正确的列名的选择

#standardSQL 
SELECT 
    blockchain.num_tx AS `num_tx`, 
    blockchain.timestamp AS `timestamp`, 
    GDELT.GLOBALEVENTID AS GLOBALEVENTID, 
    PARSE_TIMESTAMP('%Y%m%d', CAST(GDELT.SQLDATE AS STRING)) AS SQLDATE, 
    GDELT.Actor1Code AS Actor1Code, 
    GDELT.Actor1Name AS Actor1Name, 
    GDELT.Actor2Code AS Actor2Code, 
    GDELT.Actor2Name AS Actor2Name, 
    GDELT.AvgTone AS AvgTone, 
    GDELT.SOURCEURL AS SOURCEURL 
FROM 
    w205_final_project.blockchain_data AS blockchain 
INNER JOIN 
    w205_final_project.GDELT AS GDELT 
ON 
    blockchain.timestamp = GDELT.SQLDATE

返回以下：正确的列名的选择

Error: No matching signature for operator = for argument types: TIMESTAMP, INT64. Supported signature: ANY = ANY at [18:3]

GDELT.SQLDATE列数据是，首先，作为YYYYMMDD整数格式; blockchain.timestamp列是timestamp格式开始，例如：

2015-01-01 04:29:21 UTC

来源

2017-04-14 Frederic Bastiat

什么是SQLDate的类型？你想用它做什么？ –

SQLDATE最初是一个整数。该线路正常工作; sqldate被转换为字符串，然后根据需要转换为时间戳。这是blockchain.timestamp行，给我带来麻烦。我想结束这两个时间戳格式化的列（名为时间戳的列确实已经是时间戳格式）。 –

显示错误信息！并显示'GDELT.SQLDATE'和'blockchain.timestamp'的几个例子 - 下面的链接可以帮助你 - 如何显示[最小，完整和可验证的例子]（http://stackoverflow.com/help/mcve）代码，你有问题和[如何问]（http://stackoverflow.com/help/how-to-ask）。 –

我不是一个专家的BigQuery，但SQLDAT(_PARSED)只有经过此查询的连接产生的场，你会找不到它在join条款SQLDATE(_PARSED)

你应该切换您GDELT.SQLDATE到PARSE_TIMESTAMP('%Y%m%d', CAST(GDELT.SQLDATE AS STRING))

#standardSQL 
SELECT 
    blockchain.num_tx AS `num_tx`, 
    blockchain.timestamp AS `timestamp`, 
    GDELT.GLOBALEVENTID AS GLOBALEVENTID, 
    PARSE_TIMESTAMP('%Y%m%d', CAST(SQLDATE AS STRING)) AS SQLDATE, 
    GDELT.Actor1Code AS Actor1Code, 
    GDELT.Actor1Name AS Actor1Name, 
    GDELT.Actor2Code AS Actor2Code, 
    GDELT.Actor2Name AS Actor2Name, 
    GDELT.AvgTone AS AvgTone, 
    GDELT.SOURCEURL AS SOURCEURL 
FROM 
    final_project.blockchain_data AS blockchain 
INNER JOIN 
    final_project.GDELT AS GDELT 
ON 
    blockchain.timestamp = PARSE_TIMESTAMP('%Y%m%d', CAST(GDELT.SQLDATE AS STRING))

二点，别列命名timestamp，这是一个SQL关键字，它的保留，同去time，date，......至少，尝试你的别名重命名为类似blockchain.timestamp AS created`

并避免命名您的别名比你的列相同：

SELECT PARSE_TIMESTAMP('%Y%m%d', CAST(GDELT.SQLDATE AS STRING)) AS SQLDATE, 
FROM blockchain_data AS blockchain 
INNER JOIN GDELT 
    ON blockchain.timestamp = GDELT.SQLDATE;

是不一样的：

SELECT PARSE_TIMESTAMP('%Y%m%d', CAST(SQLDATE AS STRING)) AS SQLDATE_PARSED, 
FROM blockchain_data AS blockchain 
INNER JOIN GDELT 
    -- not what you want, but what you do, with error TIMESTAMP = INT64 
    ON blockchain.timestamp = SQLDATE 
    -- what you want, but show ERROR column not fould 
    ON blockchain.timestamp = SQLDATE_PARSED 
    -- Is the valid expression 
    ON blockchain.timestamp = PARSE_TIMESTAMP('%Y%m%d', CAST(SQLDATE AS STRING))

来源

2017-04-14 01:26:39 Blag

正确的列名的选择

回答

相关问题