SQL Create Table with Indexes.

Adding an Index When You Create a Table. Consider you have a tbl_student table and you want student_id as primary key:. Primary key as index. Explanation. One way is to add an index when you first create a table. An index is a data structure that allows us to add indexes in the existing table. Indexes of two types can be added: when you define a primary key, MySQL will take it as index by default. How to Create Index in MySQL.

Example. Here’s an example of how to create an index on a MySQL database table. ALTER TABLE `tbl_student` ADD PRIMARY KEY (`student_id`) It creates an entry for each value of the indexed columns. Creating Tables Using PHP Script. This MySQL CREATE TABLE example creates a table called contacts which has 4 columns and one primary key: The first column is called contact_id which is created as an INT datatype (maximum 11 digits in length) and can not contain NULL values. Creating Indexes with the CREATE TABLE statement In some RDBMS you can create indexes with the CREATE TABLE statement. It enables you to improve the faster retrieval of records on a database table. Here’s a simple table containing three columns to hold the first and last name and email address of a … In most cases, MySQL won't be able to use more than one index for each table in the query (excluding very specific cases of index merges). An index creates an entry for each value that appears in the indexed columns. The following program is an example to create a table using PHP script −
Just as there are multiple types of indexes there are multiple ways to create or add them to MySQL tables. Therefore, when creating a separate index for each column in the table, the database is bound to perform only one of the search operations using an index, and the rest of them will be significantly slower, as the database can't use an index to execute them. This MySQL tutorial explains how to create, drop, and rename indexes in MySQL with syntax and examples. An index is a performance-tuning method of allowing faster retrieval of records. MySQL Database MySQL Connect MySQL Create DB MySQL Create Table MySQL Insert Data MySQL Get Last ID MySQL Insert Multiple MySQL Prepared MySQL Select Data MySQL Where MySQL Order By MySQL Delete Data MySQL Update Data MySQL Limit Data PHP XML PHP XML Parsers PHP SimpleXML Parser PHP SimpleXML - Get PHP XML Expat PHP XML DOM PHP - AJAX MySQL FAQ: How do I create a MySQL or MariaDB database table index?.

You will pass its second argument with a proper SQL command to create a table. To create new table in any existing database you would need to use PHP function mysql_query().