(8) Working With Postgre Sql :-
we will talk about :-

• PGQuery().
• PGadd2db().
• PGresult().
• PGdelete().
• pgupdatedb()

How To connect to PostgreSql Database:-

• (1) Create An Object from Dragon-PostGreSql-Ext in the route.ring file :-
  

  oDPG = new DpG

• (Or) Use Importlib(cLibName) in manage.ring file to import the lib to
  "Batch/ImportedLibs" file then load it in Route.ring file...
• (2) Make Sure To Set This Connection Values Like
  

  oDPG = new DpG
      oDPG{
          pg_username = "postgres"
          pg_password = " "
          pg_database = "Dragon_ring"
          pg_port     = "5432"
          pg_conn     = NULL
  }

PG --> means Postgre Sql

PGQuery(Statement)

This function take one parameter contain sql statement.

PGADD2DB(Table_name , Table_values).

This function take two parameters as :-

• Table_name :- the name of the table and tables columns if you want ...
• Table_values :- list of values you want to add to PostgreSql database .

For example:-

#!ring -cgi 
load 'dragon-ring.ring'
import system.Web
oDPG = new DpG
    oDPG{
        pg_username = "postgres"
        pg_password = " "
        pg_database = "Dragon_ring"
        pg_port     = "5432"
        pg_conn     = NULL
        PGADD2DB('employees(id , name , salary)' , [1, "Mohannad" , 1800] )
        }

PGRESULT(select_statment).
For example :-

#!ring -cgi 
load 'dragon-ring.ring'
import system.Web
oDPG = new DpG
    oDPG{
        pg_username = "postgres"
        pg_password = " "
        pg_database = "Dragon_ring"
        pg_port     = "5432"
        pg_conn     = NULL
/* This code has written in route.ring (just for testing) */
res = PGRESULT('SELECT * From employees ;')
for col=1 to len(res)
    for row=1 to len(res[col])
        html(res[col][row] + TAB) 
    next
    html('<br/>')
next
}

The result is :-

      id        name        salary
      1       Mohannad       1800  

PGDELETE(table_name , column_name , column_value).

This function take three parameters :-

• table_name :- The name of the table .
• column_name :- The parimary key column like ( id ) .
• column_value :- The Value of the parimary key (column_name).

#!ring -cgi 
load 'dragon-ring.ring'
import system.Web
oDPG = new DpG
    oDPG{
        pg_username = "postgres"
        pg_password = " "
        pg_database = "Dragon_ring"
        pg_port     = "5432"
        pg_conn     = NULL
/* This code has written in route.ring (just for testing) */
PGDELETE('employees' , 'id' , 1 ) 
/* This code will delete the id,name,salary from database for the employee id 1 */
}

PGUPDATEDB(table_name,column_name,column_value,columns_names,columns_values) This function take five parameters :-

• table_name:- The name of the Table .
• column_name :- the name of the column you want to update by .
• column_value :-The Value of (column_name).
• columns_names :- list of columns that you want to update.
• columns_values :- list of values that you want to update (depending columns_names)

#!ring -cgi 
load 'dragon-ring.ring'
import system.Web
oDPG = new DpG
    oDPG{
        pg_username = "postgres"
        pg_password = " "
        pg_database = "Dragon_ring"
        pg_port     = "5432"
        pg_conn     = NULL
/* This code has written in route.ring (just for testing) */
table_columns = [ "id" , "name" , "salary" ] 
Table_values  = [ 2 , "Mohannad Aldulaimi" , 1700]
PGUPDATEDB('employees', 'id' , 1 ,table_columns, Table_values)
}

this function will make a sql statement like this :-
(UPDATE 'employees' SET id=2 ,name="Mohannad Aldulaimi" , salary=1700 where id=1)

I hope it was easy for you ...