The document provides an overview of SQL statements focused on table creation and the use of aliases for columns in a 'students' table. It also details the functionality of the SQL 'LIKE' operator, which searches for specified patterns in a column using wildcards. Multiple examples illustrate how to use the operator for various query patterns, including selecting records based on specific criteria related to student names.

1. SQL
Statements
INSTRUCTOR:
ELLEN GRACE PORRAS

2. 2
Table Name: Students
Student_ID Firstname Lastname Age Allowance
1100 Fernan Cabuso 22 400
1101 Joshua Guimaras 22 500
1102 Joyce Hisona 21 500
1103 Andrea Laki 20 600
Table Name: Students

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SQL Aliases
SQL aliases are used to give a table, or a column in a table, a
temporary name. Aliases are often used to make column names
more readable. An alias only exists for the duration of that query.
An alias is created with the AS keyword.

4. 4
Table Name: Students
Student_ID Firstname Lastname Age Allowance
1100 Fernan Cabuso 22 400
1101 Joshua Guimaras 22 500
1102 Joyce Hisona 21 500
1103 Andrea Laki 20 600
Example: Alias
SELECT Student_ID AS ID
FROM Students

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Output
ID
1100
1101
1102
1103
Example: Alias
SELECT Student_ID AS ID
FROM Students

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Table Name: Students
Student_ID Firstname Lastname Age Allowance
1100 Fernan Cabuso 22 400
1101 Joshua Guimaras 22 500
1102 Joyce Hisona 21 500
1103 Andrea Laki 20 600
Example: Alias
Select Student_ID as ID, Firstname as Pangalan
from Employees

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Output
ID Pangalan
1100 Fernan
1101 Joshua
1102 Joyce
1103 Andrea
Example: Alias
Select Student_ID as ID, Firstname as Pangalan
from Employees

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The SQL LIKE Operator
The LIKE operator is used in a WHERE clause to search for a specified
pattern in a column.
There are two wildcards often used in conjunction with the LIKE operator:
• The percent sign (%) represents zero, one, or multiple characters
• The underscore sign (_) represents one, single character
• The percent sign and the underscore can also be used in combinations!

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LIKE Operator Description
WHERE Student_Name LIKE 'a%' Finds any values that start with "a"
WHERE Student_Name LIKE '%a' Finds any values that end with "a"
WHERE Student_Name LIKE '%or%' Finds any values that have "or" in any position
WHERE Student_Name LIKE '_r%' Finds any values that have "r" in the second position
WHERE Student_Name LIKE 'a_%'
Finds any values that start with "a" and are at least 2 characters
in length
WHERE Student_Name LIKE 'a__%'
Finds any values that start with "a" and are at least 3 characters
in length
WHERE Student_Name LIKE 'a%o' Finds any values that start with "a" and ends with "o"
Here are some examples showing different LIKE operators with '%' and '_' wildcards:

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Example: LIKE Operator
The following SQL statement selects all records in Students
Table with a FirstName starting with “J". We use the following
LIKE statement:

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Table Name: Students
Student_ID Firstname Lastname Age Allowance
1100 Fernan Cabuso 22 400
1101 Joshua Guimaras 22 500
1102 Joyce Hisona 21 500
1103 Andrea Laki 20 600
Example: Like
SELECT *
FROM Students
WHERE FirstName LIKE ‘J%’;

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Output
Student_ID Firstname Lastname Age Allowance
1101 Joshua Guimaras 22 500
1102 Joyce Hisona 21 500
Example: Like
SELECT *
FROM Students
WHERE FirstName LIKE ‘J%’;

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The following SQL statement selects all records in Students Table with
a LastName ending with “s". We use the following LIKE statement:

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Table Name: Students
Student_ID Firstname Lastname Age Allowance
1100 Fernan Cabuso 22 400
1101 Joshua Guimaras 22 500
1102 Joyce Hisona 21 500
1103 Andrea Laki 20 600
Example: Like
SELECT *
FROM Students
WHERE Lastname LIKE ‘%s’;

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Output
Student_ID Firstname Lastname Age Allowance
1101 Joshua Guimaras 22 500
Example: Like
SELECT *
FROM Students
WHERE Lastname LIKE ‘%s’;

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The following SQL statement selects all records in Students
Table with Firstname that have “Jo” in any position. We use
the following LIKE statement:

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Table Name: Students
Student_ID Firstname Lastname Age Allowance
1100 Fernan Cabuso 22 400
1101 Joshua Guimaras 22 500
1102 Joyce Hisona 21 500
1103 Andrea Laki 20 600
Example: Like
SELECT *
FROM Persons
WHERE Firstname LIKE ‘%Jo%’;

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Output
Student_ID Firstname Lastname Age Allowance
1101 Joshua Guimaras 22 500
1102 Joyce Hisona 21 500
Example: Like
SELECT *
FROM Persons
WHERE Firstname LIKE ‘%Jo%’;

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The following SQL statement selects all records in Students
Table with a Firstname that have “O” in the second position.
We use the following LIKE statement:

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Table Name: Students
Student_ID Firstname Lastname Age Allowance
1100 Fernan Cabuso 22 400
1101 Joshua Guimaras 22 500
1102 Joyce Hisona 21 500
1103 Andrea Laki 20 600
Example: Like
SELECT *
FROM Students
WHERE FirstName LIKE ‘_O%’;

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Output
Student_ID Firstname Lastname Age Allowance
1101 Joshua Guimaras 22 500
1102 Joyce Hisona 21 500
Example: Like
SELECT *
FROM Students
WHERE FirstName LIKE ‘_O%’;

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The following SQL statement selects all records in Students
Table with a Firstname that starts with “j” and ends with “a”.
We use the following LIKE statement:

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Table Name: Students
Student_ID Firstname Lastname Age Allowance
1100 Fernan Cabuso 22 400
1101 Joshua Guimaras 22 500
1102 Joyce Hisona 21 500
1103 Andrea Laki 20 600
Example: Like
SELECT *
FROM Students
WHERE FirstName LIKE ‘j%a’;

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Output
Student_ID Firstname Lastname Age Allowance
1101 Joshua Guimaras 22 500
Example: Like
SELECT *
FROM Students
WHERE FirstName LIKE ‘j%a’;

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The following SQL statement selects all records in Students
Table with a Firstname that does not starts with “j”. We use
the following LIKE statement:

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Table Name: Students
Student_ID Firstname Lastname Age Allowance
1100 Fernan Cabuso 22 400
1101 Joshua Guimaras 22 500
1102 Joyce Hisona 21 500
1103 Andrea Laki 20 600
Example: Like
SELECT *
FROM Students
WHERE FirstName NOT LIKE ‘j%’;

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Output
Student_ID Firstname Lastname Age Allowance
1100 Fernan Cabuso 22 400
1103 Andrea Laki 20 600
Example: Like
SELECT *
FROM Students
WHERE FirstName NOT LIKE ‘j%’;

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Thank you!