MySQL UPDATE语句用于更新MySQL数据库表中的记录。
UPDATE语句有3种语法。
UPDATE
table
SET
column1 = expression1,
column2 = expression2,
...
[
WHERE
conditions];
MySQL UPDATE语句的完整语法:
[ LOW_PRIORITY ] [
IGNORE
]
conditions]
ORDER
BY
expression [
ASC
|
DESC
]]
[LIMIT number_rows];
table1
column1 = (
SELECT
expression1
FROM
table2
conditions)
table1, table2, ...
table1.
column
= table2.
AND
conditions;
customers
last_name =
'Anderson'
customer_id = 5000;
将客户表中customer_id为5000的last_name更新为“ Anderson” 。
state =
'California'
,
customer_rep = 32
customer_id > 100;
当要更新多个字段时,用逗号来分隔列/值对。
将customer_id大于100的客户所在州 state 改为'California',customer_rep改为32。
city = (
city
suppliers
suppliers.supplier_name = customers.customer_name)
customer_id > 2000;
这个更新例子只更新customer_id大于2000的所有记录的customers表。当供应商表中的supplier_name与客户表中的customer_name匹配时,将供应商表中的city复制到客户表中的city字段。
customers, suppliers
customers.city = suppliers.city
customers.customer_id = suppliers.supplier_id;
这个示例将把suppliers表中的city字段更新customers表中,其中customer_id与supplier_id要相同。
原文链接:https://codingdict.com/