MySQL text vs varchar | Top 7 Key Differences You Should Know

34
MySQL text vs varchar | Top 7 Key Differences You Should Know

MySQL text vs varchar | Top 7 Key Differences You Should Know

Difference between MySQL Text vs Varchar

MySQL Varchar defines a data type string with the variable length that stores a value as a length prefix of 1-byte or 2-byte plus actual data. Besides Varchar and Char data types, the MySQL server supports the TEXT data type, including additional features that the previous two do not contain. In this topic, we are going to learn about MySQL text vs varchar.

MySQL Text is a data type in MySQL which is responsible for storing a text data value in the database table. The Text type is beneficial to store the long-form text strings from length 1 byte to 4 GB. Unlike Varchar, we do not need to specify the length storage using Text type for a table column. The length prefix denotes the number of bytes present in a value. Suppose, if a table column needs less than 255 bytes, then a 1-byte length prefix is used. Also, when the column needs more than 255 bytes then, a 2-byte length prefix is used. But the total length for all columns should be to a maximum size of 65,535.

Head to Head Comparison Between MySQL text vs varchar (Infographics)

Below are the top differences between MySQL text and varchar

MySQL-text-vs-Varchar-info

Key differences of MySQL text vs varchar

Below are the key differences between MySQL text vs varchar:

1. VARCHAR

VARCHAR follows the standard ASCII character. This data type uses dynamic memory allocation. For Varchar, the max length for table row size is subjected to be up to 65,535 characters. It means that the columns available in a database table should be of a total length of less than the max size. Suppose, let us illustrate the above with the following example:

We are creating a table having two columns, t1 and t2, which consists of a length of 32765 & 32766, i.e. +2 for length prefix. Here, you can evaluate the row size as 32765+2+32766+2=65535, which is the max size. The query is:

CREATE TABLE IF NOT EXISTS demo (t1 VARCHAR(32765) NOT NULL, t2 VARCHAR(32766) NOT NULL) COLLATE LATIN1_DANISH_CI  CHARACTER SET 'latin1';

Output:

MySQL text vs varchar output 1

The above query will create the table named demo. But when we increment the length size of column t1 by 1 for another table demo2, then the query is executed as follows:

CREATE TABLE IF NOT EXISTS demo2 (t1 VARCHAR(32766) NOT NULL, t2 VARCHAR(32766) NOT NULL) COLLATE LATIN1_DANISH_CI  CHARACTER SET 'latin1';

Output:

MySQL text vs varchar output 2

The server will generate the error message because as we have increased the column size by1 then, the total row size becomes 65536 that is too big. Thus, the query statement becomes fail.

While storing the VARCHAR type values, the MySQL server does not remove spaces. However, the server will maintain the trailing spaces during the insertion or selection of Varchar values.

2. TEXT

On the other side, the Text type values are not kept in the server’s memory of the database. Hence, whenever a user queries Text data, the MySQL server has to view it from the disk. This is a much slower process in comparison to varchar.

MySQL supports four types of Text data: Text, TinyText, MediumText, and LongText.

Let us view the size of all four Text types using a character set (1-byte to store a character):

3. TINYTEXT

This Text type can store a maximum of 255 characters (255 Bytes). If a table column needs less than 255 characters, contains inconsistent length and does not need sorting like the excerpt for a summary of an article or a blog post. To illustrate this, let us view the example below:

CREATE TABLE Books (BookID INT AUTO_INCREMENT PRIMARY KEY, BookName VARCHAR (255), Summary TINYTEXT);

4. TEXT

This TEXT type holds up to 65,535 characters (64KB) and needs 2-bytes overhead. In addition, the text type is able to contain the body of an article. For example:

CREATE TABLE Books (BookID INT AUTO_INCREMENT PRIMARY KEY, BookName VARCHAR (255), Body TEXT NOT NULL);

5. MEDIUMTEXT

This type of Text can store a maximum of 16,777,215 characters (16MB). For the text data, it needs 3-bytes overhead. This Text kind is beneficial to store quite big data such as the text of a white paper, book, etc.

CREATE TABLE Books (BookID INT AUTO_INCREMENT PRIMARY KEY, BookName VARCHAR (255), Body MEDIUMTEXT NOT NULL);

6. LONGTEXT

This Text type can hold 4,294,967,295 characters (4 GB), which is a lot and need 4-bytes overhead. View an example below:

CREATE TABLE Books (BookID INT AUTO_INCREMENT PRIMARY KEY, BookName VARCHAR (255), Body LONGTEXT NOT NULL, Price INT NOT NULL);

Hence, the TEXT type supports a family column kind which is aimed to be a high capacity character storage data type. The tiniest TEXT type named TINYTEXT bonds the identical character length as VARCHAR. The TEXT type holds character strings other than collation and binary character set. Therefore, on the basis of this character set, the sorting and comparisons take place. If the truncation of trailing spaces from the Text values is exceeded when inserting into the table columns, then MySQL often produces a warning irrespective of the SQL mode. This is because the Text table column does not contain any DEFAULT value.

For demonstration:

CREATE TABLE Books (BookID INT AUTO_INCREMENT PRIMARY KEY, BookName VARCHAR (255), Body TEXT NOT NULL, Price INT NOT NULL);
Describe Books;

Output:

Output 3

Comparison Table of MySQL text vs varchar

Following is the comparison table between TEXT and VARCHAR data types in MySQL:

TEXTVARCHAR
It can be used to store paragraph type content.It can be used when we want a sentence or a few words.
It does not index the table column. I needed to state a length prefix.It indexes the entire table column.
It can be useful if the table row size limit is exceeded in the server database.It can be useful when the table column is implemented with foreign key constraints.
It holds a maximum size of 65,535 characters which is not limited.Holds inconstant max size of characters between 1 – 65535.
Text values are stored in the disk-based table, which is temporary (as the HEAP MEMORY Storage engine) and, when queried, reads from it.Varchar values are stored in line with the database table in the server’s memory but without pad spaces.
It has the ability to insert and manage usual long-form text strings in a MySQL database.It inserts variable strings in the server database.
The syntax used with creating a table in MySQL:

CREATE TABLE TableName(ID INT PRIMARY KEY, Description TEXT NOT  NULL );

The syntax used with creating a table in MySQL:

CREATE TABLE TableName(ID INT PRIMARY KEY, Title VARCHAR(255) NOT NULL );

Conclusion

The VARCHAR data type in MySQL can normally be applied for data that includes values like title, name, profile, product name, company names, etc., which holds short content in the table column.

Generally, the data type TEXT in MySQL is used to store the article content body in production description, news sites in websites using e-commerce products.

Recommended Articles

This is a guide to MySQL text vs varchar. Here we discuss the MySQL text vs varchar key differences with infographics and comparison table. You may also have a look at the following articles to learn more –

  1. Wrike vs Asana
  2. Rollup vs Webpack
  3. DSL vs Cable
  4. PIC vs Arduino

The post MySQL text vs Varchar appeared first on EDUCBA.

Source link