It Sql Final Essay

Submitted By tikinmti
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Pages: 9

DATABASE FINAL EXAM:
What does the update command do?
It allows you to update data.
What do the inner/full outer join commands do?
The INNER JOIN keyword selects all rows from both tables as long as there is a match between the columns in both tables.
The FULL OUTER JOIN keyword returns all rows from the left table (table1) and from the right table (table2). The FULL OUTER JOIN keyword combines the result of both LEFT and RIGHT joins.
What does the Alias command do?
SQL aliases are used to give a database table or a column in a table, a temporary name. Basically aliases are created to make column names more readable.
What does the Like keyword have in it?
The LIKE operator is used to search for a specified pattern in a column. (Example below)
SELECT column_name(s)
FROM table_name
WHERE column_name LIKE pattern;
What are examples of Where clauses?
The WHERE clause is used to extract only those records that fulfill a specified criterion. (Examples below) (1) SELECT column_name,column_name FROM table_name
WHERE column_name operator value; (2) SELECT * FROM Customers WHERE Country='Mexico'; (3) SELECT * FROM Customers
WHERE CustomerID=1;

Is there an “Or “in a Where clause?
The AND operator displays a record if both the first condition AND the second condition are true.
The OR operator displays a record if either the first condition OR the second condition is true.
The following operators can be used in the WHERE clause: Operator | Description | = | Equal | <> | Not equal. Note: In some versions of SQL this operator may be written as != | > | Greater than | < | Less than | >= | Greater than or equal | <= | Less than or equal | BETWEEN | Between an inclusive range | LIKE | Search for a pattern | IN | To specify multiple possible values for a column |
What are examples of There, Where clause?
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What is the Count = function? And, what does it do?
The COUNT(column_name) function returns the number of values (NULL values will not be counted) of the specified column: (Examples below) 1. SELECT COUNT(column_name) FROM table_name; 2. SELECT COUNT(*) FROM table_name;

What are the differences between Insert, Update, and Delete (Involving data)?
INSERT: The INSERT INTO statement is used to insert new records in a table. (Example below each one)
The first form does not specify the column names where the data will be inserted, only their values:
INSERT INTO table_name VALUES (value1,value2,value3,...);
The second form specifies both the column names and the values to be inserted:
INSERT INTO table_name (column1,column2,column3,...) VALUES (value1,value2,value3,...);
UPDATE: The UPDATE statement is used to update existing records in a table.
DELETE: The DELETE statement is used to delete rows in a table.
How do you drag a Relationship within a diagram?
You drag a Relationship from the higher end to the Parent table and the other end to the Child table.
What are the 2 Database parts?
DDL: Data Definition Language and DML: Data Manipulation Language
What action does Select * perform?
The SELECT statement is used to select data from a database. The result is stored in a result table, called the result-set. (Example below) 1. SELECT column_name,column_name
FROM table_name; and 2. SELECT * FROM table_name;

What are the different data types? And, what is their purpose?
Each column in a database table is required to have a name and a data type. SQL developers have to decide what types of data will be stored inside each and every table column when creating a SQL table. The data type is a label and a guideline for SQL to understand what type of data is expected inside of each column, and it also identifies how SQL will interact with the stored data.
General Data type, Microsoft Access Data, MySQL Data, Server Data have a combination of the following: TEXT, NUMBER, DATE, STRING
What is the difference between a