Database
DataBase Concepts
DataBase – a collection of information related to specific entity (e.g. organization, bank, college, library etc.)
DBMS – (Database management system) – a application through which we can control the database i.e. we can store data into database, update the data and delete also we can retrieve the data from database. For doing these operation DBMS support a language called Structured Query language (SQL).
SQL accomplishes many powerful tasks with a mere seven statements: SELECT, UPDATE, INSERT, DELETE, CREATE, ALTER, and DROP. Each of these seven statements fall into one of two categories: DML (Data Manipulation Language) statements or DDL (Data Definition Language) statements. These statements are summarized as follows: DML Statements SELECT Enables you to select one or more columns from one or more tables in the database. The results can be simply viewed, or can be used as the basis for a form or report, or, in the case of embedded SQL, can be processed as a temporary table (called a "recordset" in Access, called a "cursor" in other DBMSs). UPDATE Enables you to update the data in one or more columns of one or more rows in a table. INSERT Enables you to append rows to an existing table. DELETE Enables you to delete one or more rows from an existing table. DDL Statements CREATE Enables you to create a new table, or to create a new index on an existing table.
ALTER Enables you to modify the structure of an existing table (by adding or deleting columns). DROP Enables you to delete a table
Consider the Following DataBase: NWINDVBP.MDB
Example 1:
Retrieve all columns and all rows from the Employees table.
Example 2:
Retrieve the Product ID, product name, and unit price from all rows of the Products table: Example 3:
What is the name for product ID 19?
Example 4:
Which customers are from Mexico? (Show Customer ID, company name, contact name, and contact title in the results.) Example 5:
Which employees
DataBase – a collection of information related to specific entity (e.g. organization, bank, college, library etc.)
DBMS – (Database management system) – a application through which we can control the database i.e. we can store data into database, update the data and delete also we can retrieve the data from database. For doing these operation DBMS support a language called Structured Query language (SQL).
SQL accomplishes many powerful tasks with a mere seven statements: SELECT, UPDATE, INSERT, DELETE, CREATE, ALTER, and DROP. Each of these seven statements fall into one of two categories: DML (Data Manipulation Language) statements or DDL (Data Definition Language) statements. These statements are summarized as follows: DML Statements SELECT Enables you to select one or more columns from one or more tables in the database. The results can be simply viewed, or can be used as the basis for a form or report, or, in the case of embedded SQL, can be processed as a temporary table (called a "recordset" in Access, called a "cursor" in other DBMSs). UPDATE Enables you to update the data in one or more columns of one or more rows in a table. INSERT Enables you to append rows to an existing table. DELETE Enables you to delete one or more rows from an existing table. DDL Statements CREATE Enables you to create a new table, or to create a new index on an existing table.
ALTER Enables you to modify the structure of an existing table (by adding or deleting columns). DROP Enables you to delete a table
Consider the Following DataBase: NWINDVBP.MDB
Example 1:
Retrieve all columns and all rows from the Employees table.
Example 2:
Retrieve the Product ID, product name, and unit price from all rows of the Products table: Example 3:
What is the name for product ID 19?
Example 4:
Which customers are from Mexico? (Show Customer ID, company name, contact name, and contact title in the results.) Example 5:
Which employees