MySQL has many data types for storing string data in the table. VARCHAR and TEXT are two of them. Both can store a maximum of 65535 characters, but there are some differences between these data types described i
Learn about the key differences between CHAR and NCHAR data types in MySQL, including storage requirements and usage scenarios.
show processlist;查看所有登录到mysql的用户进程 服务器: 提供了各种借口(增删改查...),分析器组件会解析用户的sql语句,如果发现sql语句执行的效率较低,会提交给优化器组件进行优化,然后再执行;(查询缓存:把上次搜过的数据,或者把提前存储的数据直接返回,加快效率);(优化器:mysql query optimizer) 存储引擎: 存储...
Varchar and enum approaches look pretty much the same for a human eye. On the other hand, the integer is not human-readable. Then you see status=1, you have no way to say what status is just by looking into the database, and you have to keep the mapping between numbers and words ...
Any difference between Server.MapPath("~") and Server.MapPath("") ? Any easy way to log user activity after they login? Any event after the page load completed? API GET:Obj ref not set to an instance of an object App_code folder in asp.net 3.5 App_Code folder vs. regular folder Ap...
MySQL data types: CHAR, VARCHAR, INT, TEXT #Part-1 MySQL date and time DataTypes Overview: DATE, TIME, DATETIME, TIMESTAMP, YEAR & Zero Values #Part2.1 Automatically insert Current Date and Time in MySQL table #Part – 2.2 MySQL: Working with date time arithmetic #Part 2.3.1 ...
I have a table where is stored position of a word in a text and i would like to create an index on difference between positions of every two words in the same text. This index would increase speed of my queries, because I have a condition in my sql statement like this: WHERE tab1...
ALTERTABLEtable_name CHANGE column_name column_nameVARCHAR(191)CHARACTERSETutf8mb4COLLATEutf8mb4_unicode_ci; Please note that you'll have to consider the consequences of increasing the column size from 3 bytes per character to 4. For example, MySQL indexes are limited to 768 bytes. This means...
Adding varchar(8) in time format that totals more than 24 hrs in SQL Additional Column With BULK INSERT Adventureworks query about sales AFTER INSERT and AFTER UPDATE triggers on same table After INSERT Trigger question - how to use value from last added record Age Bucket in sql Age calculati...
Re: VARCHAR A column uses one length byte if values require no more than 255 bytes, two length bytes if values may require more than 255 bytes. https://dev.mysql.com/doc/refman/5.5/en/char.html Subject Views Written By Posted Is there any difference between varchar(50) and varchar(255...