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Khóa học miễn phí MariaDB – Create Tables nhận dự án làm có lương

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MariaDB – Create Tables

In this chapter, we will learn how to create tables. Before creating a table, first determine its name, field names, and field definitions.

Following is the general syntax for table creation −

CREATE TABLE table_name (column_name column_type);

Review the command applied to creating a table in the PRODUCTS database −

databaseproducts_ tbl(
   product_id INT NOT NULL AUTO_INCREMENT,
   product_name VARCHAR(100) NOT NULL,
   product_manufacturer VARCHAR(40) NOT NULL,
   submission_date DATE,
   PRIMARY KEY ( product_id )
);

The above example uses “NOT NULL” as a field attribute to avoid errors caused by a null value. The attribute “AUTO_INCREMENT” instructs MariaDB to add the next available value to the ID field. The keyword primary key defines a column as the primary key. Multiple columns separated by commas can define a primary key.

The two main methods for creating tables are using the command prompt and a PHP script.

The Command Prompt

Utilize the CREATE TABLE command to perform the task as shown below −

root@host# mysql -u root -p
Enter password:*******
mysql> use PRODUCTS;
Database changed
mysql> CREATE TABLE products_tbl(
   -> product_id INT NOT NULL AUTO_INCREMENT,
   -> product_name VARCHAR(100) NOT NULL,
   -> product_manufacturer VARCHAR(40) NOT NULL,
   -> submission_date DATE,
   -> PRIMARY KEY ( product_id )
   -> );
mysql> SHOW TABLES;
+------------------------+
| PRODUCTS               |
+------------------------+
| products_tbl           |
+------------------------+

Ensure all commands are terminated with a semicolon.

PHP Create Table Script

PHP provides mysql_query() for table creation. Its second argument contains the necessary SQL command −

<html>
   <head>
      <title>Create a MariaDB Table</title>
   </head>

   <body>
      <?php
         $dbhost = ''localhost:3036
         $dbuser = ''root
         $dbpass = ''rootpassword
         $conn = mysql_connect($dbhost, $dbuser, $dbpass);
      
         if(! $conn ){
            die(''Could not connect: '' . mysql_error());
         }
         echo ''Connected successfully<br />
         
         $sql = "CREATE TABLE products_tbl( ".
            "product_id INT NOT NULL AUTO_INCREMENT, ".
            "product_name VARCHAR(100) NOT NULL, ".
            "product_manufacturer VARCHAR(40) NOT NULL, ".
            "submission_date DATE, ".
            "PRIMARY KEY ( product_id )); ";
      
         mysql_select_db( ''PRODUCTS'' );
         $retval = mysql_query( $sql, $conn );
      
         if(! $retval ) {
            die(''Could not create table: '' . mysql_error());
         }
         echo "Table created successfullyn";
         
         mysql_close($conn);
      ?>
   </body>
</html>

On successful table creation, you will see the following output −

mysql> Table created successfully

Khóa học lập trình tại Toidayhoc vừa học vừa làm dự án vừa nhận lương: Khóa học lập trình nhận lương tại trung tâm Toidayhoc

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