问题
I am trying to execute SQL query within Access database using PYODBC and I get following error:
pyodbc.Error: ('07002', '[07002] [Microsoft][ODBC Microsoft Access Driver] Too few parameters. Expected 1. (-3010) (SQLExecDirectW)')
The problem is that I am not using any additional parameters. Here is the code:
access_con_string = r"Driver={};Dbq={};".format(driver, base)
cnn = pyodbc.connect(access_con_string)
db_cursor = cnn.cursor()
expression = """SELECT F_ARODES.ARODES_INT_NUM, F_ARODES.TEMP_ADRESS_FOREST,F_AROD_LAND_USE.ARODES_INT_NUM, F_ARODES.ARODES_TYP_CD
FROM F_ARODES LEFT JOIN F_AROD_LAND_USE ON F_ARODES.ARODES_INT_NUM = F_AROD_LAND_USE.ARODES_INT_NUM
WHERE (((F_AROD_LAND_USE.ARODES_INT_NUM) Is Null) AND ((F_ARODES.ARODES_TYP_CD)="wydziel") AND ((F_ARODES.TEMP_ACT_ADRESS)=True));"""
db_cursor.execute(expression)
Query itself, if used inside MS-Access works fine. Also, connection is OK, as other queries are executed properly. What am I doing wrong?
回答1:
Constants in such queries are problematic - you never know the exact underlying syntax for booleans, strings etc. - even if it works in MS-Access, it can be different inside the intermediary library you're using.
The safest way is to extract them as parameters anyway:
expression = """SELECT F_ARODES.ARODES_INT_NUM, F_ARODES.TEMP_ADRESS_FOREST,F_AROD_LAND_USE.ARODES_INT_NUM, F_ARODES.ARODES_TYP_CD FROM F_ARODES LEFT JOIN F_AROD_LAND_USE ON F_ARODES.ARODES_INT_NUM = F_AROD_LAND_USE.ARODES_INT_NUM WHERE (((F_AROD_LAND_USE.ARODES_INT_NUM) Is Null)
AND ((F_ARODES.ARODES_TYP_CD)=?) AND ((F_ARODES.TEMP_ACT_ADRESS)=?));"""
db_cursor.execute(expression, "wydziel", True)
回答2:
I had a similar problem, with an update I was trying to perform with pyodbc. When executed in Access, the query worked fine, same for when using the application (it allows some queries from within the app). But when ran in python with pyodbc the same text would throw errors. I determined the problem is the double quote (OP's query has a set of them as well). The query began to work when I replaced them with single quotes.
This does not work:
Update ApplicationStandards Set ShortCutKey = "I" Where ShortName = "ISO"
This does:
Update ApplicationStandards Set ShortCutKey = 'I' Where ShortName = 'ISO'
来源：https://stackoverflow.com/questions/42834490/too-few-parameters-error-while-no-parameters-placeholders-used