您可以像这样使用内部连接从另一个表更新值

UPDATE [table1_name] AS t1 INNER JOIN [table2_name] AS t2 ON t1.column1_name] = t2.[column1_name] SET t1.[column2_name] = t2.column2_name];

跟随这里了解如何使用这个查询http://www.voidtricks.com/mysql-inner-join-update/

或者您可以使用select作为子查询来完成此操作

UPDATE [table_name] SET [column_name] = (SELECT [column_name] FROM [table_name] WHERE [column_name] = [value]) WHERE [column_name] = [value];

查询详情请参见http://www.voidtricks.com/mysql-update-from-select/

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。

我有一个重复的条目在一个表本身的问题。以下是对我有效的方法。@sibaz也提倡这样做。

最后我用下面的查询解决了这个问题:

The select query is saved in a temp table IF OBJECT_ID(N'tempdb..#New_format_donor_temp', N'U') IS NOT NULL DROP TABLE #New_format_donor_temp; select * into #New_format_donor_temp from DONOR_EMPLOYMENTS where DONOR_ID IN ( 1, 2 ) -- Test New_format_donor_temp -- SELECT * -- FROM #New_format_donor_temp; The temp table is joined in the update query. UPDATE de SET STATUS_CD=de_new.STATUS_CD, STATUS_REASON_CD=de_new.STATUS_REASON_CD, TYPE_CD=de_new.TYPE_CD FROM DONOR_EMPLOYMENTS AS de INNER JOIN #New_format_donor_temp AS de_new ON de_new.EMP_NO = de.EMP_NO WHERE de.DONOR_ID IN ( 3, 4 )

我不是很有经验的SQL请建议任何更好的方法你知道。

以上查询是针对MySql服务器的。

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];

我在寻找一个非常复杂的连接的解决方案时发现了这个问题。这是另一种解决方案，一个更复杂的问题，我认为可能有用。

我需要填充活动表中的product_id字段，其中活动以单位编号，单位以级别编号(使用字符串??N标识)，这样就可以使用SKU(即L1U1A1)标识活动。然后将这些sku存储在另一个表中。

我确定了以下内容以获得activity_id与product_id的列表:-

SELECT a.activity_id, w.product_id 
  FROM activities a 
  JOIN units USING(unit_id) 
  JOIN product_types USING(product_type_id) 
  JOIN web_products w 
    ON sku=CONCAT('L',SUBSTR(product_type_code,3), 'U',unit_index, 'A',activity_index)

我发现这是太复杂，以纳入一个SELECT在mysql，所以我创建了一个临时表，并加入了更新语句:-

CREATE TEMPORARY TABLE activity_product_ids AS (<the above select statement>);

UPDATE activities a
  JOIN activity_product_ids b
    ON a.activity_id=b.activity_id 
  SET a.product_id=b.product_id;

我希望有人觉得这有用

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);