我需要检查(从同一个表中)两个事件之间是否存在基于日期-时间的关联。

一组数据将包含某些事件的结束日期-时间,另一组数据将包含其他事件的开始日期-时间。

如果第一个事件在第二个事件之前完成,那么我想把它们联系起来。

到目前为止,我有:

SELECT name as name_A, date-time as end_DTS, id as id_A 
FROM tableA WHERE criteria = 1


SELECT name as name_B, date-time as start_DTS, id as id_B 
FROM tableA WHERE criteria = 2

然后我加入他们:

SELECT name_A, name_B, id_A, id_B, 
if(start_DTS > end_DTS,'VALID','') as validation_check
FROM tableA
LEFT JOIN tableB ON name_A = name_B

然后,我可以根据validation_check字段运行一个带有SELECT嵌套的UPDATE查询吗?


当前回答

如果您正在从一个复杂的查询进行更新。最好的方法是从查询创建临时表,然后使用临时表作为一个查询进行更新。

    DROP TABLE IF EXISTS cash_sales_sums;
CREATE TEMPORARY TABLE cash_sales_sums as
SELECT tbl_cash_sales_documents.batch_key, COUNT(DISTINCT tbl_cash_sales_documents.cash_sale_number) no_of_docs,
  SUM(tbl_cash_sales_documents.paid_amount) paid_amount, SUM(A.amount - tbl_cash_sales_documents.bonus_amount - tbl_cash_sales_documents.discount_given) amount,
  SUM(A.recs) no_of_entries FROM 
        tbl_cash_sales_documents
    RIGHT JOIN(
        SELECT
            SUM(
                tbl_cash_sales_transactions.amount
            )amount,
            tbl_cash_sales_transactions.cash_sale_document_id,
            COUNT(transaction_id)recs
        FROM
            tbl_cash_sales_transactions
        GROUP BY
            tbl_cash_sales_transactions.cash_sale_document_id
    )A ON A.cash_sale_document_id = tbl_cash_sales_documents.cash_sale_id
    GROUP BY
        tbl_cash_sales_documents.batch_key
ORDER BY batch_key;





UPDATE tbl_cash_sales_batches SET control_totals = (SELECT amount FROM cash_sales_sums WHERE cash_sales_sums.batch_key = tbl_cash_sales_batches.batch_key LIMIT 1),
expected_number_of_documents = (SELECT no_of_docs FROM cash_sales_sums WHERE cash_sales_sums.batch_key = tbl_cash_sales_batches.batch_key),
computer_number_of_documents = expected_number_of_documents,  computer_total_amount = control_totals
WHERE batch_key IN (SELECT batch_key FROM cash_sales_sums);

其他回答

实际上你有两种方法:

MySQL更新连接语法:

UPDATE tableA a
INNER JOIN tableB b ON a.name_a = b.name_b
SET validation_check = if(start_dts > end_dts, 'VALID', '')
-- where clause can go here

ANSI SQL语法:

UPDATE tableA SET validation_check = 
    (SELECT if(start_DTS > end_DTS, 'VALID', '') AS validation_check
        FROM tableA
        INNER JOIN tableB ON name_A = name_B
        WHERE id_A = tableA.id_A)

挑一个对你来说最自然的。

UPDATE [table_name] AS T1,
      (SELECT [column_name] 
        FROM [table_name] 
        WHERE [column_name] = [value]) AS T2 
  SET T1.[column_name]=T2.[column_name] + 1
WHERE T1.[column_name] = [value];
UPDATE 
  receipt_invoices dest,
  (
    SELECT 
      `receipt_id`,
      CAST((net * 100) / 112 AS DECIMAL (11, 2)) witoutvat 
    FROM
      receipt 
    WHERE CAST((net * 100) / 112 AS DECIMAL (11, 2)) != total 
      AND vat_percentage = 12
  ) src 
SET
  dest.price = src.witoutvat,
  dest.amount = src.witoutvat 
WHERE col_tobefixed = 1 
  AND dest.`receipt_id` = src.receipt_id ;

希望这将帮助你在一个情况下,你必须匹配和更新两个表。

简单的MySQL:

UPDATE users AS U1, users AS U2 
SET U1.name_one = U2.name_colX
WHERE U2.user_id = U1.user_id

如果您正在从一个复杂的查询进行更新。最好的方法是从查询创建临时表,然后使用临时表作为一个查询进行更新。

    DROP TABLE IF EXISTS cash_sales_sums;
CREATE TEMPORARY TABLE cash_sales_sums as
SELECT tbl_cash_sales_documents.batch_key, COUNT(DISTINCT tbl_cash_sales_documents.cash_sale_number) no_of_docs,
  SUM(tbl_cash_sales_documents.paid_amount) paid_amount, SUM(A.amount - tbl_cash_sales_documents.bonus_amount - tbl_cash_sales_documents.discount_given) amount,
  SUM(A.recs) no_of_entries FROM 
        tbl_cash_sales_documents
    RIGHT JOIN(
        SELECT
            SUM(
                tbl_cash_sales_transactions.amount
            )amount,
            tbl_cash_sales_transactions.cash_sale_document_id,
            COUNT(transaction_id)recs
        FROM
            tbl_cash_sales_transactions
        GROUP BY
            tbl_cash_sales_transactions.cash_sale_document_id
    )A ON A.cash_sale_document_id = tbl_cash_sales_documents.cash_sale_id
    GROUP BY
        tbl_cash_sales_documents.batch_key
ORDER BY batch_key;





UPDATE tbl_cash_sales_batches SET control_totals = (SELECT amount FROM cash_sales_sums WHERE cash_sales_sums.batch_key = tbl_cash_sales_batches.batch_key LIMIT 1),
expected_number_of_documents = (SELECT no_of_docs FROM cash_sales_sums WHERE cash_sales_sums.batch_key = tbl_cash_sales_batches.batch_key),
computer_number_of_documents = expected_number_of_documents,  computer_total_amount = control_totals
WHERE batch_key IN (SELECT batch_key FROM cash_sales_sums);