替换某个字段,replace可以替换某个字段中的指定的某个部分,replace(column_name,oldregexstr,newreplacestr) 替换表一行,如果原表中有该条数据,那么会将该条数据删除;如果原表中没有该条数据,则会插入指定值 mysql> selectreplace('12_34_56','_','&'); +---+ |replace('12_34_56','_','&') | ...
先删除,再重新插入 replace into mysql> replace into test(`uniq_flag`) values('amu-2'); Query OK, 2 rows affected (0.00 sec) 注意:对业务需求没有影响可以使用,假如存在对数据的统计等等有负面影响则推荐使用第一种方案,程序做兼容判断处理 (可以推荐使用) 12、未知的字段名 name(小伙伴提交review发现...
In other words, I have a table. I have 100 entries in that table. I would like to replace the values for all rows in one specific column. All of the values in the rows for all of the values in that one column are empty.
ON DUPLICATE KEY UPDATE column = value [, column = value] ... 如果不存在就插入,存在发生主键或者唯一键冲突不要报错,接着执行后面的修改语句。 代码语言:javascript 代码运行次数:0 运行 AI代码解释 insert into students values (14, 111, '周瑜', '56321') on duplicate key update sn=111, name='...
mysql> create table stu1( -> id tinyint, # 范围要尽可能小,范围越小,占用空间越少 -> name varchar(20) -> ); Query OK, 0 rows affected (0.02 sec) -- 超出范围会报错 mysql> insert into stu1 values (128,'tom'); ERROR 1264 (22003): Out of range value for column 'id' at row ...
--1、创建加密函数 AES_ENCRYPT_CLOB CREATE OR REPLACE FUNCTION AES_ENCRYPT_CLOB (V_STR CLOB, V_KEY VARCHAR2) RETURN BLOB AS V_KEY_RAW RAW (32); V_RETURN_STR BLOB; V_TYPE PLS_INTEGER; BEGIN V_KEY_RAW := UTL_I18N.STRING_TO_RAW (V_KEY, 'UTF8'); V_TYPE := DBMS_CRYPTO....
replace into - 向数据库表中插入数据,如果存在先删除 load - 载入数据 1. 2. 3. 4. 5. TCL (Transaction Control Language,事务控制语言)又名TPL(Transaction Process Language)事务处理语言,它能确保被DML语句影响的表的所有行及时得以更新。TPL语句包括: ...
SET column_1 = value_1, column_2 = value_2, ... WHERE condition; 例如: 将选修“徐军”老师所教所有课堂的同学的成绩提高5% UPDATE sc JOIN teaching AS t ON sc.Cid = t.Cid JOIN teacher ON teacher.Tno = t.Tno JOIN student AS s ON sc.Sno = s.Sno ...
VALUES (value1 [,value2, …, valuen]);12为表的指定字段插入数据,就是在INSERT语句中只向部分字段中插入值,而其他字段的值为表定义时的默认值。在INSERT 子句中随意列出列名,但是一旦列出,VALUES中要插入的value1,…valuen需要与column1,…columnn列一一对应。如果类型不同,将无法插入,并且MySQL会产生错误...
column(s). If None is given (default) and index is True, then the index names are used. A sequence should be given if the DataFrame uses MultiIndex.chunksize : int, optionalRows will be written in batches of this size at a time. By default, all rows will be written at once.dtype ...