Switch database on PGSQL

To switch to another database when connect to PostgreSQL Server use following command on psql.

postgres=>\connect databasename

postgres=> \c databasename

For eg: Lets say you are connected to default postgres database and want to connect to database name mydatabase, try below syntax

postgres=> \c mydatabase or postgres=> \connect mydatabase

mydatabase=>

Commonly use oracle queries and commands

To View all databases 

SQL> SELECT NAME FROM v$database

Shutdown database

SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.

Start the instance

SQL> startup;

ORACLE instance started.

Total System Global Area 4966053832 bytes
Fixed Size                  8906696 bytes
Variable Size             922746880 bytes
Database Buffers         4026531840 bytes
Redo Buffers                7868416 bytes
Database mounted

Open the database

SQL> alter database open;

SQL> select instance_name, status from v$instance;

INSTANCE_NAME    STATUS
---------------- ------------
orcl             MOUNTED

SQL> alter database open;
Database altered.

SQL> select instance_name, status from v$instance;
INSTANCE_NAME    STATUS
---------------- ------------
orcl            OPEN

MariaDB delete duplicate using ROW_NUMBER()

Please note : Window Functions are available in MariaDB 10.2 onwards

In our previous article, we talked about deleting duplicate data in MySQL using join. In this article we are going to demo on how to delete duplicate using row_number(). Since we already have our demo table created with dummy data, going ahead directly with the query

Step 1: Find duplicate using row_number()

SELECT  id  FROM (SELECT id, ROW_NUMBER() OVER(PARTITION BY name ORDER BY name) AS row_num FROM demo) d WHERE row_num > 1;
+------+
| id   |
+------+
|    7 |
|    3 |
+------+
2 rows in set (0.000 sec)

Step 2: Select * from demo

 select * from demo;

+------+--------+

| id   | name   |

+------+--------+

|    1 | abc    |

|    2 | abd    |

|    3 | vijay  |

|    4 | vijay  |

|    5 | ajay   |

|    6 | sanjay |

|    7 | vijay  |

+------+--------+

7 rows in set (0.000 sec)

Step 3: Delete duplicate

DELETE FROM demo WHERE id IN (SELECT id FROM (SELECT id,ROW_NUMBER() OVER (PARTITION BY name ORDER BY name) AS row_num FROM demo) d  WHERE row_num > 1);
Query OK, 2 rows affected (0.005 sec)

Step 4: Check if duplicate values are deleted using step 2 query

SELECT  id  FROM (SELECT id, ROW_NUMBER() OVER(PARTITION BY name ORDER BY name) AS row_num FROM demo) d WHERE row_num > 1;
Empty set (0.000 sec)

Done, duplicate data deleted.

Powershell to find Text in PDF and Word

In continuation to my previous article on PowerShell to find hyperlink texts in ppt, here I am going to show how to find hyperlinks in Word or PDF files. Sample code below, tweak it for your purpose and drop me a comment if you need help.

$FilePath= "C:\Users\xxx\" 

$OurDocuments = Get-ChildItem -Path "$FilePath" -Filter "*.pdf" -Recurse #change to .doc* for word

$Word = New-Object -ComObject word.application

$Word.Visible = $false

$i = 0

$OurDocuments | ForEach-Object {

try {

    $Document = $Word.Documents.Open($_.FullName,$false,$true) 

    #"Processing file: {0}" -f $Document.FullName

    

    try{

    $Document.Hyperlinks | ForEach-Object {

        if ($_.Address -like "https://domain.com*" -or $_.Text -like "https://domain.com*") 

        {

                "Found issues {0} `r`n" -f $Document.Fullname 

                "Found issues {0} `r`n" -f $_.Address

                "Found issues {0} `r`n" -f $_.Hyperlinks

                break

         } 

      

    }

    }catch{Write-Host "Error has occured while accessing" $Document.FullName}

    }

    catch{Write-Error $Document.FullName}

   #"Completed processing {0} `r`n" -f $Document.Fullname

    

  Write-Progress -Activity "Searching Hyperlinks" -Status "Progress:" -PercentComplete ($i/$OurDocuments.count*100)

  $i++

}

$Word.Quit()

[gc]::collect()

[gc]::WaitForPendingFinalizers()

PowerShell to find HyperLink Text in PowerPoint

Recently I faced a scenario where I needed to find if a particular url is used in hyperlink in 100s of ppt. Opening ppt and looking for the ppt is cumbersome,  so wrote a small PowerShell to find the url. Here is the PowerShell Script code

Click here to view article on powershell to find hyerlink text in word or pdf

$FilePath= "C:\Users\xxx\Path"

Add-Type -AssemblyName Office

$ppt = New-Object -ComObject powerpoint.Application

$DocumentsLib = Get-ChildItem -Path "$FilePath" -Filter "*.ppt*" -Recurse

$Doc = New-Object -ComObject powerpoint.Application

$i=0

$DocumentsLib | ForEach-Object {

Write-Host $_.FullName

$Doc = $ppt.Presentations.Open($_.FullName,$Null,$Null,[Microsoft.Office.Core.MsoTriState]::msoFalse)

$Slides = $Doc.Slides

Foreach ($Slide in $Slides) {

    $Slide.Hyperlinks | ForEach-Object {

       

        if ($_.Address -like "*texttofind*" -or $_.Text -like "texttofind*") 

        {

           write-host $_.Address

           write-host "Found"

            break

        }

               

 }

}

#$Doc.Save()

#$Doc.Close($false)

#$ppt = $null

 Write-Progress -Activity "Searching Hyperlinks" -Status "Progress:" -PercentComplete ($i/$DocumentsLib.count*100)

  $i++

}

[gc]::collect()

[gc]::WaitForPendingFinalizers() 

Drop Database in Oracle

Steps to drop a container database in oracle

Step 1 : Connect to the database as sysdba

bash#$ sqlplus / as sysdba

Step 2 : Shutdown the database

SQL> shutdown immediate;

Step 3 : Start mount the database with exclusive restrict to avoid the database being opened

SQL> startup mount exclusive restrict;

Step 4 : Drop database

SQL> drop database;

Getting Started with MariaDB

In our previous post, we demonstrated steps to install MariaDB Server on Ubuntu, in this article, we are going to show how to create database in MySQL/MariaDB. We are going to talk about DDL(Data Definition Language), how to create tables and authorize users to access them.

Start your mariadb-server and follow the steps

Creating Databases, Tables, and Authorized Users

Step 1: Connect to your mariadb-server and run below sql. This can be done via mysql client or any other tools like Heidisql, phpmyadmin etc. This is going to create a new database in your server. 

CREATE DATABASE myFirstDB;

Check if the database already exists and create

CREATE DATABASE IF NOT EXISTS myFirstDB;

To list all the databases in a server.

SHOW DATABASES;

To connect to your database

USE DATABASE_NAME;

Once you have selected your database, use following to create user

CREATE USER 'username'@'localhost' IDENTIFIED BY 'user_password';

To create a user that can connect from any host, use the '%' wildcard as a host part:

CREATE USER 'username'@'%' IDENTIFIED BY 'user_password';

No you can login to your MariaDB using the new user and password

mysql -h localhost -P port -u username -p user_password