Mysql -- index,

Mysql -- index,
1. Create and view Indexes

Common indexes are created without any restrictions (unique or non-empty ). This type of index can be created on any data type field.

(1) create a common index when creating a table

• Syntax:

• Example:

(2) create a common index on an existing table

Syntax:

Example:

2. Create and view unique Indexes

(1) create a unique index when creating a table

• Syntax:

• Example:

(2) create a unique index on an existing table

• Syntax:

• Example:

(3) Use the SQL statement ALTER TABLE to create a unique index

• Syntax:

• Example:

3. Create and view full-text indexes

Full-TEXT indexes are mainly associated with fields with CHAR, VARCHAR, and TEXT data types, so that you can query string fields with large data volumes more quickly.

(1) create a full-text index when creating a table

• Syntax:

• Example:

(2) create a full-text index on an existing table

• Syntax:

• Example:

(3) Use the SQL statement ALTER TABLE to create a full-text index

• Syntax

• Example

4. delete an index

• Syntax:

• Example: