This method is useful when we need to update multiple rows with different values based on a specific condition using CASE WHEN. Syntax: UPDATE table_name SET column_name = CASE WHEN condition1 THEN value1 WHEN
mysql>select*fromstudents2;+---+---+---+---+|sid|sname|gender|dept_id|+---+---+---+---+|1|aa|1|1||3|bb|1|1||4|cc|1|1|+---+---+---+---+3rowsinset(0.00sec) mysql>mysql>updatestudents,students2setstudents.sname=students2.snamewherestudents.sid=students2.sid; 3 ...
UPDATEupdates rowsineachtablenamedintable_references that satisfy the conditions. Each matching rowisupdatedonce, evenifit matches the conditions multiple times.Formultiple-tablesyntax,ORDERBYandLIMIT cannot be used.Forpartitioned tables, both thesingle-singleandmultiple-tableformsofthis statement ...
select product_id from orders where id = 100 union select product_id from orders where id = 200; 正解: select product_id from orders where id = 100 union all select product_id from orders where id = 200; 原因: union:对两个结果集进行并集操作,不包括重复行,相当于distinct,同时进行默认规则...
To update the vendor name, type: Update TrnVendor Set Name = 'Genie R Corp.' Where VendId = 'TV001'; To check the vendor name to see that it has changed, type: Select VendId, Name from TrnVendor where VendId = 'TV001';
可以运用在update和delete语句的后面。 where类似程序语言中if条件,根据mysql表中的字段值进行数据的过滤。 eg.查询users表中 age > 22的数据 select * from userswhere age > 22; 查询 users 表中 name=某个条件值 的数据 select * from users where name = '王五'; 查询 users 表中 年龄在22到25...
该库将生成完整的 DELETE、INSERT、SELECT 和 UPDATE 语句,这些语句被格式化以供 MyBatis 或 Spring 使用。最常见的用例是生成语句和一组匹配的参数,MyBatis 可以直接使用它们。该库还将生成与 Spring JDBC 模板兼容的语句和参数对象。 该库通过实现一个类似 SQL 的 DSL 来工作,该 DSL 创建一个包含完整 SQL 语...
3-Inserting Multiple Rows 插入多行 INSERT INTO … VALUES (), (), () 4-Inserting Hierarchical Rows 插入分层行 5-Creating a Copy of a Table 创建表复制 / CREATE TABLE … AS 6-Updating a Single Row 更新单行 / UPDATE … SET … WHERE … ...
specified as amatlab.io.RowFilterobject or a cell array ofmatlab.io.RowFilterobjects. Filters determine which database rowssqlupdatemust update with which data. If multiple database rows match a filter,sqlupdateupdates them with the same data. If a single database row matches multiple filters, ...
A searched update modifies multiple rows when the search condition doesn't uniquely identify a single row. GLOBAL Specifies that cursor_name refers to a global cursor. cursor_name Is the name of the open cursor from which the fetch should be made. If both a global and a local cursor with...