（1）修改不存在外键约束的多个数据表

情况一：修改没有外键关联，但存在逻辑关系的多个数据表

UPDATE 数据表1 别名,数据表2 别名
SET
数据表1.列名= 数据值
数据表2.列名= 数据值
where 条件语句（表之间的逻辑关系）

案例：

UPDATE student s1,studentquery s2
SET
s1.studentname = '张er',s1.studentpassword = '145263',
s2.studentage = 24,s2.studentlocal = '大腿',s2.studentphone = '1456'
where  s1.studentid=s2.studentid and s1.studentid = 1813004526;

情况二：修改没有外键关联，且不存在逻辑关系的多个数据表

步骤一：在数据库连接文件打开批量操作，否者报 BadSqlGrammarException 错误

allowMultiQueries=true

步骤二：编写批量操作语句

UPDATE SET 数据表一.字段名 = 值 WHERE 子句；
UPDATE SET 数据表二.字段名 = 值 WHERE 子句；

案例：

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/db.nuc?useSSL=true&useUnicode=true&characterEncoding=utf8&allowMultiQueries=true
jdbc.username=root
jdbc.password=root

UPDATE SET student.studentid= 1813004860 WHERE studentname = '李四';
UPDATE SET studentquery.studentid= 1813004860 WHERE studentclass = '18';

（2）修改存在外键约束的多个数据表

UPDATE 数据表1 别名
LEFT JOIN 数据表2 别名 ON 外键约束关系
SET
数据表1.列名= 数据值
数据表2.列名= 数据值
where 条件语句

案例：

UPDATE student s1
LEFT JOIN studentquery s2 ON s1.studentid=s2.studentid
SET
s1.studentname = '张a',s1.studentpassword = '145263',
s2.studentage = 2,s2.studentlocal = '大腿',s2.studentphone = '1456'
where  s1.studentid=s2.studentid and s1.studentid = 1813004526;

1) Oracle 多表更新方法：

     Oracle语法: UPDATE updatedtable SET (col_name1[,col_name2...])= (SELECT col_name1,[,col_name2...] FROM srctable [WHERE where_definition])

     例子：UPDATE A a  SET (a.a1,a.a2)=(SELECT b.b1,b,b2 FROM B b WHERE b.b3=a.a3)

2) MySql多表更新方法：

    MySql语法：UPDATE table_references SET col_name1=expr1 [, col_name2=expr2 ...] [WHERE where_definition]

   例子：UPDATE A a , B b SET a.a1 = b.b1 , a.a2 = b.b2 WHERE a.a3 = b.b3

3) SQLServer多表更新方法：

  SQLServer语法：UPDATE { table_name WITH ( < table_hint_limited > [ ...n ] ) | view_name | rowset_function_limited } SET { column_name = { expression | DEFAULT | NULL } | @variable = expression | @variable = column = expression } [ ,...n ] { { [ FROM { < table_source > } [ ,...n ] ] [ WHERE < search_condition > ] } | [ WHERE CURRENT OF { { [ GLOBAL ] cursor_name } | cursor_variable_name } ] } [ OPTION ( < query_hint > [ ,...n ] ) ]

  例子：UPDATE a SET a.a1 = b.b1 , a.a2 = b.b2 FROM A a , B b WHERE a.a3 = b.b3