UPDATE is efficient because it allows multiple columns to be updated using a single statement. The following is the syntax of the UPDATE statement. -- Update specific columns in a table UPDATE table_name SET column1 = value1, column2 = value2, column3 = value3 WHERE condition; Powered By...
With a syntax shortcut for updating multiple columns - shorter than what other answers suggested so far in any case. UPDATE b SET ( column1, column2, column3) = (a.column1, a.column2, a.column3) FROM a WHERE b.id = 123 -- optional, to update only selected row AND a.id = b....
Example: SQL UPDATE Statement Update Multiple Values in a Row We can also update multiple values in a single row at once. For example, -- update multiple values in the given rowUPDATECustomersSETfirst_name ='Johnny', last_name ='Depp'WHEREcustomer_id =1; Run Code Here, the SQL command ...
因此在DML触发器中,COLUMNS_UPDATED函数是一个非常重要且有用的函数。 不同于UPDATE函数,COLUMNS_UPDATED函数可以工作在多个列中,它使用字节中的位(Bit)标识列是否已被修改(也就是采用二进制的方式),而不是在参数中传递列名。我们都知道,1字节(BYTE)=8比特(Bit),因此仅仅使用COLUMNS_UPDATED函数,则只能够标识一个...
Multiple-tablesyntax:#多表修改语句结构UPDATE[LOW_PRIORITY][IGNORE]table_referencesSETassignment_list[WHERE where_condition]Forthesingle-tablesyntax, theUPDATEstatement updates columnsofexisting rowsinthe namedtablewithnewvalues. TheSETclause indicates which columnstomodifyandthevaluesthey should be given. ...
set @npos=charindex(',',@Columns,@cpos); set @sql = 'update '+@Table+' set '+@Column+'=replace(cast('+@Column+' as varchar(8000)),@old,@new) where Datalength('+@Column+')<=8000'; EXECUTE sp_executesql @Sql, N'@old varchar(100),@new varchar(100)', ...
报错:Update row with Key (id)=(xxxx) multiple times或者duplicate key value violates unique constraint 问题原因:违反唯一性约束,执行UPDATE、INSERT ON CONFLICT或INSERT操作时,主键存在重复数据。 解决方法: 若INSERT语法报错:可以改为INSERT INTO xx ON CONFLICT的语法,实现主键去重,详情请参见INSERT ON CONFLIC...
COLUMNS_UPDATEDtests forUPDATEorINSERTactions performed on multiple columns. To test forUPDATEorINSERTattempts on one column, useUPDATE(). COLUMNS_UPDATEDreturns one or more bytes that are ordered from left to right. The rightmost bit of each byte is the least significant bit. The rightmost bit...
COLUMNS_UPDATED tests for UPDATE or INSERT actions performed on multiple columns. To test for UPDATE or INSERT attempts on one column, useUPDATE(). COLUMNS_UPDATED returns one or more bytes that are ordered from left to right, with the least significant bit in each byte being the rightmost....
「資料行存放區索引」是儲存和查詢大型資料倉儲事實資料表的標準。 此索引使用資料行基礎的資料儲存和查詢處理,相較於傳統的資料列導向儲存,最高可在您的資料倉儲中達到 10 倍的查詢效能提升。 相較於未壓縮的資料大小,您也可以將資料壓縮提升高達 10 倍。 從 SQL Server 2016 (13.x) SP1 開始,資料行存放區...