游标(cursor)是系统为用户开设的一个数据缓冲区,存放SQL语句的执行结果。每个游标区都有一个名字,用户可以用SQL语句逐一从游标中获取记录,并赋给主变量,交由主语言进一步处理。 游标是处理结果集的一种机制吧,它可以定位到结果集中的某一行,多数据进行读写,也可以移动游标定位到你所需要的行中进行操作数据。一般...
Think of it this way: aSQL result is like a bag, you get to hold a whole bunch of rows at once, but not any of them individually; whereas,a cursor is like a pair of tweezers. With it, you can reach into the bag and grab a row, and then move onto the next. ...
在创建时,默认游标类型为pymysql.cursors.Cursor,可自行指定为其他游标类型,例如cur=conn.cursor(cursor=pymysql.cursor.DictCursor) pymysql.cursors.Cursor以元组形式返回sql执行结果 返回的结果中不含列名,仅包括数据 ((425, 'mike', '15166668765',0),) pymysql.cursors.DictCursor以列表字典 [dict, dict] 形...
Scalar functions can be used wherever an expression is valid. Categories of scalar functions Expand table Function categoryDescription Configuration Functions Return information about the current configuration. Conversion Functions Support data type casting and converting. Cursor Functions Return information ...
I almost always use a cursor to loop through records when necessary. The cursor format is a lit...
Transact-SQL, known as T-SQL for short, is a set of programming extensions that enhances the capabilities of Structured Query Language (SQL). Read more.
A USE database statement is not allowed in a procedure, function or trigger. A week this year Against a week this time last year in SQL (NOT MDX) A WITH keyword and parenthesis are now required Accent Sensitivity Access Code - DELETE Statement with DISTINCTROW and T-SQL Access Now() vs...
I have the table to the left, I would like to get the right table as a result, I don't know how many columns there will be, is this possible in SQL...
SQL/CLR UDT XMLSchemaCollection (XML supported) Cursor,RowVersion,Timestamp,Hierarchyid Unsupported column types Data Sync can't sync read-only or system-generated columns. For example: Computed columns System-generated columns for temporal tables ...
Rows to columns This is my source table. I use this script but the output is not aligned,iIwant that the same date is aligned. SELECT top 10 empno , [0] as [punch_code0] , [1] as [punch_code1] , [2] as [punch_code2]...