plsql_Implicit_cursor1.htm |
Cursor:
One of the best reference : http://www.postgresql.org/docs/9.2/static/plpgsql-cursors.html#PLPGSQL-CURSOR-FOR-LOOP |
The concept of Cursors in dbms remained hot discussion area, I
agreed with few of the following views and references.
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Cursor is a work area or a memory space to store processing information at the server end. A SQL statement induce an implicit cursor, similar to the address of (&) operation with a pointer in C++, in at the server end |
Code Used : Code_JavaApp1.txt |
Consider This screen shot to emphasize the role of an implicit
cursor . I used NetBean 7.X Tool from Oracle corporation, and PostgreSQL
database.
Not the highlighted code script-snippet, the resultset processed an array like a block with wile control structure, where indices (range 1- through 4, as row-counts) were strictly enforced. If we change the sequence, we would notice an run time error. Unlike an array, the first row count starts with 1.
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Pros and Cons: The table shown below has 8 column
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Edit the current SQL statement :
In the above conditin the columns can be shuffled as desired.
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