一、LEFT() 函数 二、RIGHT() 函数 三、SUBSTRING() 函数 1.SUBSTRING(string,position) 2.SUBSTRING(string,position,length) 四、SUBSTRING_INDEX() 函数 五、实战操作 附、一张心酸的照片 声明一下:在MySQL中,下标索引是从1开始的,而不是像java中从0开始的喔! 一、LEFT() 函数 LEFT(string,lengt...
LEFT(string,length) ,从字符串string右边第一位开始,截取长度为length个字符,仍然是正向顺序截取。length应大于0,如<=0,返回空字符串。 mysql>SELECTRIGHT('www.csdn.net',5)fromweb_infow;+---+|RIGHT('www.csdn.net',5)|+---+|n.net|+---+1rowinset(0.00sec) 三、SUBSTRING() 函数 substring()...
SUBSTRING_INDEX(str, delim, count): 返回以delim为分隔符的字符串str的第count个子字符串。 LENGTH(str): 返回字符串str的长度。 TRIM([BOTH | LEADING | TRAILING] [remstr] FROM str): 去除字符串str中的指定的前导、尾随或者两端的字符remstr。 REPLACE(str, from_str, to_str): 替换字符串str中的...
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时间是一类重要的数据,MySQL中有多种关于时间的类型可以选择。这篇文章主要介绍MySQL中的时间类型,主要参考MySQL文档:https://dev.mysql.com/doc/refman/8.0/en/date-and-time-types.html 1. 时间类型 MySQL中的时间类型有三大类:日期(Date)、时间(Time)和年(Year)。
Object[] parameters = result.getParameters(); String name=""; //如果有参数,则使用参数的toString组合代替报告中的name for(Object param:parameters){ name+=param.toString(); } if(name.length()>0){ if(name.length()>50){ name= name.substring(0,49)+"..."; ...
LENGTH (string ) //string长度 LOAD_FILE (file_name ) //从文件读取内容 LOCATE (substring , string [,start_position ] ) 同INSTR,但可指定开始位置 LPAD (string2 ,length ,pad ) //重复用pad加在string开头,直到字串长度为length LTRIM (string2 ) //去除前端空格 ...
select * from users where username=$username (and | or) if(length(database())>8,sleep(3),1) 如果数据库名的长度大于8,那么if条件将执行sleep(3),那么此条语句将进行延迟3秒的操作。若小于或等于8,则if条件直接返回1,并与前边的逻辑连接词拼接,无延迟直接返回。通常的响应时间在0-1秒之内,与上种...
In the namesha256_password,“sha256”refers to the 256-bit digest length the plugin uses for encryption. In the namecaching_sha2_password,“sha2”refers more generally to the SHA-2 class of encryption algorithms, of which 256-bit encryption is one instance. The latter name choice leaves ro...
table - a string of the table the field came from. name - a string of the field name. type - a string of the field type in all caps. length - a number of the field length, as given by the database. The next argument is a function that, when called, will return the default ty...