UpdateItem Dynamodb Boto3 说查询错误

问题描述

我正在尝试增加特定列的值。 我正在使用 Boto3。

update_query = '#clicks.#OS.#os = #clicks.#OS.#os + :inc,#clicks.#Brands.#brand = #clicks.#Brands.#brand + :inc,#clicks.#RAMs.#ram = #clicks.#RAMs.#ram + :inc'
table_urls.update_item(
            Key={
                'urlid': urlid
            },UpdateExpression=update_query,ExpressionAttributeValues={
                ':inc' : Decimal(1)
            },ExpressionAttributeNames={
                "#os"   : os,"#brand": brand,"#ram"  : ram,"#clicks": "clicks","#OS"   : "OS","#Brands": "Brands","#RAMs"  : "RAMs"
            },ReturnValues='NONE'
        )

这是错误堆栈跟踪： 错误：

An error occurred (ValidationException) when calling the UpdateItem operation: Invalid UpdateExpression: Syntax error; token: "#clicks",near: "#clicks."
QUERY::>> #clicks.#OS.#os = #clicks.#OS.#os + :inc,#clicks.#RAMs.#ram = #clicks.#RAMs.#ram + :inc

解决方法

尝试在 update_query 字符串的开头添加 SET。一切休息似乎都很正常。

update_query = 'SET #clicks.#OS.#os = #clicks.#OS.#os + :inc,#clicks.#Brands.#brand = #clicks.#Brands.#brand + :inc,#clicks.#RAMs.#ram = #clicks.#RAMs.#ram + :inc'
table_urls.update_item(
            Key={
                'urlid': urlid
            },UpdateExpression=update_query,ExpressionAttributeValues={
                ':inc' : Decimal(1)
            },ExpressionAttributeNames={
                "#os"   : os,"#brand": brand,"#ram"  : ram,"#clicks": "clicks","#OS"   : "OS","#Brands": "Brands","#RAMs"  : "RAMs"
            },ReturnValues='NONE'
        )