sql server varchar max performance issues

Differences between varchar and nvarchar: Varchar (n)Variable-length and non-Unicode character data with a length of n Bytes. N must be a value between 1 and 8,000. The storage size is the actual length of the input data bytes, rather than n Bytes (such as varchar (6). When the field is qqq, the actual space occupied by the database is 3 bytes, instead of 6 bytes

In SQL Server, when we set character fields, there are often a number of data types for us to choose from, such as: char nchar varchar nvarchar, then we should choose which one? Here's a Yi Yilai description of the difference. char: fixed length, non-Unicode character data, n bytes in length. The value range of n is 1 to 8,000, and the storage size is n bytes. T

In SQL Server, when we set character fields, there are often many data types for us to choose from, such as char nchar varchar nvarchar. Which one should we choose? The differences are described one by one. Char:Fixed Length, non-Unicode character data, length is n Bytes. The value range of n is 1 to 8,000, and the storage size is n Bytes. The synonym for SQL2003

Differences between varchar and nvarchar: Varchar (N)Variable-length and non-UNICODE character data with a length of n Bytes. N must be a value between 1 and 8,000. The storage size is the actual length of the input data bytes, rather than n Bytes (such as varchar (6). When the field is qqq, the actual space occupied by the database is 3 bytes, instead of 6 byt

commonly used character data type.(7) SupplementTEXT Text stores non-Unicode data of variable length, with a maximum length of 2^31-1 (2,147,483,647) characters.NCHAR, NVARCHAR, NTEXTThese three kinds of names from the first three more than the previous "N". Compared to char and varchar, nchar and nvarchar store up to 4,000 characters, whether in English or Chinese characters, while char and varchar can st

Differences between varchar and nvarchar: Varchar (N)Variable-length and non-UNICODE character data with a length of n Bytes. N must be a value between 1 and 8,000. The storage size is the actual length of the input data bytes, rather than n Bytes (such as varchar (6). When the field is qqq, the actual space occupied by the database is 3 bytes, instead of 6 byte

In SQL, the varchar type is converted to int and then sorted, if our database ID is set to varchar type, the order by ID when queried.If the ID of our database is set to the varchar type of the order by ID at the time of the query, we do not want to see the following situation.We can convert

nvarchar, Then the Chinese character is also nvarchar (1), the letter is also nvarchar (1), then already very obvious.at the same time, varchar retrieval is faster than nvarchar. varchar uses a single byte to store data in SQL Server, and nvarchar uses Unico to store data.Chinese characters stored in

In industrial control applications, the returned data is often stored in binary format, and the binary data represents a hexadecimal data content every 4 bits. During parsing, a single byte usually occupies eight digits (BIT). 4 bits at the top indicate a hexadecimal data, and 4 bits at the bottom indicate a hexadecimal data. Problem description: In the SQL Server database, how does one directly conv

Data Types of fixed-length (char) and variable-length (varchar) characters Char [(n)] Character data with a fixed length of n Bytes and is not Unicode. N must be a value between 1 and 8,000. The storage size is n Bytes. The synonym for char in the SQL-92 is character. Varchar [(n)] Variable-length and non-UNICODE character data with a length of n By

for Chinese and other characters, where n represents a Unicode constant, which resolves the problem of conversion between multilingual character sets. The following are supplementary: For fields with generic string types in your program, there are four types of char, varchar, nchar, and nvarchar in SQL Server, so what's the difference between these four types

Select CONVERT (varchar), GETDATE (), 20040912 Select CONVERT (varchar (), GETDATE (), 102) 2004.09.12 Select CONVERT (varchar), GETDATE (), 101 ) 09/12/2004 Select CONVERT (varchar (104), GETDATE (), 103) 12/09/2004 Select CONVERT (varchar), GETDATE (),) 12.09.2004 S

variable length.Vi. How do I use these types?If you are sure of the length of the stored data and do not pack in Chinese, you can choose the char type. If you are sure of the stored data length, but may include Chinese, you can choose the nchar type. If you are unsure of the length of the stored data, store only English, the best use of the number varchar If you are unsure of the length of the stored data, it is possible to have Chinese, you can choo

, without the efficiency of a varchar high. (4) Why use nvarchar? with n prefixes, n denotes Unicode characters, that is, all characters account for two bytes, Nchar,nvarchar Character, the English characters only need one byte storage is sufficient, but the Chinese character is numerous, requires two bytes of storage, English and Chinese characters are prone to confusion, the Unicode character set is to solve the problem of incompatible character set

This article is from the 51cto blog (cannot stop V) Varchar uses a single byte to store data in SQL Server. nvarchar uses Unico to store data. when a Chinese character is stored in SQL Server, it is saved as two bytes (generally Unico encoding), and an English character is

Tags: field issues database SQL statement Refresh SQL Novice Color BSPA field property in SQL Server is varchar, I want to change this field to int type? This is a little annoyed, as a novice to face these problems really a bit di

Conversion: differences between char, varchar, text, nchar, nvarchar, and ntext in SQL Server Many developers often do not consider the char and varchar types when designing databases. Some developers do not pay attention to them because the storage price is getting cheaper and cheaper, I forgot some of the ba

its characters are expressed in two bytes, That is, the English character is also represented in two bytes. the length of the nchar and nvarchar is between 1 and 4000. Compared to char and varchar, nchar and nvarchar store up to 4,000 characters, whether in English or Chinese characters, while char and varchar can store up to 8,000 English and 4,000 Chinese characters. It can be seen that the use of nchar,

do I use these types? If you are sure of the length of the stored data and do not pack in Chinese, you can choose the char type. If you are sure of the stored data length, but may include Chinese, you can choose the nchar type. If you are unsure of the length of the stored data, store only English, the best use of the number varchar If you are unsure of the length of the stored data, it is possible to have Chinese, you can choose the nvarchar type, a

For general string fields in the program, SQL Server has char, varchar, nchar, and nvarchar types. What are the differences between these four types? Here we will make a comparison. 1. Fixed Length or variable length The so-called fixed length is fixed length. when the length of the data to be saved is insufficient, an English space will be automatically filled b