What are the commands for creating table structures in mysql?

Answer: Use the CREATE TABLE statement to create a table structure. Detailed description: The CREATE TABLE statement is used to create a new table that contains column names, data types, and constraints. Data types include: numerical types, character types, date and time types, and binary types. Constraints limit the data in the table, including: NOT NULL to ensure that the column is not empty, UNIQUE to ensure that the column value is unique, PRIMARY KEY to identify the only record in the table, FOREIGN KEY to associate the columns in the table with other table columns.

MySQL Create Table Structure Command

To create a table structure in MySQL, you can use the following command:

CREATE TABLE statement

CREATE TABLE statement is used to create a new table. The basic syntax is as follows:

<code>CREATE TABLE table_name (
  column_name data_type [constraints]
);</code>

where:

• table_name is the name of the table.
• column_name is the name of the column.
• data_type is the data type of the column, such as INT, VARCHAR or DATETIME.
• constraints are optional constraints, such as NOT NULL or UNIQUE.

Data type

MySQL supports various data types, including:

• Numeric type: INT, FLOAT, DOUBLE
• Character types: CHAR, VARCHAR, TEXT
• Date and time types: DATE, TIME, DATETIME, TIMESTAMP
• Binary types: BINARY, VARBINARY, BLOB

Constraints

Constraints are used to Limit the data in the table. The most commonly used constraints include:

• NOT NULL: NULL values ​​are not allowed for columns.
• UNIQUE: Ensure that the values ​​in the column are unique.
• PRIMARY KEY: The unique record that identifies the table.
• FOREIGN KEY: Relates columns in one table to columns in another table.

Example

Create a table named customers with the following columns:

<code class="sql">CREATE TABLE customers (
  id INT NOT NULL AUTO_INCREMENT,
  name VARCHAR(255) NOT NULL,
  email VARCHAR(255) UNIQUE,
  PRIMARY KEY (id)
);</code>

This command A new table named customers will be created with four columns: id, name, email and PRIMARY KEY. The id column is an auto-incrementing primary key, ensuring that each record has a unique identifier. The name and email columns store the customer's name and email address respectively, and the email column has a unique constraint.

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