MySQL - INT 数据类型

要通过 JavaScript 程序创建 INT 数据类型的列，我们需要使用 mysql2 库的 query() 函数执行"CREATE TABLE"语句，如下所示 -

sql = "CREATE TABLE students (Id INT AUTO_INCREMENT primary key not null, reg_No INT )";
con.query(sql);

要通过 Java 程序创建 INT 数据类型的列，我们需要使用 JDBC 函数 execute() 执行"CREATE TABLE"语句，如下所示 -

String sql = "CREATE TABLE students(Id INT AUTO_INCREMENT primary key not null, reg_No INT)";
statement.execute(sql);

要通过 Python 程序创建 INT 类型的列，我们需要使用 MySQL Connector/Python 的 execute() 函数执行"CREATE TABLE"语句，如下所示 -

sql = 'CREATE TABLE students (ID int auto_increment, NAME varchar(20), primary key (ID) )'
cursorObj.execute(sql)

var mysql = require("mysql2");
var con = mysql.createConnection({
   host: "localhost",
   user: "root",
   password: "password",
}); //连接到 MySQL

con.connect(function (err) {
   if (err) throw err;
   //console.log("Connected successfully...!");
   //console.log("--------------------------");
   sql = "USE TUTORIALS";
   con.query(sql);
  //create a students table, that accepts one column of int type.
   sql = "CREATE TABLE students (Id INT AUTO_INCREMENT primary key not null, reg_No INT )";
   con.query(sql);
  //将数据插入到创建的表中
   sql = "INSERT INTO students (reg_No) VALUES (101), (102)";
   con.query(sql);
  //select datatypes of salary
   sql = `SELECT DATA_TYPE FROM INFORMATION_SCHEMA.COLUMNS WHERE table_name = 'students' AND COLUMN_NAME = 'reg_No'`;
   con.query(sql, function (err, result) {
      if (err) throw err;
      console.log(result);
   });
});  

输出

生成的输出如下 -

[ { DATA_TYPE: 'int' } ]

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

public class Int {
   public static void main(String[] args) {
      String url = "jdbc:mysql://localhost:3306/TUTORIALS";
      String username = "root";
      String password = "password";
      try {
         Class.forName("com.mysql.cj.jdbc.Driver");
         Connection connection = DriverManager.getConnection(url, username, password);
         Statement statement = connection.createStatement();
         System.out.println("Connected successfully...!");
        //Int data types...!;
         String sql = "CREATE TABLE students(Id INT AUTO_INCREMENT primary key not null, reg_No INT)";
         statement.execute(sql);
         System.out.println("column of a INT type created successfully...!");
         ResultSet resultSet = statement.executeQuery("DESCRIBE students");
         while (resultSet.next()){
            System.out.println(resultSet.getString(1)+" "+resultSet.getString(2));
         }
         connection.close();
      } catch (Exception e) {
         System.out.println(e);
      }
   }
}  

输出

获得的输出如下所示 -

Connected successfully...!
column of a INT type created successfully...!
Id int
reg_No int  

import mysql.connector
# 建立连接
connection = mysql.connector.connect(
   host='localhost',
   user='root',
   password='password',
   database='tut'
)
# 创建游标对象
cursorObj = connection.cursor()
# 创建具有 int 列的表
sql = '''CREATE TABLE students (
ID int auto_increment,
NAME varchar(20),
primary key (ID)
)'''
cursorObj.execute(sql)
print("The table is created successfully!")
# 需要插入的数据
data_to_insert = [
    (1, 'Tilak'),
    (2, 'Akash'),
    (3, 'Surya'),
    (4, 'Deepak'),
    (15, 'Arjun'),
    (16, 'Dev')
]
# 向创建的表中插入数据
insert_query = "INSERT INTO STUDENTS (ID, NAME) VALUES (%s, %s)"
cursorObj.executemany(insert_query, data_to_insert)
# 插入操作后提交更改
connection.commit()
print("Rows inserted successfully.")
# 现在显示表记录
select_query = "SELECT * FROM Students"
cursorObj.execute(select_query)
result = cursorObj.fetchall()
print("Table Data:")
for row in result:
    print(row)
cursorObj.close()
connection.close()  

输出

以下是上述代码的输出 -

The table is created successfully!
Rows inserted successfully.
Table Data:
(1, 'Tilak')
(2, 'Akash')
(3, 'Surya')
(4, 'Deepak')
(15, 'Arjun')
(16, 'Dev')