statement handler" 在加载 "LOAD DATA LOCAL INFILE." 的 table 上执行 "SELECT" 查询

MariaDB, pypyodbc, "Unknown prepared statement handler" executing "SELECT" query on table loaded with "LOAD DATA LOCAL INFILE."

odbc

windows-7-x64

mariadb

python-3.x

pypyodbc