Allocation memory for a variable...

• Flavio

  Right there with Babe

  Points: 793

  More actions

  May 17, 2002 at 9:51 am

  #78445

  When is allocate memory for a variable in a Script T-SQL?

  In the DECLARE instruction?

  Or in the SET education?

  Please, What is the difference between the CHAR() datatype and the the VARCHAR() datatype?

  How is allocate the memory for the two datatype?

  Thanks!!

  Ciao da Flavio

  PS

  Please, excuse me for possible grammar mistakes

• nagdimunovd

  SSC-Addicted

  Points: 496

  More actions

  May 17, 2002 at 10:01 am

  #429375

  Char is spacepadded, varchar is variable length.

  IF you use datalength function of @CharType char(10) it will always return 10, if you use same variable declared as varchar(10) and the value of the variable is "Hello" it will return 5

  Here is a sample:

  Declare @dude char(10)

  Declare @dude2 varchar(10)

  SET @dude = ''

  SET @dude2 = ''

  PRINT DataLength(@dude)

  PRINT DataLength(@dude2)

  quote:

  ---

  When is allocate memory for a variable in a Script T-SQL?

  In the DECLARE instruction?

  Or in the SET education?

  Please, What is the difference between the CHAR() datatype and the the VARCHAR() datatype?

  How is allocate the memory for the two datatype?

  Thanks!!

  Ciao da Flavio

  PS

  Please, excuse me for possible grammar mistakes

  ---

• Antares686

  SSC Guru

  Points: 125444

  More actions

  May 17, 2002 at 10:04 am

  #429378

  Memory is allocated when a variable is declared and the data is altered when it is set.

  "Don't roll your eyes at me. I will tape them in place." (Teacher on Boston Public)

• nagdimunovd

  SSC-Addicted

  Points: 496

  More actions

  May 17, 2002 at 10:04 am

  #429377

  Oh yeah I forgot to mention if you have not assigned default value to a variable, and it contains a null value the datalength will be zero.

• Jorge Cordero

  Ten Centuries

  Points: 1144

  More actions

  May 23, 2002 at 4:53 pm

  #429706

  And also varchar() takes a little more memory than char() when char(n) column doesn't allow nulls (because there is no need to register the actual size).

  In variables, they use the same amount of memory but have different behavior.

  quote:

  ---

  When is allocate memory for a variable in a Script T-SQL?

  In the DECLARE instruction?

  Or in the SET education?

  Please, What is the difference between the CHAR() datatype and the the VARCHAR() datatype?

  How is allocate the memory for the two datatype?

  Thanks!!

  Ciao da Flavio

  PS

  Please, excuse me for possible grammar mistakes

  ---