How to use mysql to create table data types

When creating a table in MySQL, you need to specify the data type of the column to define the data type and format it stores. Common data types include integers, floating point numbers, characters, dates and times, and Boolean types. Choosing the appropriate data type affects data storage size, value range, performance, and indexing efficiency. Use data types in CREATE TABLE statements, such as CREATE TABLE users (id INT NOT NULL, name VARCHAR(255) NOT NULL, age SMALLINT NOT NULL, created_at DATETIME NOT NULL).

Data type when creating a table in MySQL

When creating a table in MySQL, you need to Column specifies data type. Data types define the type and format of data that can be stored in a column.

Choose the right data type

Choosing the right data type is very important because it affects the following:

• Data storage size: Different data types have different storage space requirements.
• Data range: A data type defines the range or set of values ​​that are allowed to be stored.
• Performance: Some data types may have better performance than others.
• Indexing: Certain data types can be indexed more efficiently, resulting in faster queries.

Common data types

The following are some of the most commonly used data types in MySQL:

• Integer types: INT, SMALLINT, BIGINT
• Floating point type: FLOAT, DOUBLE
• Character type: CHAR, VARCHAR, TEXT
• Date and time types: DATE, TIME, DATETIME
• Boolean type: BOOLEAN
• Enumeration type: ENUM
• Set type: SET

Specify the data type

When creating the table, use CREATE TABLE statement and specify the data type in the column definition. For example:

<code>CREATE TABLE users (
  id INT NOT NULL,
  name VARCHAR(255) NOT NULL,
  age SMALLINT NOT NULL,
  created_at DATETIME NOT NULL
);</code>

Note

• NOT NULL: The specified column cannot store NULL values.
• Length: For character type, the maximum character length needs to be specified.
• Default value: You can use the DEFAULT clause to specify a default value for a column.
• Constraints: You can use constraints (such as unique constraints or foreign key constraints) to impose additional restrictions on columns.

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