Wednesday 11 December 2013

Some SQL tips

Hi,

Many times I stacked into my work when I start using SQL. So here are some SQL tips and solutions. Read it and enjoy.

What is SQL?

SQL is Structured Query Language, which is a computer language for storing, manipulating and retrieving data stored in relational database.
SQL is the standard language for Relation Database System. All relational database management systems like MySQL, MS Access, Oracle, Sybase, Informix, postgres and SQL Server use SQL as standard database language.

Why SQL?

  • Allows users to access data in relational database management systems.
  • Allows users to describe the data.
  • Allows users to define the data in database and manipulate that data.
  • Allows to embed within other languages using SQL modules, libraries & pre-compilers.
  • Allows users to create and drop databases and tables.
  • Allows users to create view, stored procedure, functions in a database.
  • Allows users to set permissions on tables, procedures, and views

SQL Commands:

The standard SQL commands to interact with relational databases are CREATE, SELECT, INSERT, UPDATE, DELETE and DROP. These commands can be classified into groups based on their nature:

DDL - Data Definition Language:

CommandDescription
CREATECreates a new table, a view of a table, or other object in database
ALTERModifies an existing database object, such as a table.
DROPDeletes an entire table, a view of a table or other object in the database.

DML - Data Manipulation Language:

CommandDescription
SELECTRetrieves certain records from one or more tables
INSERTCreates a record
UPDATEModifies records
DELETEDeletes records

DCL - Data Control Language:

CommandDescription
GRANTGives a privilege to user
REVOKETakes back privileges granted from user

I will add more content to this in upcoming days. Till then keep reading.
 

Tuesday 3 December 2013

Decimal place

Hi,
 
Whenever we implement payment related things and we are using decimal values,
it happens that we need to allow 2 digit or three digit after decimal place.
Here is the code for the same. Below you can see two set of code.
 
One is for general use and other we can use at the place where we are using 
culture base implementation.
 
Simple:
 
This is the simple code to allow only two digit after decimal.
This will auto correct the value to two decimal place.
 
 function validNum(ctrl) {
        $(ctrl).val(parseFloat($(ctrl).val(), 10).toFixed(2));
    }
 
Culture based:

 Below code will show to use this when playing with multiple cultures.
 
var DecimalSeperator=',';  //This is for sweden culture 
   function roundDecimalValue(ctrl, roundedValue) {
        var value = $(ctrl).val().trim();
        if (value.length>0) {
            value = value.replace(DecimalSeperator, ".");
            value = parseFloat(value, 10).toFixed(roundedValue);
            // alert(val + "|" + $(ctrl).val());
            value = value.replace(".", DecimalSeperator);
            $(ctrl).val(value);
        }
    } 
 
 
Hope this can help you.