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learn sql server online tutorial | TechandMate

Learn SQL Server online tutorial, which provides a descriptive learning of the Database concepts along with the working of the relational databases.<br>

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learn sql server online tutorial | TechandMate

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  1. Introduction to Structured Query Language (SQL) Learn SQL Server With US By Techandmate.com

  2. Objectives • Explore basic commands and functions of SQL • How to use SQL for data administration (to create tables, indexes, and views) • How to use SQL for data manipulation (to add, modify, delete, and retrieve data) • How to use SQL to query a database to extract useful information

  3. Agenda • What is SQL ? • Data Types  • Constraints • Database Relationships • SQL Queries  • Transact- SQL Commands | DDL , DCL ,DML • Retrieving Data • Customizing Data • Grouping Data • SQL Operators  • Joining Data

  4. Agenda continue • Inserting , Updating and Deleting Data • Working With Tables • Working with Views • Working With Constraints  • Generating Scripts  • Working with Stored Procedures • Working  with Functions

  5. Introduction to SQL • SQL stands for Structured Query Language. SQL is used to communicate with a database. According to ANSI (American National Standards Institute), it is the standard language for relational database management systems • SQL functions fit into two broad categories: • Data definition language • SQL includes commands to: • Create database objects, such as tables, indexes, and views • Define access rights to those database objects • Data manipulation language • Includes commands to insert, update, delete, and retrieve data within database tables

  6. SQL Database Objects • A SQL Server database has lot of objects like • Tables • Views • Stored Procedures • Functions • Rules • Defaults • Cursors • Triggers

  7. SQL Server Data types • Integer : Stores whole number • Float : Stores real numbers • Text : Stores characters • Decimal: Stores real numbers • Money : Stores monetary data. Supports 4 places after decimal • Date : Stores date and time • Binary : Stores images and other large objects • Miscellaneous : Different types special to SQL Server.

  8. Not null Constraints Database Constraints • A null value is an unknown • Null value is not as zero or space.

  9. Unique Constraints • every value in a column or set of columns must be unique. • When thereis not the primary key. • Example • no two employees can have the same phone number

  10. Primary key • The primary key value must be unique and not null. • Multiple UNIQUE constraints and only one Primary key in a Table .

  11. Foreign key • FOREIGN KEY in one table points to a PRIMARY KEY in another table. • prevents that invalid data form being inserted into the foreign key column

  12. Check Constraints • used to limit the value range that can be placed in a column. • Example : • A column must only include integers greater than 0

  13. DEFAULT Constraint • used to insert a default value into a column

  14. Transact-SQL Commands • Data Definition Language (DDL) • Create , Alter , Drop , Truncate • meant to deal with the structure of the database objects (the object itself) like tables, views, procedures and so on. • Data Manipulation Language (DML) • Insert , Delete , Update , SELECT • deal with the contents of the tables rather than the structure of the tables • Data Control Language (DCL) • GRANT , DENY , REVOKE • maintain security of the database objects access and use

  15. Data Definition Language (DDL) • CREATE • adding a new database object to the database • ALTER • changing the structure of an existing database object • DROP • removing a database object from the database permanently • TRUNCATE • removing all rows from a table without logging the individual row deletions

  16. Data Manipulation Language (DML) • SELECT • retrieving data from the database by specifying which columns and rows to be retrieved • INSERT • adding a new row (and not column) into the table • UPDATE • modifying the existing data in the tabl • DELETE • removing an existing data from the table

  17. Data Control Language (DCL) • GRANT • giving privileges to the users • DENY • denies permissions from a security account in the current database and prevents the security account from inheriting the permission through its group or role memberships • REVOKE • removing privileges from the users that are previously granted those permissions

  18. SELECT • Definition • Retrieve data from database • Syntax SELECT * | column1 [, column2, …….] FROM table

  19. Example

  20. WHERE • Definition • Specify a condition to limit the result • Syntax SELECT * | column1 [, column2, …….] FROM table [WHERE conditions]

  21. Example

  22. IS Null Function

  23. Order BY • Definition • sort the retrieved rows by a specific column or set of columns • Syntax SELECT * | column1 [, column2, …….] FROM table [WHERE conditions] [ORDER BY column1 [, column2, ……..] ASC, DESC]

  24. Example

  25. Examples : Sort Descending 1 2

  26. Concatenate

  27. Aliases (as)

  28. Distinct • eliminates duplicate row values from the results • Example : the Next Slide

  29. Example: Distinct

  30. Grouping Data

  31. Grouping Functions

  32. Example 1: SUM

  33. Example 2 : SUM

  34. Group By • Definition • used to divide the rows in a table into smaller groups • Syntax SELECT * | column1, group_function (column2), ……. FROM table [WHERE conditions] [GROUPBY column1, ……..] [ORDER BY column1 [, column2, ……..] ASC, DESC]

  35. Example : Group By

  36. Having • Definition • used to restrict the group results • Syntax SELECT * | column1, group_function (column2), ……. FROM table [WHERE conditions] [GROUPBY column1, ……..] HAVING [conditions] [ORDERBY column1 [, column2, ……..] ASC, DESC]

  37. Example : Having

  38. SQL Operators

  39. Using SQL Operators • Arithmetic operators • Comparison operators • Logical operators • Set Operators • Other operators

  40. Arithmetic operators • addition (+) • subtraction (-) • multiplication (*) • division (/).

  41. Comparison operators • compare two or more values

  42. Example

  43. Logical operators • Used to get a logical value (True or False)

  44. Example

  45. Set Operators • Definition • combine the results of two or more queries into one result • Keywords • UNION/ UNION ALL • INTERSECT • EXCEPT

  46. UNION & Intersect & Except

  47. Union Operator • Create a Single Result Set from Multiple Queries • Each Query Must Have: • Similar data types • Same number of columns • Same column order in select list USE northwind SELECT(firstname + ' ' + lastname)ASname,city, postalcode FROM employees UNION SELECT companyname, city, postalcode FROM customers GO

  48. INTERSECT Operator • Definition • returns only the records that have the same values in the selected columns in both tables. • Syntax USE northwind SELECT(firstname + ' ' + lastname)ASname,city, postalcode FROM employees INTERSECT SELECT companyname, city, postalcode FROM customers GO

  49. EXCEPT Operator • Definition • return rows returned by the first query that are not present in the second query • Syntax USE northwind SELECT(firstname + ' ' + lastname)ASname,city, postalcode FROM employees EXCEPT SELECT companyname, city, postalcode FROM customers GO

  50. Other operators

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