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Tuesday 27 May 2014

How to rename an existing column using sp_rename

In this video I am showing how to rename an existing column using sp_rename.


Thx,
RS

Sunday 25 May 2014

SQL Server Basics

This post is for Basics of SQL Server. I will cover below topics in this post

  • Create Table
  • Data Types
  • Variable Declaration
  • CURD Operations 
  • Joins Operators

Create Table

SQL server gives you the provision of creating table using design mode. Here I am showing the example How to create with query prompt.


CREATE Table TestTable1
(
      Id BIGINT
      ,Column1 VARCHAR(150)
      ,Column2 BIGINT
      ,Column3 DATETIME
)

This example is only for creating the table. While creating the table we can create the primary key, Index or we can the other properties as well.

Data Types

SQL-Server is having so many data types. I have already explain all the data types in this Link

Variable Declarations

In SQL-Server we can declare the variable using below syntax.

DECLARE @Temp VARCHAR(50)

SQL-Server 2012 we can declare and assign the variable at the same time

DECLARE @Temp VARCHAR(50) = 'Rahul Singi'

CURD Operations


Insert Statements:  Below is the example of insert data in table


INSERT INTO [dbo].[TestTable1]
          ([Id]
           ,[Column1]
              ,[Column2]
           ,[Column3])
    VALUES
             (1001
              ,'Rahul Singi'
           ,5001
           ,'02-23-1985')

INSERT INTO [dbo].[TestTable1] VALUES (1002 ,'Rahul Singi' ,5001 ,'02-23-1985')

For More detail you can use this Link

Update Statements:  Below is the example of Update data in table

     UPDATE TestTable1 SET Column1 = 'Gaurav' WHERE Id = 1002

If we will not use WHERE clause in update statement then it will update all the rows of the table. 
     For More detail you can use this Link
     Select Statements: Below is the example of Select data in table. Select statement begins with the list of columns or expressions. At least one expression is required.

SELECT 1

SELECT GETDATE()

SELECT
      [Column1]
      ,[Column2]
      ,[Column3]
FROM
      TestTable1

From portion of the select statement assembles all the data source into a result set, which is then acted upon by the rest of the SELECT statements.
WHERE clause acts upon the record set  assembled by the FROM clause to filter certain rows based upon condition.
     
    For More detail you can use this Link

    Delete Statements: Below is the example of Select data in table

DELETE FROM TestTable1 WHERE Id = 1001

    For More detail you can use this Link

   Join Operators
   
   Inner Join: Inner join will give you the result of common rows from the two tables. Below is the pictorial representation of inner join
Below is the example query:

SELECT
      *
FROM
      TestTable1 T1
INNER JOIN
      TestTable2 T2
      ON
T1.id = T2.Id

    Outer Joins: There are three types of Outer Join.

    Left Outer Join: Left join will give you the result of common rows from the two tables and all the data from Left table. Below is the pictorial representation of Left Join
Below is the example query:


SELECT
      *
FROM
      TestTable1 T1
LEFT JOIN
      TestTable2 T2
      ON
      T1.id = T2.Id

     Right Outer Join: Right join will give you the result of common rows from the two tables and all the data from Right table. Below is the pictorial representation of Right Join
Below is the example query:


SELECT
      *
FROM
      TestTable1 T1
RIGHT JOIN
      TestTable2 T2
      ON
T1.id = T2.Id

     Full Outer Join: Full join will give you the result of all rows. Below is the pictorial representation of Full Join.
Below is the example query:

SELECT
      *
FROM
      TestTable1 T1
FULL OUTER JOIN
      TestTable2 T2
      ON
T1.id = T2.Id
    
    Thx,
    RS

Saturday 24 May 2014

SQL Server 2012 Data Type


Below is the list of SQL -Server 2012 Data Type


Thx,
RS

Change select * with Select columns


This is my first video article in this I am showing how to replace select * from will all the columns 


Thx,
RS

SQL formatting standards

In my job we are following some formatting standards for SQL. I have searched over the internet and found that every company is having their own SQL formatting standards. But these are the very common standards which every company is using. Below are the some examples to cover all the query.

Example of SELECT statement:

SELECT
    ST.ColumnName1,
    JT.ColumnName2,
    SJT.ColumnName3
FROM
    FirstTable FT
INNER JOIN
    SecondTable ST
ON
    FT.Id = ST.Id
    AND
    FT.ColumnName = ST.ColumnName
INNER JOIN
    ThirdTable TT
ON
    ST.SourceTableID = TT.SourceTableID
    AND
    ST.Column3 = TT.Column4
WHERE
    ST.SourceTableID = X
    AND
    TT.Column3 = Y

Example of UPDATE statement:

UPDATE
    TestTable
SET
    ColumnName1 = @value,
    ColumnName2 = @value2
WHERE
    Condition1 = @test

Example of INSERT statement:

INSERT INTO TestTable
(
    ColumnName1,
    ColumnName2,
    ColumnName3
)
VALUES
(
    @value1,
    @value2,
    @value3
)

Example of IF Block statement:

IF (Condition)
BEGIN
      --Logic
END


Thx,
RS