MySQL 5.7 Reference Manual Including MySQL NDB Cluster 7.5 and NDB Cluster 7.6

11.1.3 String Type Overview

A summary of the string data types follows. For additional information about properties and storage requirements of the string types, see Section 11.4, “String Types”, and Section 11.8, “Data Type Storage Requirements”.

In some cases, MySQL may change a string column to a type different from that given in a CREATE TABLE or ALTER TABLE statement. See Section, “Silent Column Specification Changes”.

MySQL interprets length specifications in character column definitions in character units. This applies to CHAR, VARCHAR, and the TEXT types.

Column definitions for character string data types CHAR, VARCHAR, the TEXT types, ENUM, SET, and any synonyms) can specify the column character set and collation:

Character column comparison and sorting are based on the collation assigned to the column. For the CHAR, VARCHAR, TEXT, ENUM, and SET data types, you can declare a column with a binary (_bin) collation or the BINARY attribute to cause comparison and sorting to use the underlying character code values rather than a lexical ordering.

For additional information about use of character sets in MySQL, see Chapter 10, Character Sets, Collations, Unicode.