CoverIntroduction1. How to Retrieve Data From a Single Table1.1. The Five Clauses of the SELECT Statement1.2. Column Specifications1.3. LIKE and REGEXP Operators1.4. Arithmetic Operators1.5. Column Aliases1.6. Comparison Operators1.7. IS NULL, BETWEEN, IN Operators1.8. AND, OR, NOT Logical Operators1.9. DISTINCT Clause2. How to Retrieve Data from Multiple Tables2.1. The JOIN Clause2.2. Joining More Than Two Tables2.3. The OUTER JOIN Clause2.4. How to Code a UNION3. Using Functions3.1. Date Functions3.2. Numeric Functions3.3. String Functions4. How to Insert, Update, Delete Data in Tables4.1. The INSERT Clause With a Column List4.2. The INSERT Clause Without a Column List4.4. The UPDATE Clause With a Column List4.4. The DELETE Clause5. Summary Queries and Aggregate Functions5.1. Aggregate Functions5.2. Grouping Data5.3. Simple GROUP BY Query5.4. Improving the GROUP BY Query5.5. Using the HAVING Clause5.5. Using the HAVING and WHERE Clauses Together5.6. COUNT(column_name) and COUNT(*)5.7. Using the DISTINCT Statement6. Working With Subqueries6.1. The Subquery In a SELECT Statement6.2. The Subquery in an UPDATE statement6.3. Create a Duplicate Table From An Existing Table 6.4. The Subquery In a Delete Statement7. SQL Views7.1. SQL View Explained7.2. Benefits of Using Views7.3. Views That Allow UPDATE Statements8. SQL Indexes8.1. SQL Indexes Explained8.2. Clustered vs. Non-clustered Indexes8.3. Create an Index in Workbench Using an ERD8.4. How to Manually Add an Index to an Existing TableGlossaryIndex
1.3

LIKE and REGEXP Operators

LIKE and REGEXP Operators

  • The LIKE keyword is used with the WHERE clause.
  • The LIKE keyword and can use two symbols as wildcards. The percent ( % ) symbol matches any number of characters and the underscore ( _ ) matches a single character
  • REGEXP keyword allows you to do more complex pattern matching than a LIKE keyword/
  • Some version of REGEXP exists in many computer languages. Refer to the “LIKE and REGEXP” handout for a full list of examples.

Table 2. LIKE Keyword

LIKE Symbol

Description

%

Match any string of characters to the left of the symbol

_

Match a single character

Code Example:

USE world;
SELECT name
FROM country
WHERE name LIKE ‘A%’

Results:

LIKE.png

Table 3. REXEXP Keyword

REGEXP Characters

Description

^

Match the pattern to the beginning of the value being tested.

$

Match the pattern to the end of the value being tested.

.

Matches any single character.

[charlist]

Matches any single character listed within the brackets.

[char1 – char2]

Matches any single character within the given range.

|

Separates two string patterns and matches either one

Code Example:

USE world;
SELECT name
FROM country
WHERE name REGEXP 'g[o,u]';

Results:

REGEXP.png

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