Ruinas

Cursores
Los cursores son una herramienta de SQL que nos permite recorrer el resultado de una consulta SQL y realizar operaciones en cada paso de ésta.
Es así como nos ayuda a realizar operacionesque de otro modo serían más complejas o irrealizables.
La syntax se presenta a continuación.

ISO Syntax
DECLARE cursor_name [ INSENSITIVE ] [ SCROLL ] CURSOR
FOR select_statement
[FOR { READ ONLY | UPDATE [ OF column_name [ ,...n ] ] } ]
[;]
Transact-SQL Extended Syntax
DECLARE cursor_name CURSOR [ LOCAL | GLOBAL ]
[ FORWARD_ONLY | SCROLL ]
[ STATIC | KEYSET |DYNAMIC | FAST_FORWARD ]
[ READ_ONLY | SCROLL_LOCKS | OPTIMISTIC ]
[ TYPE_WARNING ]
FOR select_statement
[ FOR UPDATE [ OF column_name [ ,...n ] ] ]
[;]

Processing ofStored Procedures

Parsing
The parser checks for correct syntax, including the correct spelling and use of keywords. The normalizer's main function is to perform binding, which means checkingwhether tables and columns exist, loading meta data about the tables and columns, and adding information about required (implicit) conversions to the sequence tree (an internal data structure that storesinformation about the query). Normalization also replaces references to a view with the definition of that view and performs a few syntax-based optimizations. These syntax optimizations includeconverting right outer joins to equivalent left outer joins, flattening sub-queries to an equivalent join syntax, and simplifying some negative expressions.
Resolving
When a stored procedure is created allobjects referenced are resolved (checked to see whether or not they exist).
The create will succeed even if the objects do not exist
Compiling
The query processor looks for statements that theoptimization process won't include and runs the statements through a T-SQL language compiler. These statements (e.g., variable declarations and assignments, conditional processing with IF, and...