Question

我目前正在编写一个脚本来使用Python运行多个SQL文件，在你提到替代方法之前有一点背景;这是自动化脚本，Python是我在Windows 2008服务器上使用的唯一工具。我有一个适用于一组的脚本，但问题是当另一个集合有两个语句而不是一个由一个＆＃39 ;;＃39;这是我的代码：

╔══════════╦═══════╦════════════╗
║ MasterID ║ SubID ║  Location  ║
╠══════════╬═══════╬════════════╣
║       99 ║    29 ║ California ║
║       99 ║    28 ║ Texas      ║
║       99 ║    28 ║ California ║
║       97 ║     5 ║ California ║
╚══════════╩═══════╩════════════╝

因此，此代码可以显示整个文件，但它只会在＆＃34;;＆＃34;之前执行一个语句。

任何帮助都会很棒！

感谢。

Answer 1

pyodbc连接器（或pymysql）中的API不允许SQL调用中的多个语句。这是引擎解析的问题; API需要完全理解它传递的SQL才能传递多个语句，然后在返回时处理多个结果。

对您的脚本进行略微修改，如下所示，您可以使用单独的连接器单独发送每个语句：

import os
import pyodbc

print ("Connecting via ODBC")

conn = pyodbc.connect('DSN=dsn', autocommit=True)

print ("Connected!\n")

inputdir = 'C:\\path'

for script in os.listdir(inputdir):
    with open(inputdir+'\\' + script,'r') as inserts:
        sqlScript = inserts.readlines()
        for statement in sqlScript.split(';'):
            with conn.cursor() as cur:
                cur.execute(statement)
    print(script)

conn.close()

with conn.cursor() as cur:打开一个关闭每个语句的游标，在每个调用完成后正确退出。

Answer 2

更正确的方法是解析注释和引用的字符串，并且只考虑它们之外的;。否则，在您使用块注释注释掉多个SQL语句后，您的代码将立即被破坏。

这是我为自己制作的基于状态机的实现 - 这段代码可能很难看，写得好多了，所以请随意改进它。它没有处理MySQL风格的# - 开始评论，但很容易添加。

def split_sql_expressions(text):
    results = []
    current = ''
    state = None
    for c in text:
        if state is None:  # default state, outside of special entity
            current += c
            if c in '"\'':
                # quoted string
                state = c
            elif c == '-':
                # probably "--" comment
                state = '-'
            elif c == '/':
                # probably '/*' comment
                state = '/'
            elif c == ';':
                # remove it from the statement
                current = current[:-1].strip()
                # and save current stmt unless empty
                if current:
                    results.append(current)
                current = ''
        elif state == '-':
            if c != '-':
                # not a comment
                state = None
                current += c
                continue
            # remove first minus
            current = current[:-1]
            # comment until end of line
            state = '--'
        elif state == '--':
            if c == '\n':
                # end of comment
                # and we do include this newline
                current += c
                state = None
            # else just ignore
        elif state == '/':
            if c != '*':
                state = None
                current += c
                continue
            # remove starting slash
            current = current[:-1]
            # multiline comment
            state = '/*'
        elif state == '/*':
            if c == '*':
                # probably end of comment
                state = '/**'
        elif state == '/**':
            if c == '/':
                state = None
            else:
                # not an end
                state = '/*'
        elif state[0] in '"\'':
            current += c
            if state.endswith('\\'):
                # prev was backslash, don't check for ender
                # just revert to regular state
                state = state[0]
                continue
            elif c == '\\':
                # don't check next char
                state += '\\'
                continue
            elif c == state[0]:
                # end of quoted string
                state = None
        else:
            raise Exception('Illegal state %s' % state)

    if current:
        current = current.rstrip(';').strip()
        if current:
            results.append(current)

return results

并像这样使用它：

with open('myfile.sql', 'r') as sqlfile:
    for stmt in split_sql_expressions(sqlfile.read()):
        cursor.execute(stmt)

执行带有多个语句的SQL文件，用＆＃34;;＆＃34;分隔。使用pyodbc

2 个答案: