Question

我正在使用Python 3.6，pyodbc，并连接到SQL Server。

我正在尝试连接数据库，然后使用参数创建查询。

以下是代码：

import sys
import pyodbc

# connection parameters
nHost = 'host'
nBase = 'base'
nUser = 'user'
nPasw = 'pass'

# make connection start
def sqlconnect(nHost,nBase,nUser,nPasw):
    try:
        return pyodbc.connect('DRIVER={SQL Server};SERVER='+nHost+';DATABASE='+nBase+';UID='+nUser+';PWD='+nPasw)
        print("connection successfull")
    except:
        print ("connection failed check authorization parameters")  
con = sqlconnect(nHost,nBase,nUser,nPasw)
cursor = con.cursor()
# make connection stop

# if run WITHOUT parameters THEN everything is OK   
ask = input ('Go WITHOUT parameters y/n ?')
if ask == 'y':
    # SQL without parameters start
    res = cursor.execute('''
    SELECT * FROM TABLE 
    WHERE TABLE.TIMESTAMP BETWEEN '2017-03-01T00:00:00.000' AND '2017-03-01T01:00:00.000'
    ''')
    # SQL without parameters stop

    # print result to console start
    row = res.fetchone()
    while row:
        print (row)
        row = res.fetchone()
    # print result to console stop

# if run WITH parameters THEN ERROR
ask = input ('Go WITH parameters y/n ?') 
if ask == 'y':

    # parameters start
    STARTDATE = "'2017-03-01T00:00:00.000'"
    ENDDATE = "'2017-03-01T01:00:00.000'"
    # parameters end

    # SQL with parameters start
    res = cursor.execute('''
    SELECT * FROM TABLE 
    WHERE TABLE.TIMESTAMP BETWEEN :STARTDATE AND :ENDDATE
    ''', {"STARTDATE": STARTDATE, "ENDDATE": ENDDATE})
    # SQL with parameters stop

    # print result to console start
    row = res.fetchone()
    while row:
        print (row)
        row = res.fetchone()
    # print result to console stop

当我在SQL中运行没有参数的程序时，它可以工作。

当我尝试使用参数运行时，发生了错误。

Answer 1

通过ODBC的SQL语句中的参数是位置的，并由?标记。因此：

# SQL with parameters start
res = cursor.execute('''
SELECT * FROM TABLE 
WHERE TABLE.TIMESTAMP BETWEEN ? AND ?
''', STARTDATE, ENDDATE)
# SQL with parameters stop

另外，最好避免将日期作为字符串传递。让pyodbc使用Python的datetime来处理它：

from datetime import datetime
...
STARTDATE = datetime(year=2017, month=3, day=1)
ENDDATE = datetime(year=2017, month=3, day=1, hour=0, minute=0, second=1)

然后只传递上述参数。如果您更喜欢字符串解析，请参阅this answer。

Answer 2

我试过并且有很多不同的错误：42000,22007,07002和其他

工作版本如下：

import sys
import pyodbc
import datetime

# connection parameters
nHost = 'host'
nBase = 'DBname'
nUser = 'user'
nPasw = 'pass'

# make connection start
def sqlconnect(nHost,nBase,nUser,nPasw):
    try:
        return pyodbc.connect('DRIVER={SQL Server};SERVER='+nHost+';DATABASE='+nBase+';UID='+nUser+';PWD='+nPasw)
    except:
        print ("connection failed check authorization parameters")  
con = sqlconnect(nHost,nBase,nUser,nPasw)
cursor = con.cursor()
# make connection stop

STARTDATE = '11/2/2017'
ENDDATE = '12/2/2017'
params = (STARTDATE, ENDDATE)

# SQL with parameters start
sql = ('''
SELECT * FROM TABLE 
WHERE TABLE.TIMESTAMP BETWEEN CAST(? as datetime) AND CAST(? as datetime)
''')
# SQL with parameters stop

# print result to console start
query = cursor.execute(sql, params)
row = query.fetchone()
while row:
    print (row)
    row = query.fetchone()
# print result to console stop  
say = input ('everething is ok, you can close console')

Answer 3

我有一个类似的问题。看到使用Python 3.6将PyODBC的版本降级为4.0.6，将SQLAlchemy的版本降为1.2.9可以修复该错误。

Answer 4

如果您尝试像我一样使用pd.to_sql()，则可以通过传递一个名为chunksize的参数来解决此问题。

df.to_sql("tableName", engine ,if_exists='append', chunksize=50)

希望这会有所帮助

pyodbc sql包含0个参数标记，但提供了1个参数''hy000'

4 个答案: