从临时表加载数据到临时表答案

【问题标题】：Loading data to temp table from staging table从临时表加载数据到临时表
【发布时间】：2022-01-22 05:51:17
【问题描述】：

我已将 CSV 文件加载到暂存区。现在我想将此文件转移到临时表。为此，我创建了 3 个不同的模式，即 STG（用于暂存区域）、TMP（用于临时区域）和 TGT（用于目标区域或数据仓库）。这是 STG 架构上的临时表。

GRANT USAGE ON SCHEMA PRASHANT_DWH.STG TO ROLE ACCOUNTADMIN;
CREATE OR REPLACE TABLE PRASHANT_DWH_STG_COUNTRY (
    ID NUMBER(38,0) NOT NULL,
    COUNTRY_DESC VARCHAR(256)
    );

这是 TMP 架构上的临时表。我添加了更多约束，例如维护列和代理键。

GRANT USAGE ON SCHEMA PRASHANT_DWH.TMP TO ROLE ACCOUNTADMIN;
CREATE OR REPLACE TABLE PRASHANT_DWH_TMP_COUNTRY (
    ID NUMBER(38,0) NOT NULL,
    COUNTRY_DESC VARCHAR(256),
    RCD_INS_TS TIMESTAMP, -- aaja ko date
    RCD_UPD_TS TIMESTAMP, -- aaja ko date, if updated then only updated date
    RCD_START_DI DATE, -- system date 
    RCD_CLOSE_DI DATE, -- future date  
    RCD_CLOSE_FLG VARCHAR(1),
    ID_SUR_KEY NUMBER NOT NULL, -- autogenerated, else key + 1, 
    PRIMARY KEY (ID_SUR_KEY) 
    );

我尝试合并这两个表并插入维护列代理键。但它一直显示错误

   MERGE TMP.PRASHANT_DWH_TMP_COUNTRY AS TC
   USING STG.PRASHANT_DWH_STG_COUNTRY AS SC
   ON PDTC.ID = PDSC.ID 
   WHEN MATCHED THEN 
        UPDATE PDTC.ID_SUR_KEY = PDSC.ID + 1 
        INSERT (ID, COUNTRY_DESC,RCD_INS_TS,RCD_UPD_TS,RCD_START_DI,RCD_CLOSE_DI,RCD_CLOSE_FLG,ID_SUR_KEY) 
        VALUES (SC.ID,SC.COUNTRY_DESC,current_timestamp,current_timestamp,current_date,current_date,N,SC.ID + 1)
   WHEN NOT MATCHEN BY TARGET THEN 
        DELETE

给出错误：

SQL compilation error: 
  syntax error line 1 at position 6 unexpected 'TMP'. 
  syntax error line 5 at position 15 unexpected 'PDTC'. 
  syntax error line 6 at position 8 unexpected 'INSERT'. 
  syntax error line 6 at position 32 unexpected ','. 
  syntax error line 6 at position 43 unexpected ','. 
  syntax error line 6 at position 54 unexpected ','. 
  syntax error line 6 at position 67 unexpected ','. 
  syntax error line 6 at position 80 unexpected ','. 
  syntax error line 6 at position 94 unexpected ','. 
  syntax error line 6 at position 105 unexpected ')'. 
  syntax error line 7 at position 37 unexpected ','. 
  syntax error line 7 at position 55 unexpected ','. 
  syntax error line 7 at position 73 unexpected ','. 
  syntax error line 7 at position 86 unexpected ','. 
  syntax error line 7 at position 99 unexpected ','. 
  syntax error line 7 at position 101 unexpected ','. 
  syntax error line 7 at position 108 unexpected '+'. 
  syntax error line 7 at position 111 unexpected ')'.

【问题讨论】：

标签： snowflake-cloud-data-platform etl snowflake-schema

【解决方案1】：

最后的合并缺少一些东西。

MERGE 之后的INTO
我还完全限定了表名（可能不需要）
你使用别名PDTC & PDSC 他们是TC & SC
RCD_CLOSE_FLG中插入的N是一个字符，所以需要用单引号包裹'N'

MERGE INTO PRASHANT_DWH.TMP.PRASHANT_DWH_TMP_COUNTRY AS TC
USING PRASHANT_DWH.STG.PRASHANT_DWH_STG_COUNTRY AS SC
    ON TC.ID = SC.ID 
WHEN MATCHED THEN 
    UPDATE TC.ID_SUR_KEY = SC.ID + 1
    INSERT (ID, COUNTRY_DESC, RCD_INS_TS, RCD_UPD_TS, RCD_START_DI, RCD_CLOSE_DI, RCD_CLOSE_FLG, ID_SUR_KEY) 
    VALUES (SC.ID, SC.COUNTRY_DESC, current_timestamp, current_timestamp, current_date, current_date, 'N', SC.ID + 1)
WHEN NOT MATCHEN BY TARGET THEN DELETE

但是您的MERGE SQL 的尾部有点乱，我不知道如何解决它，因为我不清楚您要做什么。

INSERT 应该绑定到 WHEN MATCHED THEN 或 WHEN NOT MATCHED THEN 而你的WHEN NOT MATCHEN BY TARGET THEN DELETE 似乎..

以太应该是WHEN NOT MATCHEN THEN DELETE，但这似乎会干扰插入。

UPDATE & Insert 最有意义，忽略 DELETE 路径，

MERGE INTO PRASHANT_DWH.TMP.PRASHANT_DWH_TMP_COUNTRY AS TC
USING PRASHANT_DWH.STG.PRASHANT_DWH_STG_COUNTRY AS SC
    ON TC.ID = SC.ID 
WHEN MATCHED THEN 
    UPDATE TC.ID_SUR_KEY = SC.ID + 1
WHEN NOT MATCHED THEN
    INSERT (ID, COUNTRY_DESC, RCD_INS_TS, RCD_UPD_TS, 
        RCD_START_DI, RCD_CLOSE_DI, RCD_CLOSE_FLG, ID_SUR_KEY) 
    VALUES (SC.ID, SC.COUNTRY_DESC, current_timestamp, 
        current_timestamp, current_date, current_date, 'N', 
        SC.ID + 1);

【讨论】：