-- 更新语句(子查询写法)UPDATET_StudentsSETRemark='考过满分'WHEREIdIN(SELECTt.StudentIdFROMT_ExamResults tWHEREt.Scores=100);-- 更新语句(连接写法)UPDATET_StudentsSETRemark='考过满分'FROMT_Students t1JOINT_ExamResults t2ONt1.Id=t2.StudentIdANDt2.Scores=100;-- 删除语句(子查询写法)DELETET_...
Method 4: Updating with Subquery in MySQL Advanced Methods of Using the UPDATE Statement in MySQL Method 1: Using UPDATE with INNER JOIN in MySQL Method 2: Using UPDATE with LEFT JOIN in MySQL Method 3: Using UPDATE with RIGHT JOIN in MySQL Method 4: Using UPDATE with SELF JOIN in MySQ...
sql="select * from 数据表 where 字段名 in ('值1','值2','值3')" sql="select * from 数据表 where 字段名 between 值1 and 值2" (2) 更新数据记录: sql="update 数据表 set 字段名=字段值 where 条件表达式" sql="update 数据表 set 字段1=值1,字段2=值2 …… 字段n=值n where 条件...
SQL Server supports the standard SQL to update the data in the table. Use the UPDATE TABLE statement to update records in the table in SQL Server. Syntax: UPDATE table_name SET column_name1 = new_value, column_name2 = new_value, ... [WHERE Condition]; ...
Look at an example of a subquery, which is a query that is nested in a SELECT, INSERT, UPDATE, or DELETE statement, or inside another subquery in SQL Server.
SET category_id = 5; Conclusion Using a subquery in an UPDATE statement can be a good way to improve the maintainability of your queries. It can also reduce the number of steps required to update your data by compressing two or more queries into a single query. ...
SQLAlchemy 插入更新SQL server数据库 sqlalchemy使用 SQLAlchemy介绍和基本使用 数据库是一个网站的基础。Flask可以使用很多种数据库。比如MySQL,MongoDB,SQLite,PostgreSQL等。这里我们以MySQL为例进行讲解。而在Flask中,如果想要操作数据库,我们可以使用ORM来操作数据库,使用ORM操作数据库将变得非常简单。
-- Syntax for SQL Server and Azure SQL Database [ WITH <common_table_expression> [...n] ] UPDATE [ TOP ( expression ) [ PERCENT ] ] { { table_alias | | rowset_function_limited [ WITH ( <Table_Hint_Limited> [ ...n ] ) ] } | @table_variable } SET { column_name = {...
A subquery is a SELECT statement embedded in another SQL statement, such as a SELECT, INSERT, DELETE, or UPDATE statement. The set of value(s) returned by the inner SELECT statement are passed to the outer SQL statement. The inner SELECT statement is always embraced in parentheses. The resu...
UPDATE users SET age = 30 WHERE id = (SELECT user_id FROM orders WHERE status = 'completed' GROUP BY user_id LIMIT 1); 参考链接 MySQL UPDATE Statement MySQL Subquery 通过以上方法,可以有效解决SQL UPDATE语句中子查询返回多行导致的错误1242问题。相关...