$sql="UPDATE another_table SET value = '$value' WHERE id = 'id'";if($conn->query($sql)===TRUE){ echo"数据更新成功";}else{ echo"Error: ".$sql."<br>".$conn->error;} $conn->close();?> 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 饼状图 30%50%20%饼状图连接数据库选择数据...
SELECTname,ageFROMusers; 1. 2. 这将返回users表中所有用户的name和age列的值。 UPDATE SELECT用法 在某些情况下,我们可能需要使用SELECT语句的结果来更新表中的数据。这可以通过将SELECT语句嵌套在UPDATE语句中来实现。具体的用法如下: UPDATEtable_nameSETcolumn1=(SELECTcolumn2FROManother_tableWHEREcondition)WHERE...
update student s set city_name = (select name from city where code = s.city_code); REF: http://dba.stackexchange.com/questions/119621/how-to-update-10-million-rows-in-mysql-single-table-as-fast-as-possible http://stackoverflow.com/questions/6393763/fast-cross-table-update-with-mysql http...
UPDATE table1 t1 SET t1.field_to_update = ( SELECT t2.value_to_set FROM table2 t2 WHERE t1.common_field = t2.common_field LIMIT 1 ) WHERE EXISTS ( SELECT 1 FROM table2 t2 WHERE t1.common_field = t2.common_field ); 3. 使用 FROM 子句(MySQL 8.0+) 在MySQL 8.0及更高版本中,...
INSERT INTO table_name(column_list) SELECT select_list FROM another_table WHERE condition; INSERT ON DUPLICATE KEY UPDATE statement(插入更新数据)如果目标表里已经存在相同的主键,则执行下面的更新字段的SQLINSERT INTO table (column_list) VALUES (value_list) [SELECT ...FROM ... WHERE] ON DUPLICATE ...
Re: Update from another table where partial string exist in other table Sébastien F. May 27, 2022 04:42PM Re: Update from another table where partial string exist in other table Gideon Engelbrecht May 27, 2022 11:54PM Sorry, you can't reply to this topic. It has been closed. ...
UPDATE users SET status = '退休' WHERE age > 30; 子查询更新 代码语言:txt 复制 UPDATE table_name SET column1 = (SELECT new_value FROM another_table WHERE condition) WHERE condition; 例如,根据另一个表中的数据更新当前表中的某个字段: ...
在上述示例中,update_another_table是触发器的名称,table1是要插入数据的表,table2是要更新数据的另一个表,column1是要更新的列,id是用于匹配两个表的关联字段。 插入数据: 代码语言:txt 复制 INSERT INTO table1 (column1, column2) VALUES ('value1', 'value2'); 当执行上述插入语句时,触发器会自动触发...
代码:DELETE [FROM] {table_name|view_name} [WHERE clause] 在SQL SELECT 语句中可以使用的任何条件都可以在DELECT 语句的WHERE子句 中使用。例如,下面的这个DELETE语句只删除那些first_column字段的值为’goodbye’或second_column字段的值为’so long’的记录: ...
Re: Update from another table if substring exists in second table Peter Brawley May 31, 2021 01:02PM Re: Update from another table if substring exists in second table Gideon Engelbrecht June 01, 2021 04:21AM Sorry, you can't reply to this topic. It has been closed....