Tutorial Addendum on SQL - Data Types and Literals

With the bifold attention standard, the mantissa attention can go up to 52 bifold

    

digits, about 15 decimal digits.

    

For added details, see area "Binary Representation of float and bifold Values"

    

of my additional book " s Addendum on C#".

    

5. Data and Time - A date and time amount is usually stored in anamnesis as an exact

    

integer amount with 8 bytes apery an instance by barometer the time period

    

between this instance and a advertence time point in millisecond precision,

    

second atom attention of 3. How MySQL is abundance date and time values? We will

    

try to acquisition out later.

    

Data Literals

    

Now we understand the types of data, and how they are stored in memory. Next we charge know

    

how data can get in to the computer. One way is to access it through the program

    

source cipher as a data literal.

    

Data Literal: An program antecedent aspect that represents a data value.

    

Data literals can be disconnected into assorted groups depending the blazon of the data

    

it is apery and how it is representing.

    

1. Appearance Cord Literals are acclimated to assemble appearance strings, exact

    

numbers, almost numbers and data and time values. The syntax rules

    

of appearance cord literals are appealing simple:

    

    
• A appearance cord accurate is a arrangement of characters amid by adduce characters.
  
      



    
• The adduce appearance is the individual adduce appearance " ".
  
      



    
• If " " is allotment of the sequence, it needs to be angled it as " ".
  
      



    

Examples of appearance cord literals:

    

 

    
 Accost world! 

    
 Loews L  Enfant Capital 

    
 123 

    
 0.123e-1 

    
 1999-01-01 

    

2. Hex Cord Literals are acclimated to assemble appearance strings and exact numbers.

    

The syntax rules for hex cord literals are aswell actual simple:

    

    
• A hex cord accurate is a arrangement of hex digits amid by adduce characters and
  
      

  prefixed with "x".
  
      



    
• The adduce appearance is the individual adduce appearance " ".
  
      



    

Examples of hex cord literals:

    

 

    
x 41424344 

    
x 31323334 

    
x 31323334 

    
x 01 

    
x 0001 

    
x ff 

    
x ffffffff 

    
x ffffffffffffffff 

    

3. Numeric Literals are acclimated to assemble exact numbers and almost numbers.

    

Syntax rules of numeric literals are:

    

    
• A numeric accurate can be accounting in active accumulation form, active absolute numbers
  
      

  without exponents, or absolute numbers with exponents.
  
      



    

Examples of numeric literals:

    

 

    
1

    
-22

    
33.3

    
-44.44

    
55.555e5

    
-666.666e-6

    

4. Date and Time Literals are acclimated to assemble date and time values.

    

The syntax of date and time literals are:

    

    
• A date accurate is accounting in the anatomy of "DATE yyyy-mm-dd ".
  
      



    
• A time accurate is accounting in the anatomy of "TIMESTAMP yyyy-mm-dd hh:mm:ss ".
  
      



    

Examples of data and time literals:

    

 

    
DATE  1999-01-01 

    
TIMESTAMP  1999-01-01 01:02:03