MySQL Text Max Length

TL;DR

A standard MySQL TEXT field can hold up to 65,535 characters in comparison to the commonly used VARCHAR which only holds 255.

In this article we’re going to look at various other options for MySQL column types and when it might be appropriate to use each.

The TEXT Field: Your Go-To for Storing Lots of Text

In MySQL, the TEXT field type is designed for storing large amounts of text. But just how large is “large”?

Let’s take a look.

• A regular TEXT field can hold up to 65,535 characters.
• That’s about 64 kilobytes (KB) of data.
• To put it in perspective, that’s roughly 20 pages of single-spaced text!

But what if you need to store even more text? Don’t worry, MySQL has you covered with some supersized options:

• MEDIUMTEXT can store up to 16,777,215 characters (about 16 megabytes or MB).
• LONGTEXT takes it to the extreme with 4,294,967,295 characters (about 4 gigabytes or GB).

How Does TEXT Compare to Other Field Types?

Let’s compare TEXT to some other common field types in MySQL such as the commonly used CHAR and VARCHAR types.

1. CHAR and VARCHAR:

   • CHAR is for fixed-length strings up to 255 characters.
   • VARCHAR can hold variable-length strings up to 65,535 characters.
   • TEXT is similar to VARCHAR but is stored differently and can’t have a default value.

2. BLOB (Binary Large Object):

   • Similar to TEXT but for storing binary data (like images or files).
   • Has the same size variants: BLOB, MEDIUMBLOB, and LONGBLOB.

3. INT (Integer):

   • For storing numbers.
   • The largest INT can hold values up to about 2 billion (much smaller than TEXT).

So, if you’re dealing with lots of text, TEXT and its larger siblings are your best bet.

What Happens If You Try to Store Too Much?

Let’s say you try to insert a novel into a regular TEXT field. What happens?

1. MySQL will truncate (cut off) your data at the maximum length.
2. You won’t get an error message by default.
3. The extra data is simply lost.

This silent truncation can lead to data loss if you’re not careful. Always ensure your application checks the length of text before inserting it into the database.

Best Practices for Using TEXT Fields

1. Choose the right size:

   • Use TEXT for most cases.
   • Only use MEDIUMTEXT or LONGTEXT if you’re sure you’ll need that much space.

2. Consider performance:

   • Larger text fields can slow down your database.
   • If you frequently search within these fields, consider using full-text indexing.

3. Validate input:

   • Always check the length of your text before inserting it into the database.
   • Inform users if their input exceeds the limit.

4. Use compression:

   • If you’re really tight on space, you can compress text before storing it.
   • Just remember to decompress it when retrieving!

Conclusion

Understanding the limits of MySQL text fields is crucial for effective database design. While TEXT fields offer generous space for storing data, it’s important to choose the right type for your needs and handle potential overflow situations gracefully.

Remember, in the world of databases, it’s always better to have a little too much space than not enough.