Page 65 - Modular_V2.0_SQL_Flipbook

Standard Index in MySQL is created using the following syntax:

CREATE INDEX index_name ON table_name (column_name);
An index for table STUDENTS is created as follows:

STUDENTS

Stu_id Stu_name Class City
1 Aisha 10A Mumbai
2 Ravi 10B Delhi
3 Sara 10A Kolkata
4 Ali 10C Chennai
5 Neha 10A Delhi

CREATE INDEX idx_city ON STUDENTS(City);
This index will simplify and quicken the search process for finding any desired data in table
STUDENTS.
Let‘s discuss the different types of MySQL Indexes, each used for different purpose:

1. Primary Index: This index is associated with the creation of primary key. It provides a unique
identity to each row and does not allow NULL values.
-- Primary Index

ALTER TABLE table_name
ADD PRIMARY KEY (column_name);
2. Unique Index: This index is associated with the application of unique constraint to a column. A
table can have multiple unique indexes.
-- Unique Index

CREATE UNIQUE INDEX index_name
ON table_name(column_name);
3. Full-Text Index: This type of index works with columns that have large quantities of text and
it helps in quick data-based searches.

-- Full-Text Index
CREATE FULLTEXT INDEX index_name
ON table_name(text_column_name);
4. Composite Index: This type of index is created with the creation of a composite primary key is
defined, where more than one column is used to uniquely identify a row. It helps in resolving
queries that work on multiple columns.

-- Composite Index
CREATE INDEX index_name
ON table_name(column1, column2);
5. Spatial Index: It works effectively on spatial data that is formed over geographical data types.

-- Spatial Index
CREATE SPATIAL INDEX index_name
ON table_name(spatial_column_name);

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Advanced Features of MySQL